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Intramuscular stimulation for chronic myofascial pain Lau, Choi Chun 2010

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INTRAMUSCULAR STIMULATION FOR CHRONIC MYOFASCIAL PAIN  by Choi Chun Lau B.Sc., The University of Hong Kong, 2004  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in The Faculty of Graduate Studies (Experimental Medicine)  THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2010  © Choi Chun Lau, 2010  ABSTRACT  Background: Myofascial pain is a common musculoskeletal disorder characterized by muscles in a contracted state with increased tone and stiffness. It is one of the most common chronic pain syndromes that lead to disability and lower quality of life, creating a significant public health and economic burden. Intramuscular stimulation (IMS) is a dry needling technique that targets specifically chronic myofascial pain and is utilized in multidisciplinary pain centers around the world. Despite its wide use, the effect of IMS has been poorly studied. Methods: We conducted two chart reviews to generate information regarding IMS effectiveness and the feasibility of conducting a randomized clinical trial (RCT). Success rate of pain improvement (at least 1 unit reduction on pain score) was documented in percentage. In addition, an inter-rater reliability test was conducted to assess the consistency among IMS practitioners in examining patients. Intra-class correlation coefficient (ICC) and multiple-raters kappa were used to assess the agreement between practitioners in identifying number of taut bands and identifying taut bands in each muscle respectively. Results: From the two chart reviews, we found that a majority of patients (nearly 30%) had their pain for 10 or more years. Most of them had chronic low back pain. The percentage of success was at least 34% (95% CI: 25%, 43%) and 30% (95% CI: 22%, 38%) for worst and average pain (last week) respectively. For inter-rater reliability test, ICC values ranged from 0.64 to 0.77 (substantial agreement) but kappa values of identifying tender taut band in each muscle were ranged from -0.05 (poor agreement) to 0.46 (moderate agreement). Conclusion: Chart review showed positive results regarding short-term effect of IMS in relieving chronic pain and improving pain consequences. Given the difficulty in treating chronic pain, it is worth conducting a sham controlled RCT to further evaluate the effect of IMS. Population characteristics and success rate of pain improvement will be used in justifying the type and size of sample in the design of a RCT. Good consistency among practitioners in treating patients has to be achieved before conducting the RCT.  ii  TABLE OF CONTENTS ABSTRACT........................................................................................................................ ii TABLE OF CONTENTS ................................................................................................... iii LIST OF TABLES ............................................................................................................. vi LIST OF FIGURES .......................................................................................................... vii ACKNOWLEDGEMENTS............................................................................................. viii CHAPTER 1: Introduction ................................................................................................. 1 1.1 Overview......................................................................................................... 1 1.2 Evaluation Strategy ......................................................................................... 2 1.3 Structure of Thesis .......................................................................................... 3 CHAPTER 2: Review of Literature.................................................................................... 4 2.1 2.2 2.3  Introduction..................................................................................................... 4 Pain and Chronic Pain..................................................................................... 4 Myofascial Pain .............................................................................................. 6 2.3.1 Definitions........................................................................................... 6 2.3.2 Epidemiology...................................................................................... 6 2.3.3 Symptoms and Diagnosis.................................................................... 7 2.3.4 Perpetuating Factors and Types of Myofascial Pain........................... 8 2.3.5 Pathophysiology.................................................................................. 8 2.3.6 Treatments......................................................................................... 11 CHAPTER 3: Rationale, Objectives and Hypothesis ....................................................... 22 3.1 Rationale ..................................................................................................... 22 3.2 Objectives and Hypothesis.......................................................................... 22 CHAPTER 4: Study 1-Documentation of the Effect of Intramuscular Stimulation to Treat Chronic Myofascial Pain: A Chart Review....................................................................... 24 4.1 4.2  Introduction................................................................................................. 24 Methods....................................................................................................... 24 4.2.1 Study Design..................................................................................... 24 4.2.2 Study Population............................................................................... 24 4.2.3 Study Procedure ................................................................................ 24 4.2.4 Ethics................................................................................................. 25 4.2.5 Statistical Analysis ............................................................................ 25 4.3 Results......................................................................................................... 26 4.3.1 Chart Review .................................................................................... 26 4.3.2 Telephone Interview.......................................................................... 27 4.4 Discussion ................................................................................................... 28 4.5 Conclusion .................................................................................................. 30 CHAPTER 5: Study 2-Documentation of the Effect of Intramuscular Stimulation to Treat Chronic Myofascial Pain: Second Chart Review.............................................................. 31  iii  5.1 5.2  Introduction................................................................................................. 31 Methods....................................................................................................... 31 5.2.1 Study Design and Sample Size ......................................................... 31 5.2.2 Study Population............................................................................... 32 5.2.3 Chart Review Process ....................................................................... 32 5.2.4 Chart Information.............................................................................. 32 5.2.5 Outcomes .......................................................................................... 33 5.2.6 Practitioners ...................................................................................... 34 5.2.7 Statistical Analysis ............................................................................ 34 5.2.8 Long Term Follow-up ....................................................................... 34 5.2.9 Ethics................................................................................................. 35 5.3 Results......................................................................................................... 35 5.3.1 Population Identification and Follow-up .......................................... 35 5.3.2 Population Characteristics ................................................................ 35 5.3.3 Pain Intensity Change on Brief Pain Inventory (BPI) ...................... 36 5.3.4 Disability and Quality of Life Items on Brief Pain Inventory (BPI) 36 5.3.5 Oswestry Low-Back Pain Disability Index (ODI)............................ 37 5.3.6 Pain Treatment Satisfaction Scale (PTSS)........................................ 37 5.3.7 Predictors for Improvement in Worst and Average Pain Score......... 38 5.4 Discussion ................................................................................................... 38 5.5 Conclusion .................................................................................................. 42 CHAPTER 6: Study 3-Assessing the Inter-Rater Reliability of Intramuscular Stimulation Practitioners ...................................................................................................................... 54 6.1 6.2  Introduction................................................................................................. 54 Methods....................................................................................................... 54 6.2.1 Study Design..................................................................................... 54 6.2.2 Study Sample .................................................................................... 54 6.2.3 Practitioners ...................................................................................... 55 6.2.4 Study Procedures .............................................................................. 55 6.2.5 Clinical Examination ........................................................................ 55 6.2.6 Outcome Measures............................................................................ 56 6.2.7 Ethics................................................................................................. 57 6.2.8 Statistical Analysis ............................................................................ 57 6.3 Results........................................................................................................... 58 6.3.1 Sample Characteristics...................................................................... 58 6.3.2 Inter-rater Reliability of Identifying Tender Taut Bands .................. 58 6.4 Discussion ..................................................................................................... 59 6.5 Conclusion .................................................................................................... 60 CHAPTER 7: Summary of Findings, Conclusion and Future Work ................................ 64 7.1 Introduction................................................................................................. 64 7.2 Summary of Findings.................................................................................. 64 7.3 Conclusion from the Three Studies............................................................. 67 7.4 Future Work: Conduct of RCT.................................................................... 67 CHAPTER 8: A Proposal for a Randomized Controlled Trial (RCT) .............................. 70  iv  8.1 Title of the Study Proposal............................................................................ 70 8.2 Background ................................................................................................... 70 8.3 Rationale ....................................................................................................... 79 8.4 Clinical Relevance ........................................................................................ 80 8.5 Study Objectives ........................................................................................... 81 8.6 Study Hypothesis .......................................................................................... 81 8.7 Study Design................................................................................................. 81 8.8 Sample Specification .................................................................................... 82 8.9 Interventions ................................................................................................. 83 8.10 Allocation of Intervention........................................................................... 84 8.11 Treatment Duration ..................................................................................... 85 8.12 Frequency and Duration of Follow-up........................................................ 85 8.13 Outcome Assessment .................................................................................. 86 8.14 Recruitment................................................................................................. 88 8.15 Retention Strategy....................................................................................... 89 8.16 Sample Size................................................................................................. 89 8.17 Statistical Analysis ...................................................................................... 89 8.18 Trial Management ....................................................................................... 90 8.19 Ethics........................................................................................................... 93 8.20 Budget ......................................................................................................... 93 BIBLIOGRAPHY............................................................................................................. 94 APPENDIX A: ADDITIONAL TABLES........................................................................111 APPENDIX B: HUMAN ETHICS APPROVAL CERTIFICATE...................................113    v  LIST OF TABLES Table 5.1: Demographic Characteristics of Patients Not Included in the Analysis .......... 43 Table 5.2: Demographic Characteristics ........................................................................... 44 Table 5.3: Distribution of Pain Intensity Change at Follow-up Using Available Data..... 45 Table 5.4: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Available Data ........................................................................................................ 45 Table 5.5: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Best Case Imputation.............................................................................................. 46 Table 5.6: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Worst Case Imputation ........................................................................................... 46 Table 5.7: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using LOCF...................................................................................................................... 46 Table 5.8: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Available Data ........................................................................................................ 47 Table 5.9: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Best Case Imputation.............................................................................................. 48 Table 5.10: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Worst Case Imputation ........................................................................................... 48 Table 5.11: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using LOCF...................................................................................................................... 48 Table 5.12: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Available Data................................................................................................................... 49 Table 5.13: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Sensitivity Analyses .......................................................................................................... 49 Table 5.14: Results from Pain Treatment Satisfaction Scale (PTSS) ............................... 50 Table 5.15: Results from Multiple Logistic Regression with Response = Worst Pain Improvement ..................................................................................................................... 52 Table 5.16: Results from Multiple Logistic Regression with Response = Average Pain Improvement ..................................................................................................................... 52 Table 6.1: Intra-class Correlation Coefficient (ICC) for Identifying the Number of Taut Bands in Different Regions............................................................................................... 61 Table 6.2: Multiple Raters Kappa of Identifying Taut Band in Each Back Muscle ......... 61 Table 6.3: Multiple Raters Kappa of Identifying Taut Band in Each Hip/Thigh Muscle . 62 Table 6.4: Multiple Raters Kappa of Identifying Taut Band in Leg Muscle .................... 63 Table 6.5: Multiple Raters Kappa of Identifying Autonomic Dysfunction ...................... 63  vi  LIST OF FIGURES Figure 5.1: Flow Chart for Population Identification……………………………………53  vii  ACKNOWLEDGEMENTS I offer my enduring gratitude to my supervisor, Dr. Jean-Paul Collet, for all his support, guidance, assistance and care during my study. I would like to thank my supervisory committee, Drs. Marc White, Millan Patel and Rollin Brant, for offering critical and insightful advice. I would also like to thank Dr. Gunn and the staff at Institute for the Study and Treatment of Pain (iSTOP) for their invaluable input and effort to this project. I am extremely grateful that I have wonderful colleagues and sweet friends to be always beside me and share my ups and downs. Lastly, I would like to sincerely thank my lovely family members for all their support, patience, care, warmth and love.  viii  CHAPTER 1: Introduction 1.1 Overview Myofascial pain or myofascial pain syndrome is a localized muscle pain syndrome that is characterized by muscles in a contracted state with increased tone and stiffness, and that contain myofascial trigger points (Simons et al 1999).  Myofascial trigger point (TrP)  was defined by Simons (1995, 1999) as self-sustaining hyperirritable spot located in taut band (contracted group of muscle fibers) of skeletal muscle or its associated fascia with zone of tenderness. Direct compression or palpation of TrP provokes radiating and aching type of pain into localized referred area namely referred pain (Wheeler 2004). Myofascial pain is one of the most common chronic pain syndromes (Gerwin 2001) that leads to disability and lower quality of life in individuals, creating a significant public health and economic burden (Weiner 2001).  Patients with TrP present clinical symptoms such as localized or regional deep aching sensations, hypersensitivity, allodynia (pain evoked by a non-painful stimulus), palpable nodules or taut bands with local tenderness, muscle weakness and decreased range of motion at sites of TrP (Borg-Stein et al 2002, Gerwin 2001, Harden et al 2000, Hong et al 1998, Simons et al 1999). Other functional complaints include decreased work tolerance, impaired muscle coordination, stiff joints and fatigue (Friction et al 1985). Myofascial pain is highly prevalent in patients with head and neck pain, shoulder pain, low back pain, leg pain and has been found to be associated with common chronic pain syndromes including peripheral neuropathy, radiculopathy, temporomandibular joint dysfunction and complex regional pain syndrome (Gunn 1997, Baldry 2001, Gerwin 2001, Backonja et al 1998).  Treatments for myofascial pain are diverse. General oral pharmacological treatment for myofascial pain includes non-steroid anti-inflammatory drugs (NSAIDs), opioid, antidepressants, anticonvulsants, muscle relaxants (Wheeler 2004, Borg-Stein et al 2002). These medications usually have limited long term efficacy and are often associated with numerous adverse events (Wheeler 2004). This is the reason why many patients try 1  alternative treatments such as massage and exercises (Baldry 2002, Cummings 2007, Han et al 1997), transcutaneous electrical nerve stimulation (TENS), low level laser therapy (LLLT) and dry needling. Although there is limited evidence on the effect of alleviating chronic pain for some alternative treatments, the whole field lacks serious study. Despite the presence of different kinds of treatment, patients with chronic myofascial pain patients are still under-treated (Breivik et al 2006, Robinson 2007).  Intramuscular stimulation (IMS) is a dry needling technique that targets specifically chronic regional myofascial pain and is utilized in multidisciplinary pain centers. It has been developed over 30 years and the IMS teaching professionals have been offering certified IMS training to several hundreds of pain practitioners in Canada, US and worldwide (including UK, Norway, Denmark, Korea, Malaysia and Singapore) (iSTOP 2007). Compared to Ah Shi acupuncture (a form of acupuncture that targets TrP and taut band), IMS approach targets not only TrP or taut band at limbs and trunk muscles, but also the innervated paraspinal muscles along the spine (Gunn 2007). Based on letters and testimonials it seems that many chronic pain patients appreciated the effects of IMS in alleviating their pain but there is no solid clinical evidence supporting its effect. With the wide use of the IMS technique and the absence of good conventional treatment for chronic myofascial pain, we felt that it was important to evaluate the effect of IMS so as to better inform patients the IMS effectiveness in alleviating chronic pain.  1.2 Evaluation Strategy To evaluate IMS efficacy and safety, we wanted to conduct a sham controlled randomized controlled trial (RCT). In the preparation phase of the RCT, we conducted a systematic review of patients’ charts in one IMS clinic in Vancouver to assess the IMS effect so as to help determining the sample size for the trial. The chart review was useful but also disappointing because there was missing information regarding patients’ improvement and the chart information was inconsistently recorded among the eight practitioners at the clinic. A meeting was held with IMS practitioners to discuss the problems and a new chart was then developed to systematically document patients’ signs and symptoms.  2  With the same objective, a second chart review was conducted 10 months after this new recording strategy had been implemented as part of normal practice. In addition, an inter-rater reliability test was carried out to evaluate the consistency of current five IMS practitioners in examining patients at the clinic. Finally, with all the information from the two chart reviews and the inter-rater reliability studies, the protocol of a RCT was developed and has been submitted for funding to the Canadian Institute for Health Research (CIHR). This thesis aims to present the methodology and results of these studies which serve as a rationale for the future RCT.  1.3 Structure of Thesis The thesis is structured as follow. Chapter two reviews the literature of myofascial pain, available treatments, dry needling and intramuscular stimulation. Chapter three presents rationale, objectives and hypotheses. Chapter four documents the results of the first chart review of patients treated at the IMS clinic. As the initial chart review did not provide enough information regarding the effect size of IMS, a second chart review was conducted systematically after implementing a new protocol. Chapter five describes the results from the second chart review. Details of inter-rater reliability test are presented in Chapter six. Chapter seven summarizes study results, presents general discussion and concludes the thesis with potential direction of future works. Lastly, chapter eight is the proposal of a randomized controlled trial that has been submitted to CIHR.  3  CHAPTER 2: Review of Literature 2.1 Introduction This chapter reviews the literature in relation to the thesis research question. Section 2.2 briefly presents the definition of pain and the burden of chronic pain in the society. Section 2.3 reviews the definition of myofascial pain (section 2.3.1), its epidemiology (section 2.3.2), diagnosis of myofascial pain (section 2.3.3), the perpetuating factors (section 2.3.4), pathophysiology of different types of myofascial pain (section 2.3.5) and different kinds of treatment available and the associated clinical evidence including intramuscular stimulation (section 2.3.6).  2.2 Pain and Chronic Pain Pain is a complex, emotional and subjective experience that is recognized and tolerated differently by individuals (Pain Resource Center 2002). According to the International Association for the Study of Pain (ISAP), pain is defined as the unpleasant physical sensation or emotional experience that is associated with either actual or potential damage to body tissues or nerves (Merskey 1994). Pain can be caused by single or multiple pathways. It can be produced by activation of specific nociceptors (receptors that are sensitive to noxious stimuli) due to external stimuli or due to diseases or tissue damage. This is characterized as nociceptive pain. It can also be the result of dysfunction or lesion in nervous system which is known as neuropathic pain. Finally, it can also arise from psychological factors such as depression and anxiety (Abram 2006, Robinson 2007, WHO 2008). Clinically, pain is often divided into two categories: acute and chronic pain (Harold 2003). Acute pain is a pain sensation with duration from seconds to days. It is usually the result of activation of nociceptors by noxious stimuli or tissue damage. Acute pain usually can be efficiently treated by removal of noxious stimuli or treatment of wound or disease and thus, in general, it does not present a serious burden to patients (Stefan et al 2004). Chronic pain is a continuous and recurrent pain that persists longer than the temporal 4  course of natural healing or more than three months (Robert 2002). It may persist long after initial injury or tissue damage has been healed. The reason for the development of chronic pain is multi-factorial and yet, not well understood. It is therefore difficult to cure and is a major public health problem worldwide. In 2000, chronic pain was listed as a disease by the World Health Organization (WHO) (American Chronic Pain Association 2004). Chronic pain affects millions of people throughout the world. In US, it was estimated 50 millions (about 20%) of people live with chronic pain caused by disease, disorder or accident (National Pain Survey 1999). A recent survey conducted in 15 European countries suggested that 19% of adults suffered from moderate to severe chronic pain at the time of survey being conducted (Breivik 2006). In China, a study showed that 62 percent of Chinese urban people aged between 33 and 55 had suffered from chronic pain in the back, neck, shoulders and limbs during their life course (People’s Daily Online 2004). Chronic pain is a frequent cause of disability and has an enormous negative impact on individual’s quality of life. Chronic pain diminishes patients’ ability to concentrate on their jobs, exercise, socialize, sleep and perform daily tasks (Weiner 2001) which engender downward spiral of depression, isolation and loss of self-esteem (Breivik 2006, Sternbach 1974, Sternbach 1977). The effect of chronic pain has profound implications to the society. It creates a significant public health and economic burden to the public (Jensen et al 2004). Chronic pain is one of the most common reasons that lead people to seek medical care; patients with chronic pain use health services up to five times more frequently than the rest of the population (Blyth et al 2004, Von et al 1990, Von et al 1991). For instance, chronic low back pain patients cost over USD$40 billion annually in direct medical treatment and costs associated with disability (Andersson 1999). Moreover, the cost related to the loss of productivity due to time off work, loss of skilled workers and reduced work efficiency has profound impact on the social economy (Blyth et al 2003). It is estimated that about  5  61.2 billion dollars was lost from loss of productivity due to pain conditions in the US workforce per year (Stewart et al 2003). One of the most common chronic pain syndromes is myofascial pain (Ashbum et al 1999).  2.3 Myofascial Pain 2.3.1  Definitions  Myofascial pain or myofascial pain syndrome is a localized muscle pain syndrome that is classified as a common musculoskeletal disorder (Gerwin 2001). It is characterized by muscles in a contracted state with increased tone and stiffness, and that contain myofascial trigger points (Simons et al 1999). Myofascial trigger point (TrP) was defined by Simons (1995, 1999) as self-sustaining hyperirritable spot located in taut band (contracted group of muscle fibers) of skeletal muscle or its associated fascia with zone of tenderness. Direct compression or palpation of TrP provokes radiating and aching type of pain into localized referred area namely referred pain (Wheeler 2004).  When needle  or mechanical stimuli is applied on TrP, it often elicits a local twitch response (LTR) which is a sharp contraction of muscle fibers, and that creates a strong patients’ reaction or “jump sign” (Gerwin 2001, Wheeler 2001). TrP can be divided into active or latent. Both active and latent TrP share similar characteristics as mentioned but latent TrP is only painful when palpated (Simons 1995).  2.3.2  Epidemiology  The prevalence of myofascial pain in the general population is unknown. However, it is extremely common and affects many individual’s life at one time (Mense et al 2001). A study of 200 young asymptomatic adults found that 54% males and 45% females had focal tenderness presenting latent TrP (Sola et al 1955). Other studies showed that myofascial pain is highly prevalent among patients with regional pain (localized pain) complaints. Fishbain et al. (1986) showed that among 283 chronic pain patients admitted to a pain center 85% had myofascial pain with TrP. More recently, a study by Gerwin (1995) showed that 74% of 96 patients with musculoskeletal pain seen by a neurologist in 6  a community pain medical center presented myofascial pain symptoms while another study (Lin et al 1997) found that 94.5% of 109 patients with musculoskeletal disorders were myofascial pain.  Myofascial pain is frequently associated with chronic head, neck and back pain (Simons 1988). In a study of 164 patients referred to a pain clinic with chronic head and neck pain, 55% were found to have myofascial pain (Friction et al 1985). In another study, Weiner (2006) showed that among 131 chronic low back pain patients, 95.5% of them had myofascial pain. Low back pain is considered to be frequently associated with myofascial pain (Borg-Stein et al 2002, Simons 1988, Weiner 2006).  2.3.3  Symptoms and Diagnosis  Diagnosis of myofascial pain is difficult because there is no objective assessment. Trigger point (TrP) identification relies exclusively on the quality of patients’ examination by palpation. Identifying taut band with tenderness is the key to locate contracted muscle fibers and subsequently TrP (Gerwin 2001). Patients with TrP present clinical symptoms such as localized or regional deep aching sensations, hypersensitivity, allodynia (pain evoked by a non-painful stimulus), palpable nodules or taut bands with local tenderness, muscle weakness and decreased range of motion at sites of TrP (Borg-Stein et al 2002, Gerwin 2001, Harden et al 2000, Hong et al 1998, Simons et al 1999). Other functional complaints include decreased work tolerance, impaired muscle coordination, stiff joints and fatigue (Friction et al 1985). Myofascial pain is usually not only localized, but also referred to a particular distance on compression of taut band. Referred pain pattern varies from muscles to muscles. Simons (1993) has estimated that referral patterns in 20% of muscles is in an upwards and downwards direction in response to the triggered muscle; 48% muscles have a downwards direction; in 5% of muscles it is in upwards direction; 10% is locally around the TrP; 17% is locally around and downwards.  Apart from abnormal sensation and motor limitations, signs of autonomic dysfunction 7  with increased sympathetic activity, including abnormal sweating (sudomotor reflex), decrease in skin temperature (vasomotor reflex), local skin oedema, goosebumps (pilomotor reflex) and some trophic changes such as dermatomal hair loss, cracking nails are found in most of the myofascial pain cases (Baldry 2001, Borg-Stein et al 2002, Gunn, 2007, Shah 2008).  2.3.4  Perpetuating Factors and Types of Myofascial Pain  Main contributing factors of myofascial pain are direct or indirect trauma, exposure to cumulative and repetitive strain, overloading or overuse of muscle and postural dysfunction (Borg-Stein et al 2002, Wheeler 2001). When myofascial pain is due to these mechanical causes it is called “primary myofascial pain”. Common primary myofascial pain syndromes include myogenic (tension-type) headache, neck pain, shoulder pain, low back pain, piriformis syndrome, leg pain, knee pain and ankle pain (Gunn 1997, Baldry 2001, Gerwin 2001).  Other non-mechanical causes such as chronic infection, visceral diseases, peripheral neuropathy (nerve lesion or dysfunction in peripheral nervous system), compression of nerve root (radiculopathy) and vitamin deficiency are responsible for the development of “secondary myofascial pain” because myofascial pain often occurs in conjunction with other conditions (Backonja et al 1998). Examples of secondary myofascial pain include temporomandibular joint dysfunction, carpal tunnel syndrome, impingement syndrome, rotator cuff tear, visceral pain syndromes, radicular pain, complex regional pain syndrome and spondylosis (Gerwin 2001).  2.3.5  Pathophysiology  Pathophysiology of myofascial pain has been described in books such as “Myofascial pain and dysfunction: the trigger point manual” (Simons et al 1999), “Muscle pain: understanding its nature, diagnosis and treatment” (Mense et al 2001) and “Myofascial pain and fibromyalgia syndromes: a clinical guide to diagnosis and management” (Baldry  8  2001). Below gives summaries regarding the pathophysiology of primary and secondary myofascial pain.  2.3.5.1  Primary Myofascial Pain  Research investigating myofascial pain shows that direct injury and mechanical stress on muscle are primary causes for myofascial pain (Baldry 2001). Trauma or abnormal stress causes affected muscle fibers to release intracellular calcium excessively. This abnormal increase of calcium induces uncontrolled muscle fibers shortening (contracted) activity, local circulation impairment and increased metabolism, resulting in the formation of muscle contracture or taut band and the activation of TrP (Hong et al 1998). These muscle tension abnormalities cause local ischemia and the shortened muscles release endogenous substances such as bradykinin, prostaglandins and serotonin. These endogenous substances are muscle nociceptor activating substances which activate muscle nociceptors and subsequently cause deep muscle aching pain, muscle tenderness, muscle weakness and decrease range of motions (Mense 2003, Mense et al 2001, Galluzzi 2007). Furthermore, sensitized muscle nociceptor endings release neuropeptides such as substance P and calcitonin gene-related peptide (CGRP) which lead to a cascade of events including the release of histamine, bradykinin, prostaglandins and serotonin. This cumulative effect creates local edema in muscle tissue (Shah 2008). Furthermore, this rapid and intense discharge of sensory fibers (sensory afferent barrage) activate sympathetic preganglionic neurons on reaching the spinal cord and thus causes noradrenergic postganglionic neurons in sympathetic chain become activated. As a result, sympathetic efferent activity is being increased and causes the release of norepinephrine which is responsible for the autonomic phenomena (Jay 1995, Baldry 2001). Besides, studies show that activation of sympathetic preganglionic neurons is responsible for pain generation (Janig 1995, Janig et al 2001, 2003) and may directly involves inflammatory pain through secretion of nerve growth factor (NGF) driving local inflammation (Andreev at al 1995, Woolf et al 1996).  Apart from peripheral muscle nociceptor sensitization, central sensitization at spinal cord 9  dorsal horn may also responsible for myofascial pain mechanism (Hong et al 1998). When peripheral nociceptors are sensitized by injured muscle as described above, the high-threshold Group IV (C) afferents will fire at lower threshold. This lowering of the activation threshold fires more readily and thus induces central sensitization at dorsal horn (Hoheisel et al 1993). This neuroplastic change causes allyodnia and also induces deep somatic afferents ramify and converge at synaptic connections with post-synaptic (second-order) neurons at dorsal horn. And this explains the phenomenon of referred pain to adjacent muscles due to the expansion of receptive field (Vecchiet et al 1999, Bahr et al 1981). Central sensitization can also activate the release of substance P and N-methyl-D-aspartate (NMDA) channel which further enhances the synaptic connections at dorsal horn. This may account for the persistent pain when TrP is once activated (Shah 2008).  2.3.5.2  Secondary Myofascial pain  Myofascial pain can also be secondary to visceral diseases because visceral afferent synapse and somatic afferents both terminate at Lamina I and V at specific segment of spinal cord. This dual innervation results in convergence of somatic and visceral input (Stephen 2006). Therefore, nociceptive input from internal organs appears to augment the excitation of transmission neurons primarily concerned with receiving inputs from muscle nociceptors and sensitizes muscle efferent fibers, causing pain and tenderness perceived in muscles associated with the affected visceral organs (Baldry 2001, Graven-Nielsen 2006).  Other causes of peripheral neuropathy, such as nerve compression, chronic infections, and tumor may cause nerve lesion or dysfunction which is also responsible for the development of secondary myofascial pain (Backonja 2003, Backonja et al 1998, Dworkin 2002, Hansson et al 2001, Latov 2007, Wheeler 2004). Nerve lesion or dysfunction causes hypersensitivity in striated muscle of neuropathic origin (i.e. peripheral neuropathic pain) which triggers activation of TrP and subsequently the pathological mechanism of myofascial pain (Gerwin 2001). We will see below that  10  intramuscular stimulation (IMS) bases its intervention strategy on a pathophysiological model that considers most chronic myofascial pain syndromes to be secondary to the compression of nerve roots (Gerwin 2001, Gunn 1997).  2.3.6  Treatments  Treatments for myofascial pain are diverse. Conventional systemic treatment for myofascial pain includes non-steroid anti-inflammatory drugs (NSAIDs), opioid, antidepressants, anticonvulsants, muscle relaxants (Wheeler 2004, Borg-Stein et al 2002). However, because of limited long-term efficacy and safety of conventional treatments, alternative treatments such as dry needling (including acupuncture and intramuscular stimulation (IMS)), transcutaneous electrical nerve stimulation (TENS), low level laser therapy (LLLT), massage and exercises are also widely used to treat chronic myofascial pain patients (Baldry 2002, Cummings 2007, Han et al 1997).  2.3.6.1  Conventional systemic treatment  2.3.6.1.1 Oral medication Non-steroid anti-inflammatory drugs (NSAIDs) such as ibuprofen, indomethacin and diclofenac are commonly used as first line medications in treating mild myofascial pain patients because of the safety and low cost (Yap 2007). A recent review of evidence from American Pain Society stated that NSAIDs when compared to placebo showed significant difference in alleviating chronic low back pain a week after treatment (Chou et al 2007). However, long term use of NSAIDs is not recommended due to frequent occurrence of renal and gastrointestinal adverse effects (Wheeler et al 1995, Argoff et al 1998). Common muscle relaxants for myofascial pain include cyclobenzaprine, carisoprodol, methocarbamol, chlorzoxazone, metaxalone and tizanidine (Wheeler2004). Clinical trials have demonstrated that patients with acute neck and low back disorders had a significant decrease of muscle spasm severity and pain levels (Abrus et al 1990, Berry et al 1988, Fryda-Kaurimsky et al 1981) but evidence for chronic myofasical pain is still limited (Moulin 2001, Aker et al 1996). Adverse effects such as sedation and muscle weakness  11  are observed (Wheeler2004). Antidepressants such as amitriptyline and despiramine are found to be effective in particular for chronic tension-type headache and back pain (Argoff et al 1998, Bendtsen et al 2000, Brown et al 1978). A systematic review of antidepressants against placebo for chronic back pain (9 trials) found a standardized mean difference (SMD, difference in means divided by a standard deviation) of 0.41 (CI, 0.22-0.61) for pain relief (Salerno et al 2002). Adverse events associated with antidepressants include sleep disturbance, cardiac conduction block, dizziness, constipation and sexual dysfunction (Settle 1998). Anticonvulsant is a common type of neuropathic analgesics which treat neuropathic pain. As secondary myofascial pain is usually induced by peripheral neuropathy, anticonvulsants such as gabapentin, venlafaxine and benzodiazepines are also used in treating myofascial pain patients. A Cochrane review (2 high-quality trials) found tetrazepam to be associated with a greater likelihood of pain relief (RR, 0.71 [CI, 0.54-0.93]) and global improvement (RR, 0.63 [CI, 0.42-0.97]) compared to placebo in treating chronic low back pain, after 10 to 14 days (Cochrane Back Review Group 2003). Side effects of anticonvulsants reported include depression, drowsiness, dizziness, constipation nausea and ataxia (Wiffen et al 2005). Opioids like tramadol are commonly used for treating severe myofascial pain especially in lower back (Bord-Stein et al 2002). A Cochrane review of opioids (3 high quality trials) showed that tramadol was more effective than placebo to relieve chronic low back pain with SMD 0.71 (95% CI 0.39-1.02) and improve function, SMD 0.17 (95% CI 0.04-0.30) (Deshpande et al 2007). Beside severe constipation, long term usage of opioids may lead to the development of aberrant behaviour such as drug abuse and addiction (Argoff et al 1998) and can contribute to prolonged work disability (Henderson 1991, Swartz et al 2000).  2.3.6.1.2 Therapeutic Trigger Point Injection Therapeutic trigger point injections have also been used empirically in myofascial pain  12  patients. The injections are directed at TrP within the target muscle to block or inhibit afferent and efferent neural pathways to induce muscular elongation, and thus reduce the pain (Wheeler 2004). Common types of TrP injections include local anesthetic and botulinum toxin (Baldry 2002, Borg-Stein et al 2002, Wheeler 2004).  Local Anesthetic Trigger Point Injection It has been common practice to inject local anesthetic into TrP to decrease pain. Common local anesthetics used include bupivacaine, lidocaine, mepivacaine, procaine and etidocaine (Wheeler 2004). Local anesthetics are compounds that, when applied to nerve tissue, produce a reversible loss of sensation.  They interfere with the conduction  process of nervous tissue by preventing the voltage dependent increase in sodium conductance and thus, block the initiation and propagation of action potentials (Catterall 1987).  Double blind RCTs have shown that the effect of local anesthetics were not  superior to that of saline. Tschopp (1996) in a study of 107 patients showed that there was no significant difference among groups receiving bupivacaine 0.25% (% of residual pain: 21.3 ± 6.3 %), lignocaine 1% (33.1 ± 5.7 %) or saline 0.9% (28.8 ± 5.8 %) with respect to reduction of pain after 1-week follow-up. Similarly, in a 4-day trial of 53 patients, Frost (1980) showed that mepivacaine 0.5% injection (75% improved) did not provide any benefit over saline injection (68% improved) in reducing pain. Two other high quality trials showed that dry needling and local anesthetic injections had comparable effects in reducing pain. In a trial (n=30), McMillan (1997) showed that pain intensity and unpleasantness scores decreased significantly at the end of treatment in all groups (I: procaine + simulated dry needling; II: dry needling + simulated local anesthetic; III: simulated local anesthetic + simulated dry needling). There were no statistically significant between-group differences in pain pressure thresholds and pain scores after 3 weeks of treatment (VAS I: baseline=39±24 follow-up=28±32; II: baseline=37±18 follow-up=25±25. III: baseline=34±25 follow-up=19±20). Garvey (1989) found in a trial (n=63) comparing 4 groups (I: lidocaine 1%; II: lidocaine 1% + corticosteroid; III: dry needling; IV: acupressure + vapour coolant spray), there was no significant pain relief difference among the groups at 2-weeks follow-up (I: 31% improved; II: 36% improved; III: 55% improved; IV: 50% improved). Most of these trials are underpowered to show  13  any effect and of poor quality; despite these two limitations, it seems that the effect of injecting local anesthetic does not improve much when compared to dry needling which treats the same TrP.  Botulinum Toxin Trigger Point Injection Botulinum toxin is a potent neurotoxin which causes flaccid muscle paralysis by blocking acetylcholine (a chemical that causes muscle contraction) release at the neuromuscular junction (Ho et al 2007). A systematic review included 5 studies comparing botulinum toxin A and saline injection where 4 trials (n=246) showed insignificant difference between both groups in reducing myofascial pain while 1 study (n=26) found that botulinum toxin A group (change in VAS=-2) had greater reduction in pain when compared to saline group (change in VAS=1.5) in 4 weeks (Ho et al 2007). A small trial (n=18) showed that botulinum toxin A (decrease in VAS = 2.705 ± 3.31) and bupivacaine 0.5% (decrease in VAS = 2.0 ± 2.03) had equivalent effect in reducing pain in MPS (Graboski et al 2005). The above clinical trials are characterized by small sample size and poor quality. They show that trigger point injections, regardless the types of drugs, had benefits in reducing myofascial pain but are not superior to that of saline injection and dry needling (Tschopp 1996, McMillan 1997, Garvey 1989, Graboski et al 2005, Porta 2000). “Needling effect” appears to be the key factor to reduce the pain and this would explain why all patients show a significant pain reduction after treatment – with or without injection and whatever the injection is. Overall, conventional drugs injections have been shown to have a short-term positive effect in alleviating myofascial pain. However, (a) long-term efficacy of these drugs remains unclear and (b) the effect seem to be similar of what is observed with simple dry needling. Adverse events reported in therapeutic injection therapy included dizziness, nervousness, insomnia, regional weakness, soreness and dry mouth (Dreyer 2000).  14  2.3.6.2  Alternative Treatments  2.3.6.2.1 Exercises Stretching exercises serve as the basis of exercise treatment of myofascial pain because daily stretching muscles address the release of muscle tightness and shortening and thus permit gradual restoration of normal activity (Borg-Stein et al 2002). Other forms of exercises like strengthening exercises (repetitions of specific muscle contraction) and aerobic exercises (such as walking and cycling) are also recommended in rehabilitation program to prevent overloading muscles and recurrence of myofascial pain (Graff-Radford et al 1987). A controlled study of 20 patients with chronic myofascial pain in temporomandibular region showed that active and passive jaw movement exercises and correction of body posture were useful in reducing pain and increasing range of motion (Nicolakis et al 2002). Meta-analysis of a Cochrane review (23 trials of chronic pain patients out of 43 trials) showed that the pooled weighted mean improvement was 10.2 (95% CI: 1.31 to 19.09) for exercise therapy compared to no treatment, and 5.93 (95% CI: 2.21 to 9.65) compared to other conservative treatments (van Tulder et al 2000). However, most of the trials were low in quality due to inadequate blinding.  2.3.6.2.2 Massage Massage is a soft tissue manipulation using hands with pressure on any part of body. There are many different kinds of massage, for instance, deep tissue or trigger point massage applies pressure on taut band creating reflex relaxation; Swedish massage uses strokes flowing on the body which creates deep circular movement, friction and vibration to reduce muscle stiffness and promote blood circulation (NCCAM 2009). Massage is thought to offer symptomatic relief of pain through physical and mental relaxation (Ernst 1999). The manipulations and pressure of massage may break down subcutaneous adhesions and prevent fibrosis and promote circulation of blood and lymph (Donnelly et al 2002) Research has suggested that massage stimulation might help to block pain signals sent to the brain (Melzack et al 1965). It is also suggested that massage might stimulate parasympathetic activity which promote reduction of anxiety and depression and autonomic dysfunction including odema (Field 1998, Ferrell-Tony et al 1993). A  15  systematic review (5 trials with chronic low back pain) showed the possible benefits of massage therapy in relieving chronic low back pain (Furlan AD et al 2008). Meta-analysis was not available in the review due to heterogeneity across trials in terms of difference in comparative treatments and outcome measurements. One large study with long term follow-up (n=172; Cherkin 2001) showed that, taut band or TrP massage was superior to acupuncture in its effect on pain (symptoms scale 3.08 vs 4.74, p = 0.002) and function (dysfunction scale 6.29 vs 8.21, p = 0.05) at 52 weeks after randomization. Another large study (n=100; Geisser 2005) showed that massage therapy for myofascial pain (muscle energy technique that promotes muscle relaxation by activating the golgi organ reflex) combined with exercises appears to be beneficial in treating chronic low-back pain when compared to sham massage (no muscle energy technique) plus exercises (change in VAS score was -2.05 vs -0.38). Although massage was found to be beneficial in treating chronic low back pain in this review, most of the trials were prone to biases because of the lack of blinding and unclear concealment of allocation (Furlan AD et al 2008).  2.3.6.2.3 TENS and LLLT Transcutaneous electrical nerve stimulation (TENS) and low level laser therapy (LLLT) are both non-invasive and safe devices for treating myofascial pain. TENS is an electrical stimulation applied on surface of skin to relieve pain. Stimulation parameters for TENS vary from trial to trial. In general, high frequency (40-150Hz), low intensity current amplitude (10-30mA) and short pulse duration (50 microseconds) are usually enough to produce a motor contraction (Sluka et al 2003, eMedicine 2007). The effect of TENS in relieving pain is still controversial. For instance, in chronic low back pain, a Cochrane review (2 trials) showed contradictory results: positive in one study but no effect in the other (Khadilkar et al 2005). For chronic neck pain, a randomized controlled trial (n=280; Chiu et al 2005) showed that TENS was more effective in relieving pain than placebo but not superior to exercises (change in NRS TENS: 0.38±0.60; exercises: 0.39±0.62; control: 0.23±0.63).  16  LLLT is a red or infra red beam laser with wavelength from 632nm-904nm and power from 15mW to 100mW (Mester et al 1985, Emshoff et al 2008). A Cochrane review included 4 trials with chronic low back pain patients (Yousefi-Nooraie et al 2008). Of which two studies (n=61; Djavid 2007 , Klein 1990) comparing LLLT plus exercises versus sham laser plus exercises showed a pooled result of weighted mean difference (WMD) was -6.38 in pain relief (95%CI: -15.68 to 2.91) at short-term follow-up (Yousefi-Nooraie et al 2008). Another study in the review (n=71; Soriano 1998) showed that LLLT (44.7% of patients had excellent pain relief) was superior to sham laser (15.2%) in relieving chronic low back pain at 6 months follow-up. A recent double-blind randomized controlled trial (Gur A et al 2004) of 60 chronic myofascial neck pain patients, the improvement of pain in LLLT (63% of patient had pain relief) is statistically better than that in placebo group (19%).  2.3.6.2.4  Dry Needling  Dry needling is the use of solid and fine needle for therapy. In pain management, needles are deeply inserted into muscles to alleviate pain. There are two main types of dry needling techniques to treat chronic myofascial pain. One is traditional Chinese acupuncture which targets at points of meridians. Another type is dry needling of trigger point which targets at points of palpable tenderness in contracted muscle. Dry needling of TrP can be further divided into two techniques: Ah-Shi acupuncture and intramuscular stimulation (IMS).  Traditional Chinese acupuncture is a dry needling technique that targets on classic acupuncture points which emphasize a smooth flow of Qi (vital energy) and homeostasis in human body. It has been practiced in China for thousands of years in reducing chronic pain and started to draw attention to western countries in the past decades. Classic acupuncture points or acupoints are points located along meridians of energy which connect organs and different parts of body. While another class of acupuncture, Ah-Shi acupuncture, targets Ah-Shi points which are defined as points of palpable tenderness located in muscle contracture where the definition corresponds to TrP (Birch 2003, Hong 2000, Shah 2008, Mense et al 2001). Ah-Shi acupuncture is thus a technique of TrP dry 17  needling. Intramuscular stimulation (IMS), similar to Ah-Shi acupuncture, is a form of dry needling technique that specifically targets myofascial TrP. It is a standardized technique which has its unique treatment strategy and theory behind (Gunn 2007). IMS theory is based on the fact that TrP and taut band at limbs and trunk are closely associated with the segmental distribution of lumbar radiculopathy at the back (Gunn 1997). It is believed that any nerve root lesion or dysfunction (peripheral neuropathy) at spine levels will lead to hypersensitive to the innervated striated muscle of neuropathic origin, creating taut band and myofascial pain (Cannon et al 1949). According to this vision, IMS model assumes chronic myofasical pain is mostly secondary to initial peripheral neuropathic lesion (i.e. radiculopathy in most instances). Therefore, IMS is a broader approach of TrP needling when compared to Ah-Shi acupuncture. IMS targets not only contracted limb and trunk muscles, but also the associated segments of paraspinal muscles (semispinalis, rotators, multifidus and spinalis) at spine levels with the objective to remove the source of pain (Gunn 1989, Gunn 1997) (Appendix A). This theory is interesting, but it has never been documented by any experiments. Several hypotheses of dry needling mechanism have been suggested. First of all, recent studies proposed that inserting needles into TrP might create a local twitch response (LTR) that evokes transient contractions of muscle fibers and sensitizes reflex motor efferent activity or golgi organs (proprioceptive sensory receptor organ that measures tension of muscle contraction and causes reflex reaction) causing muscle relaxation to occur (Baldry 2001, Longhurst 2004). By removing muscle contraction, excessive release of calcium and endogenous substances in muscles may be terminated, and subsequently discontinue the peripheral sensitization (Shah 2008). Because of the high spatial correspondence between classic acupuncture points and TrP (Melzack 1977), needling at acupuncture points might also produces LTR where scholars regarded this phenomenon as “De Qi”. In addition, recent animal studies documented that acupuncture needles activate proprioceptive Aβfibers which inhibit the input of small nociceptive C fibers according to Gate Control Theory (Moffet 2006, Abram 2006). Besides, studies also proposed that  18  needle insertion may stimulate Aδfibers which causes interneuron activation in the dorsal horn and the release of endogenous opioids and neurotransmitters (serotonine, gama-aminobutyric acid and acetylcholine), inhibiting intra-spinal transmission of C fiber input (Cheung et al 2001, Moffet 2006). Another hypothesis is that acupuncture can modulate the sympathetic outflow and reduce the sympathoexcitatory reflex response (Li et al 1998, 2001, Dai et al 1992, Tjen-A-Looi et al 2003) with decrease of the inflammatory reaction and subsequently pain (Longhurst 2004). Some studies also hypothesized that acupuncture can influence electromagnetic field in the body and thus alter the chemical neurotransimitters which inhibit central sensitization, reversing neuroplasticity in the nervous system (Audette et al 2004, Shupak et al 2004). Studies have been carried out for evaluating the effect of dry needling in treating chronic myofascial pain has been identified. For traditional acupuncture, studies applied needles at classic acupuncture points mainly on meridians BL, GB and KI with insertion varied from 0.5 to 2 inches. A Cochrane systematic review (Furlan et al 2005) gave evidence supporting the short-term (3 months or less) pain relief and functional improvement of acupuncture in chronic low back pain patients, compared to no treatment or sham therapy. In the review, the pooled analysis of two low quality trials (Coan et al 1980, Thomas et al 1994) showed that acupuncture was more effective than no treatment for short term pain relief, with a standardized mean difference (SMD: mean difference divided by standard deviation) -0.73 (95% CI: -1.19, -0.28). Acupuncture was also shown to be more effective than sham therapy in terms of short term pain relief, with a weighted mean difference (WMD: sum of the differences weighted by individual variances) -1.78 (95% CI: -2.55, -1.07) from two high quality trials (Carlsson et al 2001, Molsberger et al 2002). However, results for intermediate-term (3 months to 1 year) pain relief did not show acupuncture was better than sham therapy. A pooled result from two high quality trials (Carlsson et al 2001, Leibing et al 2002) found that acupuncture was not significantly better than sham therapy in terms of intermediate-term pain relief, with a WMD -0.57 (95% CI: -1.47 to 0.33). Similar result was obtained from two recent large studies by Haake et al (2007) and Brinkhaus et al (2006). Haake et al (2007) showed that the mean difference between acupuncture and sham (needling at non-acupoints) was -3.4 (95% CI:  19  -10.3, 3.7) at 6-months follow-up. While Brinkhaus et al (2006) found the mean difference between acupuncture and superficial needling was -0.6 (95% CI: -1.4, 0.3) at 12-months follow-up. Both studies showed no significant difference in pain relief between acupuncture and sham acupuncture in intermediate term. For dry needling of TrP or Ah-Shi acupuncture, six trials were identified and needles were inserted approximately 0.5-1 inch into trigger points according to different trials. Most of them were of poor methodological quality and limited to small sample size. In a trial of 30 patients with chronic myofascial pain in jaw muscles, McMillan (1997) showed that pain intensity and unpleasantness scores decreased significantly at the end of treatment in all groups (procaine 1% vs dry needling vs sham dry needling). However, there was no statistically significant between-group difference in pain scores after 3 weeks of treatment. One trial showed that the effect of TrP needling and sham laser acupuncture in alleviating chronic neck pain were comparable immediately after treatment (Irnich et al 2002) with mean difference of 1.7 (95% CI: 1.0, 2.5). Another chronic pain study (Itoh et al 2007) found that TrP needling was superior to sham needling at 13-week follow-up. Ga & Choi et al (2007) showed that acupuncture had comparable effects to 0.5% lidocaine injection at 1-month follow-up in elderly MPS patients in upper trapezius muscle. Different results were found in 2 other studies. A trial of 29 patients with chronic cervical, back or shoulder MPS by Kamanli (2005) showed that 0.5% lidocaine or botulinum toxin A were more effective in reducing pain than dry needling at 1 month follow-up. Another trial without blinding patients (Hong 1994) also showed that lidocaine 0.5% injection had a greater pain relief at 2 weeks after treatment when compared to dry needling. The two chronic neck pain studies as described above also compared the effect of alleviating chronic pain between classic acupuncture and dry needling of TrP. However, the results were controversial (Irnich et al 2002, Itoh et al 2007).  Two studies were identified for the evaluation of IMS. Needles were inserted about 1-2 inches into muscle of taut bands and paraspinal muscles at the associated spinal segments. Both of them were of low quality. Ga & Koh et al (2007) showed that among 43 patients  20  with chronic myofascial pain in upper trapezius muscle, IMS was equivalent in reducing pain intensity to lidocaine 0.5% injection at 1-month follow-up. Another study by Gunn (1980) involved 53 patients with chronic low back pain without blinding patients. Both groups followed a standard regimen of physiotherapy, remedial exercises and occupational therapy while subjects in treatment groups also received IMS twice a week. In the IMS treatment group 62% of patients returned to their original work and 34% shifted to a lighter employment while in the control group only 15% of patients returned to their original work and half of these worked in a lighter employment.  All in all, among these dry needling techniques, more RCTs were conducted assessing the effect of traditional Chinese acupuncture when compared to the other two. The existing evidence shows that acupuncture is better than sham therapy in reducing chronic low back pain only in the short-term, there is not enough evidence showing acupuncture is superior to sham regarding intermediate and long-term benefits. For dry needling of TrP, trials were mainly small in size and with poor methodological quality. It seemed that dry needling exhibited similar effect in alleviating chronic myofascial pain compared to anesthetic injections (Cummings et al 2001), but the effect of TrP needling over sham needling was not well documented. We found two studies comparing classic acupuncture and TrP needling techniques with controversial results. Regarding IMS, although the two identified studies showed favourable outcomes towards IMS, they were of poor quality and small sample size. Despite the lack of solid evidence, the IMS technique has been used widely: hundreds of practitioners have been trained and practice worldwide. Testimonials and donations from patients speak to the positive effects of IMS but no solid clinical evidence is currently available supporting the effect.  21  CHAPTER 3: Rationale, Objectives and Hypothesis 3.1  Rationale  Although there are different kinds of treatments available for myofascial pain, chronic myofascial pain patients are still under-treated (Breivik 2006, Robinson 2007). A survey done by the American Pain Society in 1999 revealed that more than four out of ten people suffering moderate to severe pain were unable to find adequate pain relief (American Pain Society 1999). In this context, complementary and alternative treatments (CAM) are frequently used by patients. It is therefore important to evaluate the effect of alternative treatments so as to better inform the public regarding their safety and effectiveness in alleviating chronic pain. Among a large range of alternative treatments, Intramuscular Stimulation (IMS) lacks solid clinical evidence and seems interesting. This is why my thesis focused on the evaluation of IMS technique in improving chronic myofascial pain. The randomized controlled trial (RCT) is the gold standard for assessing the efficacy of a treatment. However, several observational studies have to be conducted before to assess whether there is a treatment effect and the associated effect size so as to better calculate the sample size needed for the RCT. Also, these studies are useful to standardize data collection in order to reduce any recording bias. Furthermore, before conducting a multi-practitioners study, it is important to standardize the practice and to ensure all practitioners involved examine and treat patients in the same way. With these objectives in mind, preliminary studies including two chart reviews and one inter-rater-reliability test have been conducted in the preparatory phase of setting up a RCT to evaluate the effect of IMS.  3.2  Objectives and Hypothesis  General Objective: The thesis’ goal was conducting three preliminary studies to generate useful information that would help deciding to conduct (or not) a RCT and designing this trial.  Each study  has specific objectives and hypotheses.  22  Study 1: First Chart Review The overall objective of this study was to gather useful information regarding the effectiveness of IMS to justify the conduct of RCT. Specific objectives were 1) to describe the patients’ population at one IMS clinic; 2) to document the IMS effect (decrease in pain) in treating chronic myofascial pain. We hypothesized that the success rate of IMS (pain intensity reduced by at least 1 unit on 0-10 point scale) would be at least 50% in patients with myofascial pain for 3 months or more.  Study 2: Second Chart Review Because of missing information during the first chart review, the clinic modified its chart recording process using standard forms. The overall objective of this second chart review was to gather useful information for the design of RCT to assess the effectiveness of IMS. Specific objectives were 1) to access the effect size of IMS in pain improvement; 2) to assess the effectiveness of IMS in improving disability, quality of life and to assess patients’ satisfaction towards treatment. We hypothesized that the success rate of pain improvement (pain intensity reduced by at least 1 unit 0-10 point scale) would be at least 50%.  Study 3: Inter-rater Reliability Test The primary objective of this study was to test the agreement among IMS practitioners in identifying number of tender taut bands in spinous muscles along the spine and in extremity muscles in different parts of body. Secondary objective was to test the consistency of IMS practitioners in identifying taut bands in each muscle and recording the signs of autonomic dysfunction. We hypothesized that the agreement in identifying number of tender taut bands in different regions would be at least 0.6 (Intra-class correlation coefficient) and the kappa values of identifying taut band in each muscle level would be at least 0.6.  23  CHAPTER 4: Study 1-Documentation of the Effect of Intramuscular Stimulation to Treat Chronic Myofascial Pain: A Chart Review 4.1  Introduction  With the objective to test the feasibility of conducting a randomized controlled trial (RCT) to assess the effect of Intramuscular Stimulation (IMS) in treating chronic pain a chart review was conducted in an IMS clinic in Vancouver to gather preliminary information regarding patients’ population characteristics and the treatment effect.  This information  is essential to the design of a RCT in terms of recruitment and sample size estimation.  4.2  Methods  4.2.1  Study Design  The design is observational. Chart review was conducted in two phases. Phase 1 was a systematic review of randomly selected patients’ charts at an IMS clinic in Vancouver. Phase 2 was a telephone interview of selected patients to gather their subjective opinion regarding long term effects and satisfaction of IMS treatment in alleviating their chronic pain.  4.2.2  Study Population  Patients who suffered from chronic (pain persisted at least 3 months) and received their first treatment between 1st January, 2006 and 31st December, 2006 at the clinic were eligible for the study regardless of their age, sex and regions of pain. Patients who had their pain that persisted less than 3 months at the time of first visit were excluded. A total of 213 patients were identified from the above criteria and 100 patients were then randomly selected for chart review using computer-generated random number. The same 100 patients were also invited to participate in the second phase of the study, a telephone interview.  4.2.3  Study Procedure  4.2.3.1  Chart Review  The selected 100 patient’ charts were reviewed systematically by the student. All necessary chart information including patients’ age, gender, regions of pain, pain onset, 24  number of treatments received, subjective reporting of their pain improvement after treatment, and practitioners’ comment on patients’ pain control were extracted using standard data extraction forms. Collected information was reviewed by the Principal Investigator to assess the quality of data collection.  4.2.3.2  Phone Interview  The same 100 patients were mailed a consent form with a covering letter and a pre-stamped reply envelope asking for their permissions of telephone interview. Telephone interviews were conducted within one week after the return of patients’ signed consent forms. All telephone interviews were carried out by the student. Interviews were done in a closed and quiet room to ensure confidentiality and interview quality. Interview content was based on a standardized questionnaire which contained 10 questions in relation to pain onset, pain complaint, IMS treatment period, pain control after IMS treatment, persistence of treatment effect, current pain status, overall satisfaction with the treatment, opinion towards IMS effect in comparison with other treatments and recommendation of IMS.  4.2.4  Ethics  The study proposal and related materials were approved by UBC Clinical Research Ethics Board on 8th May, 2008.  4.2.5  Statistical Analysis  Statistical analysis was descriptive and results are presented with 95% confidence intervals (95% CI).  The population treated at the clinic during the period along with  useful chart information such as pain onset, pain complaints, number of treatments received, degree of pain relief and satisfaction with treatment are described and presented either as means and standard deviations or as percentages. Telephone interview results are also described and presented the same way.  25  4.3  Results  4.3.1  Chart Review  4.3.1.1  Population Characteristics  The mean age of the 100 patients was 51.1 (sd = 12.1), most of them (32%) were aged between 41 and 60 with 45% female. 18% of the population had pain persisted for less than 1 year (at least 3 months), 15% had pain for 1-3 years, 19% had pain lasted for 4-9 years and 30% of patients had their pain for more than 9 years by the time they received the first IMS treatment. Of the 100 patients, 12% had one region of pain; 34% had two or three regions of pain, 46% suffered from four or five regions and 8% had more than five regions of pain. Nearly 80% of the patients had lower back pain as one of their pain complaints. Upper back contributed 48%, neck and shoulder pain were 61%, upper limbs were 25% and lower limbs were 30%.  4.3.1.2  Treatments  Eight different practitioners were responsible for the administration of IMS to these 100 patients. Treatments were usually done on a once or twice a week basis. Number of treatment sessions varied by individuals, ranged from 1 session to 89 sessions. On average, patients received 10 sessions of IMS treatments (95% CI= 7.6, 12.9) with a median of 6 sessions.  4.3.1.3  Practitioners’ Comment on Patients’ Pain Control  Among the 100 charts, 78 charts had records of patients’ pain control. Of these 78 available charts information, 74 charts (95%) reported improvements in pain by practitioners (Improvement included decreased pain intensity, pain frequency or increased range of motion). Among the 74 charts that showed improvements, 76% had lower back pain, 32% had upper back pain, 70% had neck and shoulder pain, 30% had upper limbs pain, 34% had lower limbs pain. 1 chart (1%) reported no improvement (low back pain) and 3 other charts (4%) reported worsening. Among these 3 charts, 1 had lower back pain; 1 had upper and lower back pain; 1 had lower back and lower limbs pain. Of the 74 improved cases, 42% had records of improvement by the end of second treatment, 25% had improvements after the third or fourth treatment and the rest started  26  to show improvements after five or more treatments.  4.3.1.4  Subjective Report of Pain Control from Patients  Among the 100 patients, 22 of them had filled out a simple questionnaire consisting of one question regarding pain control after receiving the treatments. Patients could choose “much better”, “somewhat better”, “same as before” or “worse” in answering the questionnaire. Of the 22 patients, 11 patients (50%) stated that they were “much better” after the treatments, 10 patients (45%) had chosen “somewhat better” and 1 patient (5%) reported his/her pain as “same as before” after receiving treatments. The answers of those 21 patients who had stated “much better” or “somewhat” better in their questionnaires were consistent with the charts recorded by practitioners. However, the report of the patient who stated his/her pain was “same as before” was found to be inconsistent with practitioners’ record which stated that he/she had improved. Session in which patients filled out the questionnaire ranged from forth to fifteenth.  4.3.2  Telephone Interview  4.3.2.1  Patients’ Response  Each of the 100 patients received a consent form inviting their participation in a phone interview but only 18 of them had their signed consents returned. Of these 18 patients, 6 patients were unreachable after 5 attempts of telephone contact. Therefore, only a total of 12 patients (response rate =12%) were successfully involved in phone interviews.  4.3.2.2  Sample Characteristics  In these 12 patients, 8 (67%) had pain for 1 to 4 years while 4 (33%) had pain for over 6 years. All except one had their pain interfere their daily activities. Lower back pain complaints were found in 10 (83%) patients, 2 (17%) had upper back pain, 2 (17%) had neck pain, 3 (25%) had shoulder pain, 1 (8%) had upper limbs pain and 3 (25%) had lower limbs pain.  4.3.2.3  Current Pain Status  Among the 12 respondents, only 1 (8%) had no pain at the time of interview. 6 of them  27  (50%) had light pain, 4 (33%) had moderate pain and 1 (8%) still suffered from severe pain at the time of interview.  4.3.2.4  Treatment Effect  Of the 12 respondents, 6 (50%) commented their pain was greatly alleviated and the IMS treatment effect was persistent. 1 (8%) commented that though the pain was greatly alleviated, the treatment effect was importantly decreasing with time. 3 (25%) of them claimed that their pain was partly alleviated. 1 (8%) reported pain was slightly alleviated after treatment and 1 (8%) found that the pain did not change. These results were consistent with what we found in the charts except for the case that reported no change. In his/her chart, practitioner recorded the pain had decreased and the patient reported “somewhat better” on the clinic questionnaire at his/her fourteenth visit.  4.3.2.5  Satisfaction and Recommendation  Among the 12 feedbacks from patients, 8 (67%) were highly satisfied with the IMS treatment and would recommend it to other chronic pain patients. 3 respondents (25%) were satisfied with the treatment and would recommend others to try the treatment but not to expect perfect results. One patient (8%) was not satisfied by the treatment and would not recommend it to others.  4.3.2.6  IMS in Comparison to Other Treatments  Comparing to other ways of controlling pain that respondents had tried on, including physiotherapy, chiropractics, acupuncture, injections and drugs, 7 out of the 12 patients (58%) found that IMS was much better than what they had tried. One patient (8%) found that IMS might be better than other treatments. 3 respondents (25%) suggested that it was not better and 1 (8%) found that IMS was worse when compared to other treatments.  4.4  Discussion  From chart review, we found that the population treated at IMS clinic was aged from 41 to 60. We also observed that a majority of patients (30%) had their pain for 10 or more years which corresponds to the fact that (a) many patients remain under-treated with  28  currently accessible treatments (American Pain Society 1999) and (b) they consider alternative treatments after several years of pain. Besides, we found that most patients suffered from multi-area pain complaints where 80% had lower back pain as one of their pain complaints. This was consistent with epidemiological studies which showed that low back pain was one of the most prevalent chronic pain syndromes (Andersson 1999) and was found to be greatly associated with myofascial pain (Simons 1988, Weiner 2006). Regarding the IMS treatment effect, we found report of improvement in 95% of the 78 charts that contained IMS practitioners’ records; only 3% of patients got worse. This very high success rate of a treatment, however, should be interpreted cautiously because 22% of the data is missing and they correspond to practitioners’ subjective diagnosis. If we consider that the 22 subjects’ missing information was all from subjects who did not improve, the success rate would be 74% (a conservative estimate) which is still high, considering the pain chronicity. We also found personal comment in charts from 22 patients on pain improvement after receiving IMS treatment. Although results were good with 11 (50%) got much better, 10 (45%) were somewhat better and 1 (5%) had the same pain as before, the sample size is too small and too selected to act as an evidence supporting the positive effect of IMS. Also, the patient who claimed that his/her pain was the same as before on the questionnaire was marked on chart as “showing improvement” by practitioner. Therefore, the high success rate of IMS treatment as per practitioners’ reports carries some risks of positive interpretation bias. The telephone interview with patients to collecting subjective patients’ feedback on the effect of IMS independently to the IMS clinic to prevent the bias was disappointing because the response rate (12%) was very low. Several reasons may account for this low response rate. First, our study started in the year 2008 while the treatments were administered in the year 2006. Some patients had moved to other places as 11 (11%) envelopes were returned due to wrong address. It is also possible that patients might have forgotten their treatment experience in IMS clinic. Finally, patients might be unwilling to receive telephone interviews.  29  Of the 12 respondents, 7 (58%) found their pain was greatly alleviated after receiving IMS treatment, 4 (33%) had pain partly or slightly alleviated and only 1 (8%) found the pain did not change. In short, most of the patients involved in phone interview appreciated the IMS treatment and found that the treatment was at least partially effective in alleviating their chronic pain. Although telephone interview results were positive, the response rate is too low to conclude on the effect of IMS. Overall, the study gave a good picture of the patients’ population at IMS clinic. There were around 200 new patients with chronic pain every year at the IMS clinic. Most of them had low back pain, followed by neck and shoulder pain. So the recruitment of patients to participate in randomized controlled trial (RCT) should not be a problem. Regarding IMS treatment effect, the results from this study were positive showing good success rate of the treatment. However, the results were at high risk of bias due to lack of patients’ subjective comment from charts and low response rate from phone interview. The success rate from this study was considered not accurate for calculating the sample size for the RCT.  Because of these limitations, we did not compare our results to  published literature; this comparison is part of Chapter 5 (second chart review). In order to gather more reliable results, we suggested to modify the clinical forms used at the clinic and to implement a standardized questionnaire for patients to fill out during their visits. Routine standardized clinical recordings would minimize missing information and enable better evaluation of IMS treatment.  4.5  Conclusion  The result of this study did not give us enough information regarding the IMS effect in alleviating chronic myofascial pain. However, this study gave us a general picture of what kinds of patients were treated at IMS clinic and a preliminary idea about the effect of IMS. This information was useful to recommend changing the patient’s chart at the clinic to collect more systematically useful information, coming directly from the patients.  30  CHAPTER 5: Study 2-Documentation of the Effect of Intramuscular Stimulation to Treat Chronic Myofascial Pain: Second Chart Review  5.1  Introduction  In 2008, in the preparation phase of a randomized controlled trial (RCT), we conducted a chart review at one intramuscular stimulation (IMS) clinic in Vancouver with the objective to document the effectiveness of IMS in treating chronic myofascial pain (Chapter 3). This study had two important limitations: the chart recording process was not standardized and not consistent between practitioners, and the information was mostly recorded by the IMS practitioners, therefore prone to a “positive bias”.  Secondly,  our attempt to contact patients independently for telephone interview was not successful with low response rate. Because of these limitations, the IMS clinic decided to change its routine documentation practice and to collect clinical information in a more systematic way, using standard questionnaires. The clinical forms for recording clinical findings were standardized and all patients completed standard questionnaires at their first visit (baseline), their fourth visit (first follow-up) and eighth visit (second follow-up) to collect patients’ experience regarding pain, disability, quality of life and overall treatment satisfaction. The clinic implemented this new patient chart with standard recording on April 1st, 2009.  The second chart review has been carried out on February 1st, 2010  after 10 months of the new data collection process. The general objective of this study was the same as the first chart review; to determine the feasibility of conducting a RCT and make appropriate recommendations in the design of RCT if consider feasible. The primary clinical objective was to assess the success rate of IMS in reducing worst and average pain intensity. Secondary objective was to assess the effectiveness of IMS in improving degree of disability, quality of life and to assess patients’ satisfaction towards treatment.  5.2  Methods  5.2.1  Study Design and Sample Size  It is an observational historical cohort study. All chronic pain patients’ charts with their  31  first treatment received at the IMS clinic in Vancouver between April 1st 2009 and February 1st, 2010 were reviewed. Relevant information from the charts was extracted using standard forms and transferred to a database for statistical analysis. The target sample size for this study was the same as the first chart review: 100 subjects to have 80% power to detect a mean difference of 0.8 (SD=2.5) on a 0-10 point pain scale in Brief Pain Inventory (BPI) between baseline and follow-up in a two-sided paired t-test with alpha=0.05.  5.2.2  Study Population  Patients with chronic pain (pain that persists at least 3 months) and who had their first treatment received at the IMS clinic between April 1st 2009 and February 1st, 2010 regardless their age, sex and regions of pain were eligible for this study.  Patients with  pain persisting less than 3 months at the time of first visit were excluded.  5.2.3  Chart Review Process  Each chart was systematically reviewed by the student. All useful information including patients’ age, gender, region of pain, pain intensity, number of IMS treatments received, degree of disability, quality of life and treatment satisfaction, was extracted and recorded on standard forms; it was subsequently entered into a computer database. The Principal Investigator assessed the charts and database from time to time to ensure the quality of abstraction with the objective to reach a good level of accuracy.  5.2.4  Chart Information  Each chart consisted of an administrative form which contained basic demographic information (age, gender) and region of pain, and consisted of baseline and follow-up questionnaires. Baseline questionnaires were completed by patients on the day of their first IMS treatment. Follow-up questionnaires were completed at fourth and eighth treatment at the clinic. Baseline questionnaires included 5 questions of 0-10 point scales measuring pain intensity and the impact of pain on daily function from Brief Pain Inventory (BPI) and included 10 questions from Oswestry Low-Back Pain Disability Index (ODI). Similarly, follow-up questionnaires consisted of both questions from BPI  32  and ODI, as well as three questions of the Pain Treatment Satisfaction Scale (PTSS) adapted to measure satisfaction with intervention (Question 55 of PTSS) and the level of pain relief (Question 56 and 57) (Evans et al 2004). BPI is widely used to assess severity of pain (worst pain in last week, least pain in last week, average pain, pain right now) and the impact of pain on daily function (pain has interfered with your general activity, mood, normal work, relations with others, sleep and enjoyment of life). Questions regarding severity of pain and impact of pain that we adapted from BPI have been validated for reliability, consistency and sensitivity among low back pain patients (Cleeland et al 1994, Keller et al 2004). ODI consists of questions on activities of daily living which include personal care, lifting, walking, sitting, standing, sleeping, sex life, social life and traveling where an overall disability index can be computed (overall ODI score =  sum of scores obtained × 100% ): 0-20% minimal disability, 21-40% 5 × number of questions answered  moderate disability, 41-60% severe disability, 61-80% crippled (Fairbank et al 1980). It is one of the most commonly used questionnaires to assess degree of disability for back pain and has demonstrated good reliability, validity, and responsiveness (Fairbank et al 1980, Kumar et al 2007, Turk et al 2001). PTSS has been validated for both acute and chronic pain patients’ satisfaction with the study intervention regarding pain control and improvement in quality of life (Evans et al 2004).  5.2.5  Outcomes  The primary outcome was percentage of “success” in terms of worst and average pain score on BPI – we kept two outcomes in this exploratory study because the choice between the two measures of chronic pain is still not clear in the literature. Success was defined as pain score reduction by at least one unit between follow-up and baseline because a change of 1 point on BPI scale is regarded as minimally clinically important changes (Dworkin et al 2008).  Secondary outcomes were the change in all BPI outcome  scores; change in overall ODI score and results (in percentage) from PTSS regarding treatment satisfaction between baseline and follow-up.  33  5.2.6  Practitioners  There were four certified IMS practitioners at the clinic responsible for treating the patients in this study.  5.2.7  Statistical Analysis  This study was descriptive. All results were presented with 95% confidence interval; when relevant, p-values were calculated (without adjustment for multiple testing). The primary analysis was based on all the available data. Success was presented in percentage with 95% confidence interval.  Continuous variables were presented as mean difference  with confidence interval; two-way paired t-test was applied for the change in BPI and ODI outcome scores.  Satisfaction towards IMS treatment from PTSS questions was  presented in percentage. A multivariate logistic regression was carried out to identify predictors of worst pain and average pain changes. Sensitivity analysis was implemented to present results in different scenarios of missing data at first follow-up: 1) Conservative estimation was performed for the primary outcome (success/failure) by assuming all the missing data was treatment failure; 2) Worst and best case imputation were done for mean changes in BPI and ODI scores by replacing missing values with complete information based on estimation from the mean and standard deviation of the deteriorated and improved cases respectively in available data; 3) Last observation carried forward (LOCF) was also performed assuming the responses were constant over time. Population characteristics of patients who did not complete questionnaires were presented and analyzed within the context of future trial development.  All statistics were performed  with SAS version 9.1 Windows, SAS Institute Inc., NC, USA.  5.2.8  Long Term Follow-up  Apart from collecting data from usual clinical practice, in early December 2009, follow-up questionnaires were mailed to patients who were lost to follow-up. However, among 55 letters that we sent out, we only received 2 respondents (response rate= 4%). Because of the extremely low response rate, it was not possible to interpret these results (not presented in this thesis).  34  5.2.9  Ethics  The study proposal and related materials were approved by UBC Clinical Research Ethics Board on October 7th, 2009.  5.3  Results  5.3.1  Population Identification and Follow-up  Figure 5.1 shows the patient flow chart. A total of 155 patients received their first treatment at the IMS clinic between April 1st 2009 and February 1st, 2010. Of which 15 patients were excluded because they had pain for less than 3 months (acute pain). 21 charts were not included in the study analysis because patients did not want to complete the questionnaires. The characteristics of these 21 patients are tabulated in Table 5.1. Finally, a total of 119 patients with baseline questionnaire were included in this study. Of these 119 patients, 55 (46%) did not complete their first follow-up questionnaire. Therefore, complete data at first follow-up was available for 64 patients (54%). And 15 patients (13%) completed the second follow-up questionnaire. Among the patients who did not complete follow-up questionnaires, the main reasons included leaving the clinic before reaching their follow-up sessions (1st: 32, 58%; 2nd: 17, 35%); censoring before reaching their fourth or eighth treatment session at the time of study ended (1st: 9, 16%; 2nd: 10, 20%); and refusal to complete questionnaires (1st: 14, 25%; 2nd: 22, 45%).  5.3.2  Population Characteristics  Table 5.2 shows the demographic characteristics of patients who were included in this study and patients who had completed the first and second follow-up. Of the 119 included patients, the mean age was 46.6 (sd=12.9), ranged from 16 to 77. Female represented 59% of the population. Most of patients had suffered from pain for 1-3 years (35%) while 23% had pain persisted for more than 10 years. The majority of pain complaints were in lower back (61%), followed by lower limbs (41%) and neck and shoulder pain (36%). The mean worst and average pain scores at baseline were 6.93 (sd=2.02) and 5.15 (sd=1.93) respectively. And the mean ODI was 30.41 (sd=18.90) which represented moderate disability. Similar results were found in patients who had completed the first follow-up.  35  5.3.3  Pain Intensity Change on Brief Pain Inventory (BPI)  Table 5.3 shows changes for worst and average pain at first and second follow-up using the available data. Regarding worst pain, among 64 patients who completed the first follow-up, 63% (95% CI: 51%, 75%) had pain improved by at least 1 point (success), 17% (95% CI: 8%, 26%) did not have change in pain score and 20% (95% CI: 10%, 30%) had pain deteriorated (score increased by 1 unit or more). Regarding average pain, 55% (95% CI: 43%, 67%) had pain improved and 28% (95% CI: 17%, 39%) had pain deteriorated. Assuming the missing data was all failure, our conservative estimation for the success of improvement was 34% (95% CI: 25%, 43%) and 30% (95% CI: 22%, 38%) for worst and average pain respectively. Changes regarding different pain scores on BPI based on available data are tabulated in Table 5.4. Among the 64 patients who completed the first follow-up questionnaires, the mean improvement was -1.09 (95% CI: -1.69, -0.50) and -0.86 (95% CI: -1.40, -0.32) in worst and average pain score respectively. At second follow-up, average reduction in worst and average pain score among the 15 patients were -2.33 (95% CI: -3.85, -0.81) and -1.93 (95% CI: -3.31, -0.55) respectively. Sensitivity analyses were tabulated in Table 5.5 (best case imputation), Table 5.6 (worst case imputation) and Table 5.7 (LOCF) respectively. If we assumed all the missing data were of improved cases, the worst and average pain score changes were -1.58 (95% CI: -1.96, -1.21) and -1.61 (95% CI: -1.97, -1.25) respectively. If the missing data were of deteriorated cases, the changes were 0.38 (95% CI: -0.082, 0.83) and 0.27 (95% CI: -0.11, 0.66) respectively. Assuming the scores were unchanged between baseline and follow-up, we found that mean improvement of worst and average pain were -0.59 (95% CI: -0.92, -0.26) and -0.47 (95% CI: -0.77, -0.16) respectively.  5.3.4  Disability and Quality of Life Items on Brief Pain Inventory (BPI)  Table 5.8 presents the results of change in disability and quality of life scores on BPI using available data. Improvement was observed in all the items at first and second follow-up. At first follow-up, the greatest mean improvement was enjoyment of life with mean change of -1.98 (95% CI: -2.80, -1.17), followed by normal work with mean  36  change of -1.89 (95% CI: -2.75, -1.03) and general activity with mean change of -1.80 (95% CI: -2.52, -1.08). The mean changes were -3.47 (95% CI: -4.76, -2.18), -3.40 (95% CI: -5.16, -1.64) and 2.40 (95% CI: -3.74, -1.06) for general activity, normal work and enjoyment of life respectively at second follow-up. Results from best case, worst case and LOCF imputation were tabulated in Table 5.9, Table 5.10 and Table 5.11 respectively.  5.3.5  Oswestry Low-Back Pain Disability Index (ODI)  Among the 119 eligible patients, 12 (10%) did not complete the ODI index because they did not have back related pain. Therefore, we had ODI data from 107 patients (90%) at baseline, 53 (45%) at first follow-up and 14 patients (12%) at second follow-up. Table 5.12 shows change in Oswestry Disability Index (ODI) obtained from available data. ODI showed an improvement of -4.15 (95% CI: -10.07, 1.77) at first follow-up and of -8.25 (95% CI: -13.2, -3.31) at second follow-up. Sensitivity analyses with different approaches were tabulated in Table 5.13.  5.3.6  Pain Treatment Satisfaction Scale (PTSS)  Results from PTSS are tabulated in Table 5.14. At first follow-up, we had available data from 56 out of 64 patients who had completed first follow-up. Among the 8 patients who did not complete PTSS, 3 had worst pain reduced; 3 did not have any change in worst pain; and 2 had worst pain increased. Of the 56 available data, most of the patients (n=24; 74%) agreed (including strongly and somewhat agree) that they were happy with the duration of pain relief provided by IMS. Most of them (n=46; 82%) found that they had better physical health and could perform daily activities more easily (n=37; 66%). Another 39 subjects (70% of the patients) found their mood had improved after treatment and 35 (63%) had more often leisure activities. Overall, only 6 patients (11%) disagreed with the statement that their health improved after IMS treatment. There were 20 patients (36%) highly satisfied with IMS treatment, 28 patients (50%) satisfied and 2 patients (4%) were not satisfied. Besides, 27 patients (48%) found that the level of pain relief by IMS exceeded their expectations whereas 13 patients (24%) thought IMS did not meet their expectations in terms of pain relief. At second follow-up, similar results were obtained. Most of patients (73%-94%) agreed with the effect of IMS in improving their pain and  37  health related items, except 1 or 2 patients (7 or 13%). And 13 patients (87%) were satisfied with IMS treatment.  5.3.7  Predictors for Improvement in Worst and Average Pain Score  Multiple logistic regression was performed using the available data at first follow-up to identify the predictors for worst pain and average pain improvement (improvement was defined as reduction of pain score by 1 unit or more on BPI; otherwise it was a failure). The logistic regression model was mainly exploratory, so p-values were not provided. Results for worst and average pain improvement are tabulated in Table 5.15 and Table 5.16 respectively. Odds ratio greater than one means the particular level has higher tendency to have an improvement when compared to the reference level. From the results, it seemed that initial pain score was associated with pain improvement. The higher the initial pain score, the greater the probability of pain improvement. Also, there seemed a practitioner effect.  Practitioner D seemed to have higher odds of pain improvement.  His/her patients have higher probability of improving pain when compared to those treated by other practitioners. Regarding other predictors (age, gender and pain duration), results were not consistent and thus, these predictors seemed not to be associated with pain improvement.  5.4  Discussion  In this study, with all the available date, we found that the success rate of IMS in improving worst and average pain (at least 1 unit reduction in pain score) after four IMS treatments was 63% (95% CI: 51%, 75%) and 55% (95% CI: 43%, 67%) respectively among 64 patients. At second follow-up, the improvement was 67% and 73% respectively among 15 patients. Our conservative analyses of success rate (assuming missing values were all unsuccessful cases) were 34% (95% CI: 25%, 43%) and 30% (95% CI: 22%, 38%) respectively for worst and average pain improvement. Considering the difficulty in treating chronic myofascial pain, this conservative success rate could be interesting to be considered, should it be confirmed in the long term. Also, among 119 patients with eligibility criteria treated at the clinic, 64 (54%) completed first follow-up assessment. Of which, 32 left the clinic before the fourth treatment and 14 did not want to  38  complete questionnaires. This population may not necessarily represent failure of IMS because we found positive comments from the practitioner in the chart.  Comments,  such as “doing better”, “good progress”, “decrease numbness”, “increased mobility” and “decreased pain” were found in 39 patient charts (71%) out of 55 missing information. If we consider these patients who left the clinic before first follow-up assessment were “success”, the success rates changed from 34% and 30% to 66% and 63% for worst and average pain respectively. Our estimation based on available data for mean improvement of worst and average pain were -1.09 (95% CI: -1.69, -0.50) and -0.86 (95% CI: -1.40, -0.32) respectively at first follow-up. And they were -2.33 (95% CI: -3.85, -0.81) and -1.93 (95% CI: -3.31, -0.55) respectively at second follow-up. Results from worst case imputation were not too bad, mean deterioration of worst and average pain were 0.38 (95% CI: -0.082, 0.83) and 0.27 (95% CI: -0.11, 0.66) respectively. Compared to other high quality acupuncture studies (Brinkhaus et al 2006, Leibing et al 2002, Molsberger et al 2002), the effect size for average pain improvement in our study is relatively smaller. The population in these trials are similar to the one treated at the IMS clinic: Patients with chronic low back pain for more than 6 months, with a mean age ranging from 48 to 54 and a proportion of female ranging from 42 to 64%. The mean pain duration was between 9.6 (sd=8.2) and 14.7 (11.0) years while the mean baseline pain intensity varied from 4.8 (sd=1.8) to 6.6 (sd=1.5) on a 10-cm Visual Analog Scale (VAS). None of these studies provided changes in worst pain score. These studies either used the last values carried forward or the intention to treat approach. In the acupuncture group, the within patient change in average pain score immediately after treatments (number of treatments were 12 in studies by Brinkhaus and Molsberger; 20 in Leibing’s study) varied from -2.1 (sd=2) to -3.0 (sd=1.8). For our study, the average change was -0.86 (sd=2.18) after four treatments and -1.93 (sd=2.49) after eight treatments. The smaller within patient mean difference observed in our study compared to the one observed in the acupuncture trials may be due to the difference in effectiveness between IMS and acupuncture. However, apart from a possibility of existing real difference between the  39  two techniques, we also need to consider the following explanations.  Patients treated by  IMS received less treatment sessions than those in acupuncture trials, which may be an important factor in treatment effect. Our results reflect the mean difference after 4 or 8 IMS treatments, while some patients received 12 or 20 treatments in the acupuncture studies. Because of the high cost of IMS treatments (CAD$100 for assessment and CAD$70 for successive treatments), it may happen that patients leave the clinic without receiving optimal treatments. Besides, our results are generated from usual clinical practice rather than from an experiment. Patients involved in clinical trials tend to show higher improvements in response due to the fact that they are being studied: Hawthorne effect (McCarney et al 2007): the classic difference between “efficacy” and “effectiveness”. Also, positive bias may occur in these studies as we did not know whether there were independent investigators in these trials. When we have practitioners who are likely to bias in favour of needling technique to carry out their own trials, positive bias may happen because practitioners’ expectations towards trial outcomes may influence patients’ responses in single blinding trials. Compare to drug trials of chronic low back pain patients, the mean difference we found using available data was comparable. Two studies compared the effect between administration of combination tablets of tramadol and acetaminophen and placebo tablets, the standardized mean difference (SMD, mean difference divided by standard deviation) was -1.01 (95% CI: -1.24, -0.79) and -0.54 (95% CI: -0.76, -0.31) respectively (Peloso et al 2004, Ruoff et al 2003). A Cochrane review of antidepressants against placebo (9 trials) found SMD of 0.41 (95% CI: 0.22-0.61) which favours effect of antidepressant while in our study, if we consider SMD from available data (1st follow-up: 0.39 [0.86/2.18], 2nd follow-up: 0.78 [1.93/2.49]), our results were comparable to drug trials. Our study also found that IMS had the effect of improvement on disability and quality of life outcomes at both first and second follow-up. Consistent finding was also obtained from Oswestry Disability Index (ODI) although the result was less important in magnitude. Regarding IMS treatment satisfaction, nearly 90% of patients were satisfied with the treatment. More than 60% were happy with the duration of pain relief and were  40  able to perform daily activities more easily. This positive result, however, are difficult to interpret given the short term follow-up at the clinic. Our logistic model showed that initial pain score seemed to be associated with pain improvement. The higher the pain score before treatment, the higher the tendency to report improvement after treatment. This result may be due to a “regression to mean” effect. Logistic regression also shows some important difference between practitioners. Such a “practitioner effect” cannot receive satisfactory explanation within the context of an observational study; however it raises the question of a possible difference in treatment administration among practitioners at the clinic. If real, the problem has to be resolved before conducting the randomized trial with more training and standardization of practice to ensure high consistency before implementing the study. Overall, this study showed positive results regarding IMS in relieving chronic pain and improving pain consequences in the short term. However, it has several important limitations. This study only shows the immediate treatment effect after four and eight IMS treatments without long-term follow-up. Also, some patients may leave the clinic even they still have pain because of the cost of treatment. It is then possible that some patients did not get the optimal number of treatment sessions to relieve their pain at the time of analysis. However, our results may reflect IMS effectiveness in controlling pain in reality. Besides, our results were generated from usual clinical practice without control group and are prone to selection bias due to the important attrition. Our primary analysis was based on available data and assumed the missing information was independent to either observed or unobserved outcomes. In practice, it is not always the case. Our missing information may be due to treatment effect. Patients may leave clinic before follow-up assessment because they are free of pain or they feel worse after treatment. Therefore, we did not draw any conclusion regarding IMS effect from this study, instead we performed several sensitivity analyses to present results in different scenarios of missing data including best, worst and unchanged case scenario.  41  5.5  Conclusion  This study showed positive results regarding the short term effect of IMS in improving chronic myofacial pain and the pain related consequences. The mean pain, disability and quality of life scores also showed improvement at follow-up. Although this study suffered from attrition bias, the effect of IMS is still worth to be considered given the fact that nearly half of the patients included in this study had pain suffered from more than 3 years and the success rate of pain improvement was at least 30%. Considering the difficulty in treating chronic pain, we suggested conducting a high quality RCT to further evaluate the effect of IMS. Furthermore, as there seems a practitioner effect in determining the success of pain improvement, we decided to conduct an inter-rater reliability test to examine the consistency among practitioners in treating patients. Good consistency has to be achieved before the conduct of RCT.  42  Tables Table 5.1: Demographic Characteristics of Patients Not Included in the Analysis Patients who did not complete Patients who completed baseline baseline questionnaires questionnaires n=21 n=119 Mean Age 48.3 (sd=12.2) 46.6 (sd=12.9) Gender (F) 14 (67%) 70 (59%) Pain Duration less than 1 year 5 (24%) 20 (17%) 1 to 3 years 5 (24%) 42 (35%) 4 to 6 years 4 (19%) 19 (16%) 7 to 10 years 3 (14%) 11 (9%) more than 10 years 4 (19%) 27 (23%) Region of Pain Head 1 (5%) 18 (15%) Neck and shoulder 13 (62%) 43 (36%) Upper limbs 3 (14%) 25 (21%) Upper back 6 (28%) 36 (30%) Lower back 9 (43%) 72 (61%) Lower limbs 7 (33%) 49 (41%)  43  Table 5.2: Demographic Characteristics All included patients n=119 (100%) Mean Age 46.6 (sd=12.9) Gender (F) 70 (59%) Pain Duration less than 1 year 20 (17%) 1 to 3 years 42 (35%) 4 to 6 years 19 (16%) 7 to 10 years 11 (9%) more than 10 years 27 (23%) Region of Pain Head 18 (15%) Neck and shoulder 43 (36%) Upper limbs 25 (21%) Upper back 36 (30%) Lower back 72 (61%) Lower limbs 49 (41%) Mean Score Mean worst pain at 6.93 (sd=2.02) baseline Mean average pain at 5.15 (sd=1.93) baseline Mean ODI at 30.42 (sd=18.90) baseline (%)  Completed 1st follow-up n=64 (54%) 46.2 (sd=12.5) 38 (59%)  Completed 2nd follow-up n=15 (13%) 42.5 (sd=11.0) 9 (60%)  13 (20%) 25 (39%) 8 (12.5%) 8 (12.5%) 10 (16%)  2 (13%) 7 (47%) 2 (13%) 3 (20%) 1 (7%)  8 (12.5%) 26 (40%) 12 (18%) 18 (28%) 30 (47%) 28 (44%)  3 (20%) 7 (47%) 3 (20%) 7 (47%) 11 (73%) 8 (53%)  6.92 (sd=2.23)  6.73 (sd=2.12)  5.08 (sd=2.06)  4.80 (sd=2.08)  31.22 (sd=19.31)  28.11 (sd=14.24)  44  Table 5.3: Distribution of Pain Intensity Change at Follow-up Using Available Data First Follow-up (n=64, 54%) Deterioration No change Improvement Worst Pain 13 (20%, 10-30%) 11 (17%, 8-26%) 40 (63%, 51-75%) Average Pain 18 (28%, 17-39%) 11 (17%, 8-26%) 35 (55%, 43-67%) Second Follow-up (n=15, 13%) Deterioration No change Improvement Worst Pain 3 (20%) 2 (13%) 10 (67%) Average Pain 1 (7%) 3 (20%) 11 (73%) Number and percentage with 95% confidence interval (CI); CI is not presented in results of second follow-up because of the small sample size. Deterioration = pain score increased by 1 unit or more No change = pain score were the same at baseline and follow-up Improvement = pain score decreased by 1 unit or more  Table 5.4: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Available Data First Follow-up (n=64, 54%) Mean Difference (sd) 95% Confidence p-value Intervals 1. Worst pain -1.09 (2.34) -1.69, -0.50 0.0005 2. Least pain -0.63 (2.52) -1.25, 0.0036 0.0513 3. Average pain -0.86 (2.18) -1.40, -0.32 0.0025 4. Pain right now -0.47 (2.86) -1.18, 0.25 0.1948 Second Follow-up (n=15, 13%) Mean Difference (sd) 95% Confidence p-value Intervals 1. Worst pain -2.33 (2.74) -3.85, -0.81 0.0053 2. Least pain -1.47 (2.10) -2.63, -0.30 0.0171 3. Average pain -1.93 (2.49) -3.31, -0.55 0.0095 4. Pain right now -1.67 (2.58) -3.10, -0.24 0.026  45  Table 5.5: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Best Case Imputation First Follow-up (n=119) Mean Difference (sd) 95% Confidence p-value Intervals 1. Worst pain -1.58 (2.09) -1.96, -1.21 <.0001 2. Least pain -1.29 (2.43) -1.70, -0.82 <.0001 3. Average pain -1.61 (1.98) -1.97, -1.25 <.0001 4. Pain right now -1.69 (2.80) -2.20, -1.19 <.0001  Table 5.6: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using Worst Case Imputation First Follow-up (n=119) Mean Difference (sd) 95% Confidence p-value Intervals 1. Worst pain 0.38 (2.52) -0.082, 0.83 0.1067 2. Least pain 0.62 (2.41) 0.18, 1.06 0.0061 3. Average pain 0.27 (2.11) -0.11, 0.66 0.1584 4. Pain right now 0.62 (2.47) 0.17, 1.07 0.0073  Table 5.7: Mean Difference of Pain Intensity Scale from Brief Pain Inventory (BPI) Using LOCF First Follow-up (n=119) Mean Difference (sd) 95% Confidence p-value Intervals 1. Worst pain -0.59 (1.83) -0.92, -0.26 0.0006 2. Least pain -0.34 (1.87) -0.68, 0.0025 0.052 3. Average pain -0.47 (1.66) -0.77, -0.16 0.0028 4. Pain right now -0.25 (2.10) -0.63, 0.13 0.19  46  Table 5.8: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Available Data First Follow-up (n=64, 54%) Mean 95% Confidence p-value Difference (sd) Intervals 5a. Interfered general activity -1.80 (2.87) -2.52, -1.08 <.0001 5b. Interfered mood -1.42 (3.36) -2.26, -0.58 0.0012 5c. Interfered walking -1.22 (3.24) -2.04, -0.41 0.004 5d. Interfered normal work -1.89 (3.44) -2.75, -1.03 <.0001 5e. Interfered relations with others -1.38 (3.19) -2.17, -0.58 0.001 5f. Interfered sleep -1.55 (3.57) -2.44, -0.66 0.0009 5g. Interfered enjoyment of life -1.98 (3.28) -2.80, -1.17 <.0001 Second Follow-up (n=15, 13%) Mean 95% Confidence p-value Difference (sd) Intervals 5a. Interfered general activity -3.47 (2.33) -4.76, -2.18 <.0001 5b. Interfered mood -2.60 (2.50) -3.99, -1.22 0.0013 5c. Interfered walking -3.27 (3.79) -5.37, -1.17 0.0049 5d. Interfered normal work -3.40 (3.18) -5.16, -1.64 0.001 5e. Interfered relations with others -1.60 (2.75) -3.12, -0.079 0.041 5f. Interfered sleep -2.07 (3.61) -4.07, -0.065 0.044 5g. Interfered enjoyment of life -2.40 (2.41) -3.74, -1.06 0.0018  47  Table 5.9: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Best Case Imputation First Follow-up (n=119) Mean 95% Confidence p-value Difference (sd) Intervals 5a. Interfered general activity -2.41 (2.52) -2.87, -1.96 <.0001 5b. Interfered mood -2.30 (3.09) -2.86, -1.74 <.0001 5c. Interfered walking -2.24 (3.04) -2.79, -1.68 <.0001 5d. Interfered normal work -2.78 (3.07) -3.34, -2.22 <.0001 5e. Interfered relations with others -2.04 (2.86) -2.56, -1.52 <.0001 5f. Interfered sleep -2.68 (3.38) -3.29, -2.06 <.0001 5g. Interfered enjoyment of life -2.38 (3.10) -2.94, -1.82 <.0001  Table 5.10: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using Worst Case Imputation First Follow-up (n=119) Mean 95% Confidence p-value Difference (sd) Intervals 5a. Interfered general activity 0.35 (3.30) -0.25, 0.95 0.2496 5b. Interfered mood 0.53 (3.57) -0.11, 1.18 0.1055 5c. Interfered walking 0.39 (3.09) -0.17, 0.96 0.1717 5d. Interfered normal work -0.04 (3.44) -0.67, 0.58 0.8907 5e. Interfered relations with others 0.22 (3.07) -0.34, 0.78 0.4376 5f. Interfered sleep 0.75 (4.14) -0.002, 1.50 0.0507 5g. Interfered enjoyment of life 1.19 (4.51) 0.38, 2.00 0.0049  Table 5.11: Mean Difference of Quality of Life Items from Brief Pain Inventory (BPI) Using LOCF First Follow-up (n=119) Mean 95% Confidence p-value Difference (sd) Intervals 5a. Interfered general activity -0.97 (2.28) -1.38, -0.55 <.0001 5b. Interfered mood -0.77 (2.55) -1.23, -0.30 0.0014 5c. Interfered walking -0.64 (2.44) -1.09, -0.20 0.0049 5d. Interfered normal work -1.02 (2.68) -1.50, -0.53 <.0001 5e. Interfered relations with others -0.74 (2.43) -1.18, -0.30 0.0012 5f. Interfered sleep -0.83 (2.72) -1.33, -0.34 0.0011 5g. Interfered enjoyment of life -1.08 (2.59) -1.54, -0.60 <.0001  48  Table 5.12: Mean Difference of Oswestry Low Back Pain Disability Index Available Data First Follow-up (n=53, 45%) Mean Difference (sd) 95% Confidence Intervals ODI (%) -4.15 (21.48) -10.07, 1.77 Second Follow-up (n=14, 12%) Mean Difference (sd) 95% Confidence Intervals ODI (%) -8.25 (8.56) -13.2, -3.31  (ODI) Using p-value 0.17 p-value 0.0032  Table 5.13: Mean Difference of Oswestry Low Back Pain Disability Index (ODI) Using Sensitivity Analyses Best case imputation at first follow-up (n=107) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) -8.72 (18.59) -12.27, -5.18 <.0001 Worst case imputation at first follow-up (n=107) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) 5.66 (22.21) 1.43, 9.90 0.0093 LOCF at first follow-up (n=107) Mean Difference (sd) 95% Confidence Intervals p-value ODI (%) -2.69 (15.66) -5.69, 0.32 0.071  49  Table 5.14: Results from Pain Treatment Satisfaction Scale (PTSS) First follow-up with available data (n=56, 47%) Strongly Somewhat Neither agree agree agree nor n (%) n (%) disagree n (%) 1. happy with duration of 12 (34%) 22 (40%) 11 (20%) pain relief 2. pain relief quickly enough 11 (20%) 20 (36%) 19 (34%) 3. better physical health 23 (41%) 23 (41%) 7 (13%) 4. better outlook 23 (41%) 17 (30%) 12 (21%) 5. perform daily activities 17 (30%) 20 (36%) 15 (27%) more easily 6. more often leisure 16 (29%) 19 (34%) 19 (34%) activities 7. do things more 15 (27%) 19 (34%) 19 (34%) independently 8. better relationship with 15 (27%) 15 (27%) 22 (39%) others 9. improve mood 20 (36%) 19 (34%) 14 (25%) 10. concentrate better 16 (29%) 14 (25%) 20 (36%) 11. move around more easily 21 (38%) 18 (32%) 14 (25%) Very Satisfied Neither satisfied satisfied nor dissatisfied 12. overall satisfaction with 20 (36%) 28 (50%) 6 (11%) IMS Greatly Somewhat Meet exceeds exceeds expectation expectation expectation 13. level of pain relief 9 (16%) 18 (32%) 16 (29%) Definitely Probably Don’t know 14. IMS could be more effective  5 (9%)  21 (38%)  24 (43%)  Somewhat disagree n (%)  Strongly disagree n (%)  3 (5%)  1 (2%)  5 (9%) 1 (2%) 2 (4%) 3 (5%)  1 (2%) 2 (4%) 2 (4%) 1 (2%)  1 (2%)  1 (2%)  2 (4%)  1 (2%)  3 (5%)  1 (2%)  3 (5%) 5 (9%) 3 (5%) Dissatisfied  0 (0%) 1 (2%) 0 (0%) Very dissatisfied  2 (4%)  0 (0%)  Not quite meet expectation 11 (20%) Probably not 6 (11%)  Not meet expectation at all 2 (4%) Definitely Not 0 (0%)  50  Table 5.14: Results from Pain Treatment Satisfaction Scale (PTSS) (Continued) Second follow-up with available data (n=15, 13%) Strongly Somewhat Neither Somewhat agree agree agree nor disagree n (%) n (%) disagree n (%) n (%) 1. happy with duration of 7 (47%) 7 (47%) 0 (0%) 1 (7%) pain relief 2. pain relief quickly enough 4 (27%) 9 (60%) 1 (7%) 1 (7%) 3. better physical health 9 (60%) 5 (33%) 1 (7%) 0 (0%) 4. better outlook 6 (40%) 9 (60%) 0 (0%) 0 (0%) 5. perform daily activities 9 (60%) 4 (27%) 1 (7%) 1 (7%) more easily 6. more often leisure 8 (53%) 3 (20%) 3 (20%) 1 (7%) activities 7. do things more 9 (60%) 3 (20%) 2 (13%) 1 (7%) independently 8. better relationship with 6 (40%) 5 (33%) 3 (20%) 1 (7%) others 9. improve mood 7 (47%) 7 (47%) 1 (7%) 0 (0%) 10. concentrate better 5 (33%) 6 (40%) 2 (13%) 2 (13%) 11. move around more easily 8 (53%) 5 (33%) 1 (7%) 1 (7%) Dissatisfied Very Satisfied Neither satisfied satisfied nor dissatisfied 12. overall satisfaction with 10 (67%) 3 (20%) 2 (13%) 0 (0%) IMS Greatly Somewhat Meet Not quite exceeds exceeds expectation meet expectation expectation expectation 13. level of pain relief 7 (47%) 3 (20%) 3 (20%) 2 (13%) Definitely Probably Don’t know Probably not 14. IMS could be more 3 (20%) 6 (40%) 4 (27%) 0 (0%) effective  Strongly disagree n (%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) Very dissatisfied 0 (0%) Not meet expectation at all 0 (0%) Definitely Not 2 (13%)  51  Table 5.15: Results from Multiple Logistic Regression with Response = Worst Pain Improvement multiple logistic regression with response = worst pain improvement Reference Odds ratio 95% confidence interval Age <31 Age >60 14.12 0.54, 371.53 Age 31-40 Age >60 1.13 0.098, 13.18 Age 41-50 Age >60 0.69 0.068, 6.99 Age 51-60 Age >60 3.23 0.35, 30.21 Practitioner A Practitioner D 0.28 0.025, 3.14 Practitioner B Practitioner D 0.26 0.015, 4.38 Practitioner C Practitioner D 0.27 0.019, 3.76 Gender F Gender M 0.64 0.13, 3.08 Pain duration <1 yr Pain duration>10 yrs 0.32 0.032, 3.21 Pain duration 1-3 yrs Pain duration>10 yrs 1.04 0.14, 7.71 Pain duration 4-6 yrs Pain duration>10 yrs 3.13 0.16, 60.62 Pain duration 7-10 yrs Pain duration>10 yrs 1.15 0.10, 13.0 Initial worst pain 1-3 Initial worst pain 7-10 0.13 0.01, 1.63 Initial worst pain 4-6 Initial worst pain 7-10 0.41 0.06, 2.82  Table 5.16: Results from Multiple Logistic Regression with Response = Average Pain Improvement multiple logistic regression with response = average pain improvement Reference Odds ratio 95% confidence interval Age <31 Age >60 0.82 0.044, 15.26 Age 31-40 Age >60 0.34 0.02, 5.88 Age 41-50 Age >60 0.068 0.004, 1.05 Age 51-60 Age >60 0.21 0.014, 3.07 Practitioner A Practitioner D 0.021 <0.001, 0.049 Practitioner B Practitioner D 0.028 <0.001, 0.84 Practitioner C Practitioner D 0.12 0.006, 2.41 Gender F Gender M 1.0 0.19, 5.40 Pain duration <1 yr Pain duration>10 yrs 0.36 0.029, 4.51 Pain duration 1-3 yrs Pain duration>10 yrs 1.05 0.096, 11.54 Pain duration 4-6 yrs Pain duration>10 yrs 9.59 0.45, 206.30 Pain duration 7-10 yrs Pain duration>10 yrs 0.64 0.034, 11.97 Initial worst pain 1-3 Initial worst pain 7-10 0.007 <0.001, 0.153 Initial worst pain 4-6 Initial worst pain 7-10 0.043 0.004, 0.42  52  Figures Figure 5.1: Flow Chart for Population Identification Received IMS treatment (April 1st, 09 – Feb 1st, 10) n=155 Acute Pain (pain for less than 3 months) n=15 Chronic Pain (pain persists for 3 months or more) n=140 Refuse to Complete Questionnaires n=21 Completed Baseline Questionnaires n=119  Left Clinic n= 32 No 1st Follow-up Questionnaires n=55  Completed 1st Follow-up Questionnaires n=64  Refuse to complete n= 14 Censoring n= 9  Left Clinic n= 17 nd  No 2 Follow-up Questionnaires n=49 Completed 2nd Follow-up Questionnaires n=15  Refuse to complete n= 22 Censoring n= 10  53  CHAPTER 6: Study 3-Assessing the Inter-Rater Reliability of Intramuscular Stimulation Practitioners  6.1  Introduction  The second chart review (chapter 5) showed the possibility of a practitioner effect with regard to pain improvement: three practitioners had only ¼ probability of the fourth one to reach success (at least 1 unit reduction in worth pain score).  Differential effect is a  real possibility in all needling techniques as there is a learning curve. Moreover, we already described in chapter 2 the difficulty to make a precise and reliable diagnosis of myofascial pain which leads to treatment strategy, hence effects. Therefore, we felt that testing the consistency of making myofascial pain diagnosis and treating patients among IMS practitioners was an important information to collect before carrying out a RCT. We decided then to carry out an inter-rater reliability study to assess the consistency among five IMS practitioners in identifying the same signs of myofascial pain. The primary objective of the study was to test the agreement among IMS practitioners in identifying number of tender taut bands along the spine and in the body regions. Secondary objective was to test the consistency of IMS practitioners in recording the taut bands within precise muscles and the signs of autonomic dysfunction.  6.2  Methods  6.2.1  Study Design  The inter-rater reliability study was conducted during one day in one IMS clinic in Vancouver. Twenty patients who suffered from chronic myofascial pain were invited to participate in the test. Each patient was examined by five different IMS practitioners at the clinic. Practitioners carried out 15 minutes clinical examination on every patient and recorded clinical findings such as tender taut bands and signs of autonomic dysfunction on standard forms. Results were collected and analyzed by research team members who were independent to the clinic.  6.2.2  Study Sample  Recruitment was done at IMS clinic during office hours two weeks before the study 54  started. Practitioners invited their current patients who suffered from myofascial pain in lower back or lower extremities for at least 3 months to participate in the study. There was no age or sex restriction. A total of 20 patients were then recruited and each of them signed a consent form.  6.2.3  Practitioners  All five certified IMS practitioners practicing at the IMS clinic participated in this study. All practitioners had practiced IMS for over 5 years and three of them were current IMS instructors. All of them had received standard IMS training to become IMS certified, following Gunn’s book (2007) which describes standard clinical examination and treatment strategy as a reference. Before the inter-rater reliability study, a meeting of 2 hours with IMS practitioners and research team members was held to discuss the study protocol and review definitions of clinical signs and treatment strategy to ensure common interpretation by practitioners.  6.2.4  Study Procedures  This was a one day test with four different sessions of 5 subjects each. The five subjects were allocated to five different rooms where clinical examination took place. Therefore, the five IMS practitioners could examine the five subjects at the same time. Each examination took about 15 minutes. When practitioners finished one examination, they handed in the completed examination form to the research coordinator and automatically shifted to the next room to examine another patient.  The process continued, until every  practitioner had examined the five subjects. Another session took place right after five minutes break.  6.2.5  Clinical Examination  IMS deep needling technique targets specifically points of palpable muscle contraction (tender taut band) and the associated paraspinal muscles (semispinalis, rotators, multifidus and spinalis) along the spine. Therefore, identification of palpable tender taut bands and the associated tender spinous muscles are the keys for clinical examination and  55  the subsequent strategic treatment plan. In this study, tender taut band defined as a palpable rope-like hardening of muscles defined as a group of muscle fibers that may be passively stretched by the contracture of contraction knots in a trigger point in the center of the fibers (Simon 1992). In this reliability test, examination was confined to the lower part of the body. Practitioners focused palpation on spinous muscles along T6-T12 and L1-L5. Muscles on the back (Latissimus dorsi, quadratus lumborum, lliocostalis, longissimus), around hip and thigh (tensor fasciae latae, gluteus medius and maximus, pectineus, adductor longus and magnus, rectus femoris, quadratus medialis and lateralis, pes anserinus, semi tendinosis and membranosis, biceps femoris) and leg (gastrocnemius, soleus, tibialis anterior, extensor digitorum longus, peroneus) were examined. Autonomic dysfunction is very common in myofascial pain patients. Identifying autonomic symptoms can help finding contracted muscles which are difficult to be palpated. In this study, autonomic disorders such as differential sweating (sudomotor reflex), skin temperature (vasomotor reflex), goose bumps (pilomotor reflex), trophic changes (hair loss or cracking nails) and oedema were documented during clinical examination to test the consistency of findings. . 6.2.6  Outcome Measures  Primary outcome was the identification of number of tender taut band in body regions (back, hip and thigh, leg) and along the spine (thoracic and lumbar segments). Secondary outcomes were the identification of tender taut band at each muscle level and the identification of signs of autonomic dysfunction including oedema, pilomotor reflex (goose bumps), decrease in skin temperature (vasomotor reflex), abnormal sweating (sudomotor reflex) and trophic changes (cracking nails or hair loss). Outcomes assessment was collected on a standardized form that had the list of all muscles to examine and signs of autonomic dysfunction. A check box was next to each item on the form. Practitioners checked the corresponding boxes when they identified the presence of  56  tender taut band in the particular region, muscles and/or presence of autonomic dysfunction.  6.2.7  Ethics  The study proposal and related materials were approved by UBC Clinical Research Ethics Board on 8th June, 2009.  6.2.8  Statistical Analysis  Primary analysis focused on assessing the consistency among practitioners in identifying number of taut bands in spinous muscles, back muscles, hip and thigh muscles, and leg muscles using intra-class correlation coefficient (ICC). Intra-class correlation coefficient (ICC) is commonly used in measuring inter-rater reliability when continuous variables (i.e. counting the number of taut bands in this study) are applied where ICC=0 indicates no agreement and ICC=1 indicates perfect agreement (Shrout & Fleiss 1979). Interpretation of ICC is similar to kappa statistics which is shown below (Garson 2009). Secondary analysis was the agreement among practitioners in identifying each item on autonomic dysfunctions and identifying taut band in each muscle (presence/absence) using multiple raters Kappa. Multiple raters Kappa is widely used in measuring reliability for nominal variables and discounting for the proportion of agreement expected by chance alone if more than 2 raters are involved (Fleiss 1971). Kappa statistic in general can  be  interpreted  as  follow:  0=poor,  0.01–0.20=slight,  0.21–0.40=fair,  0.41–0.60=moderate, 0.61–0.80=substantial and 0.81–1=almost perfect agreement (Sim et al 2005). We also computed overall kappa values for each extremity region and for autonomic dysfunction by simple averaging. All statistics were calculated at alpha=0.05 and were performed with SAS version 9.1 Windows, SAS Institute Inc., NC, USA.  57  6.3 Results 6.3.1  Sample Characteristics  Twenty subjects were recruited in the study of which 12 (60%) were female. Mean age of these 20 participants was 48.8 (sd =11.2). Their regions of pain were: low back pain for 9 (45%), leg pain for 4 (20%) and 7 (35%) had both back and leg pain. All participants were diagnosed as chronic myofascial pain patients and their pain persisted at least 3 months by the time they received first IMS treatment. Most of them (55%) had suffered from pain for 1-3 years at the time of the test. 6 of them (30%) had pain for 4-6 years and 3 (15%) had pain for less than 1 year but more than 3 months.  6.3.2  Inter-rater Reliability of Identifying Tender Taut Bands  6.3.2.1  Identification of Number of Taut Bands in Different Body Regions  Consistency of identifying number of taut bands in different parts of the body was tabulated in Table 6.1. The ICC values for thoracic and lumber spinous muscles were 0.66 and 0.68 respectively. ICC value was 0.64 for the number of taut bands found in muscles at the back. For hip/thigh region, the consistency in identifying the number of taut bands was 0.77. Finally the ICC value was 0.69 for leg muscles. All the ICC values obtained indicated substantial agreement among practitioners in identifying number of taut bands in each region.  6.3.2.2  Identification of Taut Bands in Each Muscle  Agreement in identifying taut bands in each muscle in back region, hip and thigh region and leg region were tabulated in Table 6.2, Table 6.3 and Table 6.4 respectively. Table 6.2 shows reliability in back muscles. Kappa values in back muscles ranged from 0.13 to 0.39. The average kappa value was 0.25 (sd=0.09) showing fair agreement. Table 6.3 shows the multiple raters kappa values of tender taut bands in thigh or hip muscles. The kappa values ranged from -0.05 (poor agreement) to 0.46 (moderate agreement).  The  average was 0.18 (sd=0.1) showing overall slight agreement. For leg muscles, multiple raters kappa values were from 0.03 to 0.34 indicating slight or fair agreement (Table 6.4). The average kappa was 0.16 (sd=0.1).  58  6.3.2.3  Identification of Autonomic Dysfunction  Multiple-raters kappa results for autonomic dysfunction identification reliability are presented in Table 6.5. It shows that the reliability of identifying autonomic dysfunction was between -0.11 and 0.2 (mean=0.016, sd=0.13) which fell in the categories of poor agreement or slight agreement.  6.4 Discussion In identifying the number of tender taut bands in different regions, there was a good consistency among practitioners shown by ICC values which varied from 0.64 to 0.77 (Table 6.1). However, relatively low kappa values were obtained when measuring the consistency in identifying taut bands in specific muscles. Kappa values ranged from -0.05 (poor agreement) to 0.46 (moderate agreement) were obtained (Tables 6.2 to 6.4). These results indicated substantial agreement among practitioners in identifying number of taut bands to treat in different parts of body, but practitioners might treat different muscles in that particular region due to great discrepancy (low kappa) at muscle level. This maybe due to the fact that IMS practitioners have difficulty in identifying muscle anatomy correctly or the fact that IMS practitioners are examining patients in different ways. However, it raises the question of consistency in dispensing the IMS intervention between different IMS practitioners. This result may then explain the difference in effect between practitioners observed during the second chart review (chapter 5). For the reliability in examining autonomic dysfunction, the kappa statistics indicated that practitioners reached only poor or slight agreement with highest kappa value achieved for skin oedema (kappa=0.2). Poor agreement was found in identifying vasomotor, pilomotor, sudomotor dysfunction and trophic changes. Reason for the poor consistency may receive several explanations. Firstly, it was acknowledged that practitioners relied more on their own experience and usual practice to examine patients rather than following strictly the original standard of examination. Secondly, practitioners claimed that it was exhausting to examine 20 patients with too many variables (21 pairs of muscles, 12 spinal segments, 5 autonomic symptoms) to  59  record. They believed that time was too limited to carry out a thorough clinical examination. Finally, autonomic symptoms such as vasomotor and sudomotor reflex were considered to be too subjective to record. Although this study suggests inconsistency among IMS practitioners in identifying specific muscle taut band, the results were useful in giving an interesting insight for improving consistency among the team of 5 IMS practitioners. The results obtained in this study may then represent a baseline reference against which we can compare the team performance after proper training. From the experience in this study, we recommended IMS practitioners’ team to carry out comprehensive training and demonstration to ensure standardization of the examination and consistency in reporting signs. We also recommended practitioners to discuss and share their examination experience with each other to reach a higher degree of agreement. Good collaboration between practitioners will be the bridge to success. To avoid that practitioners’ fatigue interfere with the quality of examination, we suggested that examination should focus only on a limited number of key muscles, to be decided and agreed upon in advance – or alternatively to give more time to examine the patients.  If we keep the same format  (about 15 minutes per patient), we recommended to drop by two-third the number of examination variables. Less important muscles should be eliminated. Also, the examination form should be developed by all practitioners so that all the examination variables on the form are agreed by all practitioners and practitioners feel comfortable using the form. Finally, subjective outcomes such as vasomotor and sudomotor reflex should be eliminated.  6.5 Conclusion From this study, good agreement between IMS practitioners was found at regional level regarding the number of taut bands identified. However, low consistency was found in examining taut bands in each muscle and identifying autonomic dysfunctions. This result raises the question of possible IMS treatment discrepancy between practitioners. Substantial agreement among practitioners in examining patients has to be achieved before carrying out a RCT.  60  Tables Table 6.1: Intra-class Correlation Coefficient (ICC) for Identifying the Number of Taut Bands in Different Regions Regions Intra-class Correlation Coefficient (ICC) Spinous muscles from T6 to T12 0.66 Spinous muscles from L1 to L5 0.68 Muscles at the back 0.64 Muscles at hip and thigh area 0.77 Muscles at leg area 0.69  Table 6.2: Multiple Raters Kappa of Identifying Taut Band in Each Back Muscle L/R Muscles Kappa 95% CI (lower) 95% CI (upper) L Latissimus dorsi 0.14 0.00 0.28 R Latissimus dorsi 0.22 0.08 0.36 L quadratus lumborum 0.26 0.13 0.40 R quadratus lumborum 0.34 0.20 0.48 L lliocostalis 0.20 0.06 0.34 R lliocostalis 0.30 0.16 0.44 L longissimus 0.13 -0.01 0.27 R longissimus 0.39 0.25 0.53 Average 0.25 SD=0.09  61  Table 6.3: Multiple Raters Kappa of Identifying Taut Band in Each Hip/Thigh Muscle Kappa 95% CI (lower) 95% CI (upper) L tensor fasciae latae 0.32 0.18 0.46 R tensor fasciae latae 0.16 0.02 0.30 L gluteus medius 0.17 0.03 0.31 R gluteus medius 0.07 -0.07 0.21 L gluteus maximus 0.28 0.14 0.42 R gluteus maximus 0.16 0.02 0.30 L pectineus 0.14 0.00 0.28 R pectineus 0.09 -0.05 0.23 L adductor longus and magnus 0.13 -0.01 0.26 R adductor longus and magnus 0.15 0.02 0.29 L rectus femoris 0.19 0.06 0.33 R rectus femoris 0.46 0.32 0.60 L quadratus medialis -0.05 -0.19 0.08 R quadratus medialis 0.12 -0.02 0.26 L quadratus lateralis 0.15 0.02 0.29 R quadratus lateralis 0.25 0.11 0.38 L pes anserinus 0.14 0.00 0.28 R pes anserinus 0.22 0.08 0.36 L semi tendinosis & membranosis 0.26 0.12 0.40 R semi tendinosis & membranosis 0.21 0.08 0.35 L biceps femoris 0.16 0.02 0.30 R biceps femoris 0.12 -0.02 0.26 Average 0.18 SD=0.10  62  Table 6.4: Multiple Raters Kappa of Identifying Taut Band in Leg Muscle Kappa 95% CI (lower) L gastrocnemius lateral head 0.14 0.00 R gastrocnemius lateral head 0.04 -0.10 L gastrocnemius medial head 0.34 0.20 R gastrocnemius medial head 0.09 -0.05 L soleus 0.16 0.02 R soleus 0.04 -0.10 L tibialis anterior 0.16 0.02 R tibialis anterior 0.14 0.00 L extensor digitorum longus 0.21 0.07 R extensor digitorum longus 0.03 -0.10 L peroneus 0.24 0.10 R peroneus 0.30 0.16 Average 0.16 SD=0.10  Table 6.5: Multiple Raters Kappa of Identifying Autonomic Dysfunction Kappa 95% CI (lower) Vasomotor (decrease in skin 0.03 -0.11 temperature) Pilomotor (goosebumps) -0.12 -0.25 Sudomotor (abnormal sweating) -0.11 -0.25 Trophic changes (cracking nails/ 0.03 -0.07 hair loss) Oedema 0.20 0.07 Average 0.016 SD= 0.13  95% CI (upper) 0.28 0.18 0.48 0.23 0.30 0.18 0.30 0.28 0.35 0.17 0.38 0.44  95% CI (upper) 0.16 0.02 0.03 0.13 0.34  63  CHAPTER 7: Summary of Findings, Conclusion and Future Work  7.1  Introduction  Chronic myofascial pain is a public health problem without efficacious treatment. Common drugs such as antidepressants and opioids are of limited long term efficacy and often associated with numerous adverse events. Complementary and alternative medicine (CAM) is therefore popular for people who suffer from chronic pain. One common CAM is dry needling which includes traditional Chinese acupuncture and dry needling of trigger point (TrP). Intramuscular stimulation (IMS) is a popular form of TrP needling and is utilized in multidisciplinary pain centers. Many chronic pain patients seem to appreciate the effects of IMS in alleviating their pain as seen by letters and testimonials. However, there is no solid clinical evidence supporting IMS effect. We feel that it is important to further evaluate the effect of IMS by a high quality randomized controlled trial (RCT). This thesis included three studies which were conducted to help design and exploring the feasibility of conducting an IMS RCT in terms of recruitment, population characteristics and sample size estimation. The main findings of the three studies are summarized as follow.  7.2  Summary of Findings  Study 1: First Retrospective Chart Review This study describes well the population treated at the IMS clinic. Of the 100 studied patients, 30% had pain for 10 or more years and most of the patients (more than 80%) had more than one region of pain. Lower back pain was the leading pain complaint, followed by neck and shoulder pain. The median for the number of treatments received was six. Of the 100 charts, 78 had records of pain control by practitioners. Of which 74 were qualified as improvements. Assuming the missing information in 22 charts corresponded to pain worsening, the success rate of IMS in improving pain would be 74% which met our study hypothesis (at least 50%). However, these results were prone to a positive bias because of practitioners’ subjective report regarding pain improvement. We then tried to contact patients by phone with the objective to collect patients’ comments regarding treatment effect. Because of the low response rate (12%) in this  64  telephone interview, the results cannot be interpreted. These results lead the clinic to modify the patient chart recordings by incorporating standard questionnaires for patients to fill out. So we decided to carry out a second chart review 10 months after implementing the new patient chart with standard recordings from patients’ feedback.  Study 2: Second Retrospective Chart Review The population characteristics obtained from this chart review were similar to the first chart review. Of the 119 patients who met the eligibility criteria and who had completed the questionnaires, 64 (54%) completed the first follow-up (fourth treatment) and 15 (13%) completed the second follow-up (eighth treatment). Assuming all the missing data was of pain deteriorated cases, we found that the success rate of worst and average pain improvement (at least 1 unit reduction in pain score) were 34% (95% CI: 25%, 43%) and 30% (95% CI: 22%, 38%) respectively. Among 64 patients who had completed the first follow-up (using available data), the success rates were 63% (95% CI: 51%, 75%) and 55% (95% CI: 43%, 67%) respectively. The success rates that we found in this study were a bit lower than our hypothesized value (at least 50%) if the most conservative estimation is taken into account. Based on available data, the mean improvement of worst and average pain were -1.09 (95% CI: -1.69, -0.50) and -0.86 (95% CI: -1.40, -0.32) respectively at first follow-up. And they were -2.33 (95% CI: -3.85, -0.81) and -1.93 (95% CI: -3.31, -0.55) respectively at second follow-up. Compared to several high quality acupuncture RCT treating chronic low back pain, our results were slightly less important than the acupuncture effect measured in these studies. This maybe due to the fact that there were more treatments (12 or more sessions) in the acupuncture studies compared to our study (8 sessions). Also, patients involved in clinical trials tend to show higher improvements in response due to the fact that they are being studied. Besides, positive bias may occur when we have practitioners who are likely to bias in favour of needling technique to carry out their own trials. Other results regarding disability and quality of life items on Brief Pain Inventory (BPI)  65  also showed improvement. And we found that most of the patients who completed the first follow-up questionnaires (about 90%) were satisfied with IMS treatment. Regarding logistic regression model to predict worst and average pain improvement, we did not find any predictors associated with pain improvement, except initial pain score. However, this may be due to a regression to mean phenomenon. Another interesting finding was that practitioners may lead to different treatment outcomes. This raised the issue of possible lack of consistency among IMS practitioners in treating patients. Therefore, we decided to conduct an inter-rater reliability test before the set up of RCT.  Study 3: Inter-rater Reliability Test This study consisted of 20 patients and 5 practitioners (raters). Examination focused on lower back and lower limbs. Regarding the consistency in identifying number of taut bands in paraspinal muscles along the spine, the intra-class correlation coefficient (ICC) was 0.66 and 0.68 in thoracic segments and lumbar segments respectively. Regarding the consistency in identifying number of taut bands in back, hip, thigh and leg regions, the ICC varied from 0.64 to 0.77. Regarding the consistency in identifying taut bands in each muscle, multiple raters kappa values ranged from -0.05 (poor agreement) to 0.46 (moderate agreement). Lastly, the consistency of identifying autonomic dysfunction was also low, with multiple raters kappa ranged from -0.16 to 0.20 (poor agreement). The reliability of identifying number of taut bands met our study hypothesis (ICC of 0.6), but the reliability of identifying taut bands in each muscles did not meet our hypothesized value (kappa of 0.6). The great discrepancy among practitioners in identifying taut bands in each muscle and autonomic symptoms raise concerns that practitioners may treat patients differently. However, substantial consistency was obtained in identifying number of taut bands along the spine and in different body regions. Therefore it may also possible that different practitioners identified the same problem but had difficulties to relate the myofascial pain symptoms to precise muscles. Other reasons leading to the poor consistency obtained in this study include the practitioners’ self confidence to rely on their own clinical experience rather than standard training practice; practitioners’ fatigue in examining 20 patients in a few hours; and the large number of variables to record during a short period of time.  66  7.3  Conclusion from the Three Studies  The two chart reviews showed positive results regarding IMS in relieving chronic pain and improving pain consequences. Although loss to follow-up was important (reflecting usual practice), we believe that the success rate of pain improvement in the most conservative approach is high enough to be considered given the difficulty in treating chronic pain. Therefore, we suggest conducting a high quality RCT to further evaluate the effect of IMS. The information obtained from the two chart reviews regarding population characteristics and success rate of pain improvement will be used in justifying the type and size of sample in the design of RCT. Good consistency among practitioners in treating patients has to be achieved before the conduct of RCT. Therefore, we suggest conducting another inter-rater reliability test. Before the start of another reliability test, discussions among practitioners and comprehensive trainings for practitioners have to be launched to ensure the standardization of clinical examination. Also, a new examination form with fewer variables needs to be developed to avoid practitioners’ fatigue affecting the consistency of the results.  7.4  Future Work: Conduct of RCT  According to what we have found in the review of literature (Chapter 2), most of the published acupuncture trials involve the evaluation of traditional Chinese acupuncture rather than that of dry needling of trigger points (TrP). We also found only two trials assessing the difference in the effect of alleviating chronic pain between traditional acupuncture and TrP needling, but the results were controversial. The existing evidence shows that acupuncture is better than sham therapy in reducing chronic low back pain only in the short-term, there is not enough evidence showing acupuncture is superior to sham regarding intermediate and long-term benefits (Furlan et al 2005, Johnston et al 2008). The effect of TrP needling seems in the same range as the effect of TrP injections (Cummings et al 2001). Evidence of TrP needling in alleviating chronic myofascial pain when compared to sham is still limited. Regarding the efficacy of IMS, two RCTs showed positive results, but limitation due to low methodological quality, small sample size and no sham needling comparison (Ga et al 2007, Gunn 1980). Overall, it seems that classic acupuncture and other needle therapies developed specifically to control  67  myofascial pain may work to decrease chronic pain. However, there are only a few trials of high methodological quality. Most of them are limited by: 1) small sample size; 2) lack of concealment of allocation; 3) lack of long term follow-up; 4) no description of co-intervention  during  follow-up  periods;  5)inexperienced  practitioners;  6)no  independent investigator; 7) no true sham therapy; and 8) lack of blinding or evaluation of successful blinding. Considering the need of more high quality trials with long term follow-up for both classic acupuncture and TrP needling (including Ah-Shi acupuncture and IMS); and the lack of evidence showing the differences in the needling effect against sham and among different needling techniques, we propose to conduct a three-arm RCT with IMS, traditional Chinese acupuncture and sham needling. Our study will be conducted by an independent team of investigator with the participation of experienced acupuncturists and IMS practitioners to reduce possible biases. We will assess the success of blinding patients at the end of intervention. Furthermore, our study will provide long-term follow-up of patients (1 year after the end of intervention). Long-term follow-up has always been an issue in pain trials because patients withdraw participation and change their pain medication over time; making trial results difficult or impossible to interpret. For instance, the use of another analgesic or co-intervention that is superior to the study intervention may have an effect on pain control. It is not possible to ask patients to keep the usual treatment unchanged over time. Moreover, for ethical reasons, once proven efficacious in the short term, all patients should have access to the study intervention. Therefore the use of a classic outcome like “change of pain score over time” is not good for assessing the long term effect of a pain intervention. This issue is not specific to the assessment of needling therapies. None of the drug trials identified for treating chronic pain provide answers regarding long term effect. A good outcome therefore should include both pain intensity change and the use of medication. We then suggest the use of a “success/failure” outcome where “success” defined as (i) pain score is decreased by 1 unit compared to baseline assessment and (ii) the amount and types of analgesic drugs is the same or reduced and (iii) no other pain management device or strategy has been used. Otherwise, the intervention will be considered as “Failure”. Furthermore, loss to follow-up is a  68  source of major problem that may lead to absence of long term assessment. Therefore, it is suggested that investigators could often offer financial compensation to participants for their time lost from participation (Grimes et al 2002). Apart from monetary reward, incentives such as coupons, gifts or a price draw after each completion of follow-up assessment are also recommended to keep patients’ participation throughout the study. Methods of follow-up assessment should be convenient and easy to access. Web-survey seems to be a good tool because patients can complete follow-up assessment whenever they feel comfortable. In our proposed trial, follow-up assessment is conducted by telephone which is easy and straight forward; we may also implement a web-survey as another form of follow-up assessment. A diary can be provided to patients at the end of the intervention to collect information regarding degree of pain, functional limitations, use of pain medications and alternative treatments. We also recommend the use of BC administrative databases with the profiles regarding drugs and other health services before and after interventions. We thought that the use of administrative databases after obtaining subjects’ comments could provide a good result of the long-term effect of interventions. All these features are part of the RCT proposal which is presented in Chapter 8 of this thesis. The proposal has been submitted to Canadian Institute of Health Research (CIHR) in March 2010.  69  CHAPTER 8: A Proposal for a Randomized Controlled Trial (RCT)  8.1 Title of the Study Proposal Needle Therapy to Treat Chronic Myofascial Pain: Intramuscular Stimulation and Traditional Chinese Acupuncture Against Sham Needle  8.2 Background Chronic musculoskeletal pain is an important health problem, as it is difficult to treat, and has huge consequences for the patients (source of disability, poor quality of life and financial and emotional consequences) and society (substantial direct, e.g. healthcare and indirect cost e.g. lost productivity) after the initial acute pain episode, an important component that can lead to pain chronicity is the development of a myofascial pain syndrome (MPS).  Whatever the mechanisms of MPS development, once in place it has  a tendency to self maintain and most often it resists conventional treatments.  In this  situation, patients try alternative treatments, especially needle therapy. A meta-analysis showed that classic acupuncture (using meridian points) has some effects on reducing pain in the short term.  Other needle therapies such as intra-muscular stimulation (IMS),  based on a different pathophysiological model than acupuncture, also seem to be beneficial for patients with chronic pain.  However research in this domain, although  interesting, suffers from poor quality, thus results are not reliable.  Our project is aimed  at comparing the respective effects of acupuncture and IMS to sham needle treatment for controlling chronic pain.  To keep focused, we decided to concentrate on chronic low  back pain (CLBP), because it is the most important debilitating chronic pain problem and a well recognized societal burden worldwide. The review will first describe briefly the problem of CLBP and will then explain the mechanism of chronic pain, through the development of chronic myofascial pain.  After a short review of conventional  treatments, this section will then describe the different types of needle therapies and will present relevant study results.  This whole section will serve as a rationale for our  project.  Low back pain (LBP), defined as pain located in the lumbar vertebrae area (Stephen 70  2006), is a major public health and economic problem worldwide (Bernard 2005), especially when it is chronic. In 2003, the World Health Organization reported lifetime prevalence of LBP ranging from 50 to 80% (Hammill et al 2008, Woolf et al 2003). In developed countries point prevalence varies from 12 to 37% (Gourmelen et al 2007, Maniadakis et al 2000, Schmidt et al 2007, Walker 2000), with a peak prevalence between age 45 and 65 (Church et al 2007, Devon 2007, Hammill et al 2008). Among people with an acute episode of LBP, 60 to 70% recover within 6 weeks and 80 to 90% within 12 weeks (Andersson 1999). For those individuals (10-20%) who do not recover within 3 months the problem becomes “chronic” (Andersson 1999, Dworkin 2002, Leclerc et al 2006).  Chronic low back pain (CLBP) is the most frequent condition leading to disability, work loss, psycho-social problems, and impaired quality of life (Andersson 1998, Al Obaidi et al 2003, Devon 2007, Hammill et al 2008, Keeley et al 2008, Marin et al 2006). Patients experience difficulty with daily functions (lifting, dressing, washing). Other problems include the inability to stand or sit comfortably and slowed walking compared to people without back pain (Al Obaidi et al 2003, De Souza et al 2007). A survey in the UK (Dodd 1997) revealed that pain compelled 8% of back pain patients to spend at least one day lying down in the preceding 4 weeks, and 30% to restrict their daily activities during the same period . CLBP also greatly affects the quality of sleep; Martin et al showed that over 90% of patients with CLBP had restless sleep and insomnia, a source of depression, anxiety and stress (Keeley et al 2008, Marin et al 2006). As a consequence, their social life is greatly affected with reduced leisure activities and social interactions, creating social isolation (Keeley et al 2008). Of concern is that over 75% of patients with CLBP suffer from at least one clinical or subclinical psychiatric disorder (depressive or anxiety symptomotology) (Polatin et al 1993). Apart from affecting individuals’ health and quality of life, CLBP is the most frequent cause of absence from work and workers’ compensations, creating an enormous economic burden on society (Andersson 1998, Devon 2007, Maniadakis et al 2000). It is estimated that LBP contributes to 40 to 68% of all lost work days (Andersson 1999, Manchikanti 2000, van Tulder et al 2002). In the United Sates LBP causes approximately 175 million work days lost per year, with an  71  estimation of USD$28 billion productivity loss annually (Rizzo et al 1998) and an overall economic burden of over USD$40 billion in direct medical treatment, costs associated with disability, and absenteeism from work (Andersson 1999, Hammill et al 2008). Among LBP-related costs, the “chronic” pain patients are responsible for over 90% of the total costs and utilize the majority of allocated resources (Furlan et al 2002). Similar economic figures are found in the UK: £1.6 billion for direct medical cost, £10.7 billion for informal care and disability and £9.1 billion related to work absenteeism (Maniadakis et al).  Acute LBP commonly occurs in people who have predisposing factors such as obesity, sedentary work, frequent heavy lifting, repetitive improper movement, or exposure to vibrations (Andersson 1999, Church et al 2007, Devon 2007, Hoogendoorn et al 2000, Stephen 2006, Wilder et al 1988).  Specific conditions have been identified such as  direct trauma of the spine or the back, spinal disc degeneration, disc herniation, spondylosis, osteoporosis, tumor infusion, virus infection, inflammation, and rheumatic diseases (Church et al 2007, Hammill et al 2008, Ross 2006, van Tulder et al 2002). However, in most cases (80-90%), due to weak associations among symptoms, examination findings, and anatomic changes, a precise pathoanatomic cause cannot be reliably confirmed by physical examination or diagnostic testing (Hammill et al 2008, Wand et al 2008). A study of acute LBP by Deyo et a1 (1992, 2001)  showed that 10%  was caused by degenerative disks, 4% by disc herniation, 4 % by compression fractures, 3% and 2% by spinal stenosis and spondylolisthesis, respectively, and about 2% in relation to visceral diseases. The remaining cases were “idiopathic LBP”, due to “non-specific” causes which could not be ascribed to a precise pathoanatomical cause (Deyo et al 2001, van Tulder et al 2002, Wand et al 2008).  Many of the causes listed such as degenerative or herniated disc, spondylosis are responsible for the development of radiculopathy due to nerve root impingement (Benoist 2002, Gorpille et al 1998, Rhee et al 2006). Disk disruption is considered the most common cause of radiculopathy-induced LBP, with 98% involving L4-5 or L5-S1 interspaces (Frymoyer 1988).  It occurs with sudden physical effort when the trunk is 72  flexed or rotated (Borenstein 1996). Radiculopathy leads to nerve damage or dysfunction which may account for the development of myofascial pain syndrome (see below). The cause of chronic LBP following an acute episode of back pain is complex and not completely understood.  Some authors have proposed that the development of a chronic  myofascial pain syndrome in the follow up phase of an acute back pain episode may account for a significant portion of ‘non-specific’ CLBP. It has been proposed that myofascial pain syndrome (MPS) develops through two main mechanisms (primarily muscular or secondarily to peripheral neuropathy) that may both be acting in the context of acute back pain injury (see below).  Independent of the pathways that operated  initially, once myofascial pain syndrome is in place it may persist and develop through a self sustained process that it totally independent from the initial cause that lead to its development; this cause may have actually disappeared at the time of chronic pain. Next we will describe MPS signs and symptoms and explain the mechanism of development that has been well documented.  Myofascial pain syndrome is characterized by muscles in a contracted state with increased tone and stiffness, and that contain myofascial trigger points (Simons et al 1999). Myofascial trigger point (TrP) is defined as self-sustaining hyperirritable spot located in taut band of skeletal muscle with zone of tenderness (Simons 1995, 1999). Direct compression or palpation of TrP provokes a sharp contraction of muscle fibers that induces radiating and aching type of pain into localized and referred area (Wheeler 2004), with a strong patients’ reaction identified as “jump sign” (Gerwin 2001, Wheeler 2001). Other TrP characteristics include muscle weakness, decreased work tolerance, limitation of movement’s amplitude, impaired muscle coordination, stiff joints and fatigue (Friction et al 1985). Signs of sympathetic activity are also frequent in the zone of TrP: abnormal sweating (sudomotor reflex), decrease in skin temperature (vasomotor reflex), goosebumps (pilomotor reflex), local skin oedema and some trophic changes such as dermatomal hair loss and cracking nails (Baldry 2001, Borg-Stein et al 2002, Gunn, 2007, Shah 2008).  73  Pathophysiology of chronic myofascial pain development Myofascial pain develops through two main pathways (muscular and neuropathic) that correspond well to the clinical picture of patient with LBP and CLBP.  Research investigating myofascial pain shows that direct injury and mechanical stress on muscle are the primary causes for myofascial pain (Baldry 2001). Trauma or abnormal stress causes affected muscle fibers to release excess intracellular calcium. This abnormal increase of calcium induces uncontrolled muscle fibers contraction, local circulation impairment and increased metabolism, resulting in the formation of muscle contracture (or taut band) and the activation of TrP (Hong et al 1998). Myofascial pain syndromes may also develop as consequence of peripheral neuropathy, for instance a radiculopathy in the context of a musculoskeletal disorder (Backonja 2003, Backonja et al 1998, Dworkin 2002, Hansson et al 2001, Latov 2007, Wheeler 2004). Any nerve root lesion or dysfunction at the level of the spine will lead to the development of peripheral neuropathy within few weeks with hypersensitivity in the innervated striated muscle (of neuropathic origin), creating muscular contracture (taut band) and TrP with referred pain: a typical myofascial pain syndrome (Cannon et al 1949; Gerwin 2001). Whatever the initial cause that leads to muscular contracture and TrP (muscular or secondary to a neurologic component), the muscle tension abnormalities cause local ischemia and the shortened muscles release endogenous substances such as bradykinin, prostaglandins and serotonin.  These substances activate muscle nociceptors which  cause deep muscle aching pain, muscle tenderness, muscle weakness and decrease in range of motion (Mense 2003, Mense et al 2001, Galluzzi 2007). Furthermore, sensitized muscle nociceptor endings release neuropeptides such as substance P and calcitonin gene-related peptide (CGRP) which lead to a cascade of events including the release of histamine, bradykinin, prostaglandins and serotonin (it is source of a self sustained process). These cumulative effects create local edema in muscle tissue that affects local circulation (Shah 2008). Furthermore, this rapid and intense discharge of sensory fibers (sensory afferent barrage) activates sympathetic preganglionic neurons on reaching the spinal cord and thus causes noradrenergic postganglionic neurons in sympathetic chain to  74  become activated. As a result, sympathetic efferent activity is being increased and causes the release of norepinephrine which is responsible for the autonomic phenomena (Jay 1995, Baldry 2001). Other studies have shown that activation of sympathetic preganglionic neurons participates in pain generation (Janig 1995, Janig et al 2001, 2003) through secretion of nerve growth factor (NGF) which drives local inflammation (Andreev et al 1995, Woolf et al 1996). Apart from peripheral muscle nociceptor sensitization, central sensitization at the spinal cord dorsal horn is also a factor in the myofascial pain mechanism (Hong et al 1998). When peripheral nociceptors are sensitized by injured muscles as described above, the high-threshold Group IV (C) afferents will fire at a lower threshold causing allodynia and central sensitization at the dorsal horn (Hoheisel et al 1993). Central sensitization induces deep somatic afferents to converge at synaptic connections with post-synaptic neurons at the dorsal horn resulting in the phenomenon of referred pain (Vecchiet et al 1999, Bahr et al 1981). It can also activate the release of substance P and N-methyl-D-aspartate (NMDA) which further enhances the synaptic connections at dorsal horn. This may account for the persistent pain when TrP is once activated (Shah 2008).  Few epidemiological studies document the high prevalence of myofascial pain syndrome in the context of chronic pain and CLBP. Fishbain et al. (1986) showed that among 283 chronic pain patients admitted to a pain center, 85% had their pain related to myofascial pain with TrP. Also, myofascial pain is frequently associated with chronic head, neck and back pain (Borg-Stein et al 2002, Simons 1988). In a study of 164 patients referred to a pain clinic with chronic head and neck pain, 55% were found to have myofascial pain (Friction et al 1985). In another study, Weiner (2006) showed that among 131 chronic low back pain patients, 95.5% of them had myofascial pain symptoms.  Myofascial pain is  believed to be one of the most common chronic pain syndromes that leads to disability and public health burden (Gerwin 2001, Weiner 2001).  Conventional treatments for controlling chronic myofascial pain: The American Pain Society (APS) recommends tricyclic antidepressants, benzodiazepines, gabapentin, and  75  opioids for severe chronic pain. However, clinical evidence demonstrated limited long-term efficacy and patients commonly experience side effects such as addiction, urinary retention, constipation, cardiac conduction block, dizziness, nausea, respiratory depression and orthostatic hypotension (Gilron et al 2006, Abram 2006, Dworkin et al 2003, van Tulder et al 2002).  A recent review of evidence from APS stated that  NSAIDs when compared to placebo showed significant difference in alleviating pain a week after treatment (Chou et al 2007) with no sign of long term effects. For benzodiazepines, a Cochrane review (2 high-quality trials) found tetrazepam to be associated with a greater likelihood of pain relief (RR, 0.71 [95% CI, 0.54-0.93]) and global improvement (RR, 0.63 [95% CI, 0.42-0.97]) compared to placebo, after 10 to 14 days (Cochrane Back Review Group 2003). A systematic review of antidepressants against placebo (9 trials) found a standardized mean difference (SMD) of 0.41 (CI, 0.22-0.61) for pain relief (Salerno et al 2002). Finally, a Cochrane review of opioids showed that tramadol was more effective than placebo for relieving pain SMD 0.71 (95% CI 0.39-1.02) and improving function, SMD 0.17 (95% CI 0.04-0.30) (Deshpande et al 2007), in the short term.  Most of pain studies have important limitations because it is  difficult to control for the use of co-medications and interventions to control pain. For instance when the outcome is the use of a pain score, it is very hard to take into account the use of co-interventions.  Most of studies do not provide any intervention regarding  the way they handle this issue that affect deeply the result’s credibility. In our proposal, we will use a “success-failure” outcome that enables integrating the pain score and the use of co-intervention to determine “success”.  Complementary and alternative medicine (CAM): Due to lack of long-term efficacy and potential adverse effects of conventional treatments, many patients use CAM. Official guidelines also recommend their use (Chou et al 2007). Common CAM therapies for chronic pain include exercise, spinal manipulation, massage, acupuncture, electrical nerve stimulation, laser therapy and intramuscular stimulation.  We will focus on needle  therapies and describe acupuncture and IMS deep needling therapy.  a) Traditional Chinese acupuncture is a dry needling technique that targets acupuncture 76  points on well defined meridians, which emphasize a smooth flow of Qi (vital energy) and homeostasis in human body. It has been practiced in China for thousands of years in reducing chronic pain and started to draw attention to western countries in the past decades. The acupuncturist after precise diagnosis of a TCM syndrome develops a treatment strategy that includes treatment of specific acupoints on specific organ meridians that circulate across the body and transfer energy (Qi) expressed through two forms, yin or yang. According to this theory, pain is often considered as consequence of a “Qi blockage”.  The treatment strategy consists of use of needles to remove the  identified blockage. Recent animal studies documented acupuncture’s mechanism of action. The needle activates proprioceptive Aβfibers which inhibit the input of small nociceptive C fibers (Gate Control Theory) (Moffet 2006, Abram 2006). The needle also stimulates Aδfibers which causes interneuron activation in the dorsal horn and the release of endogenous opioids and neurotransmitters (serotonine, gama-aminobutyric acid and acetylcholine), inhibiting intraspinal transmission of C fiber input (Moffet 2006, Cheung et al 2001). Finally, recent studies showed that acupuncture can modulate the sympathetic outflow and reduce sympathoexcitatory reflex responses (Li et al 1998, 2001, Dai et al 1992, Tjen-A-Looi et al 2003) with decrease of inflammation, thus reducing pain (review by Longhurst 2004). Clinical studies support the effect of acupuncture. One Cochrane review on chronic low back pain (8 trials) showed evidence supporting the short-term pain relief (3 months or less) and functional improvement of acupuncture, compared to no treatment or sham therapy (Furlan et al 2005). Two high quality trials showed that acupuncture was more effective than sham therapy with a weighted mean difference (WMD: sum of the differences weighted by individual variances) of -1.78 (95% CI: -2.55, -1.07). However, the pooled results (underpowered) from two high quality trials found that acupuncture was not significantly better than sham therapy in terms of intermediate-term pain relief, with a WMD -0.57 (95% CI: -1.47 to 0.33).  Therefore, the conclusion stated the need  for high-quality trials to better document the short term effect of acupuncture and to study long term effectiveness (Furlan et al 2005, Johnston et al 2008).  77  b) Other forms of needle therapies are also used with reported effects on managing chronic pain.  We will describe here two techniques that use dry needles at points of  palpable tenderness located in contracted muscle (i.e. the taut band of myofascial pain syndrome): “Ah Shi acupuncture” and Intramuscular stimulation (IMS).  Ah-Shi  acupuncture (Birch 2003, Hong 2000, Shah 2008, Mense et al 2001) and IMS (Gunn 1997, 2007; Ga 2007) have been used extensively in the domain of CMP. techniques practitioners insert needles into select contracted muscles.  In both  Needle in  contracted muscles works by creating a local twitch response in the muscle responsible for an extra contraction of muscle fibers. This contraction sensitizes reflex motor efferent activity or Golgi organs (proprioceptive sensory receptor organ that measures tension of muscle contraction) causing reflex relaxation and, hence, pain relief (Gunn et al 1985, Baldry 2001). In addition, the needle also activates all the mechanisms associated with classic meridian based acupuncture (described above). The main difference between Ah Shi acupuncture and IMS is the pathophysiological principles on which each is based. IMS considers that CMP is the consequence of peripheral neuropathy (mostly a radiculopathy in the context of low back pain) (Gunn 1997, 2007).  The technique  employed in IMS acupuncture is similar to that in Ah-Shi acupuncture, (practitioners insert needles deeply into contracted muscles), but treatment is applied to all associated spinous muscles at segmental levels according to the mechanism of an underlying pepipheral neuropathy. IMS theory is based on the fact that TrP and taut band at limbs and trunk are closely associated with the segmental distribution of lumbar radiculopathy at the back (Gunn 1997). When IMS practitioners treat chronic myofascial pain, they search carefully for the TrP and taut band, as well as signs of peripheral neuropathy (autonomic symptoms for instance) and apply IMS treatment specifically on the regions of muscular contractions to induce the relaxation reflex (Gunn 2007). IMS may alleviate pain through three different mechanisms: (a) by relaxing contracted muscles; (b) by decreasing C fiber ectopic impulses from the injured nerve and (c) by inhibiting the sympathoexcitatory reflex (similar to acupuncture). Literature review regarding Ah-Shi acupuncture and IMS are poor and not conclusive. 1) We only found two small sham controlled studies assessing the effect of Ah-Shi  78  acupuncture; and we found several studies and one systematic review (Cummings et al 2001) comparing the respective effects of dry needling at TrP and injections of local anesthetic or botulinum toxin. The review reports that after the immediate effect of local injection (i.e. one week after the intervention), the trends observed support a possible effect of a dry needle intervention in the range of those observed with local injections. The authors strongly recommend conducting high quality trials against sham control, with sufficient power and enough duration (Cummings et al 2001). 2) Two studies have been conducted to assess IMS efficacy. Ga et al (2007) showed that among 43 patients with chronic MPS in the upper trapezius muscle, IMS was equivalent in reducing pain intensity to lidocaine 0.5% injection at 1-month follow-up. An unblinded trial by Gunn (1980) involved 53 patients with chronic low back pain. Both treatment and control groups followed a standard regimen of physiotherapy, remedial exercises and occupational therapy while subjects in treatment groups also received IMS twice a week. In the IMS treatment group 62% of patients returned to their original work and 34% shifted to a lighter employment while in the control group only 15% of patients returned to their original work and half of these worked in a lighter employment.  In the last 12  months we conducted a cohort study of all patients treated by IMS at one clinic in Vancouver. We found that the success rate (at least one point deduction in 0-11 average pain scale) was 55% for patients who had received their fourth IMS treatments and the mean change in worst pain score was -1.09 (95% CI:-1.69, -0.50). We have also conducted an inter-rater reliability test to test the consistency among IMS practitioners in identifying taut bands, good consistency was found in identifying the number of taut bands at spine levels; we are still working with the team to improve diagnosis consistency. Despite absence of solid evidence, the IMS technique is widely used in Canada and worldwide for treating myofascial pain and neuropathic pain.  Because IMS therapy  takes a broader approach than Ah-Shi acupuncture (by treating spine segmental level) while sharing the same technical approach, we decided to use IMS as second intervention in our project to compare it to acupuncture and sham needling.  8.3 Rationale Overall, CLBP is an important health problem; difficult to treat and responsible for an 79  enormous burden for patients and society. There is evidence that classic acupuncture and other needle therapies developed specifically to control myofascial pain may work to decrease pain in CLBP patients, but these techniques have not been compared against each other and they both still need to be compared to sham treatment to assess clearly the importance of the effect and its duration.  Our proposal aims to compare the  effectiveness of classic acupuncture and IMS needle therapy against sham needle, for pain management.  Because our project is conducted by an independent team of  investigator with the participation of excellent acupuncturists and IMS practitioners, it represents a unique opportunity to provide an answer to this important question that has significant public health implications.  Other features of our proposal are a) the use of a  “success-failure” outcome that is more likely to generate valid results and b) long term follow-up using administrative databases.  8.4 Clinical Relevance The trial results, either positive or negative, will be useful to inform patients and practitioners.  If the results are positive regarding IMS or acupuncture against sham,  more patients may then look for these treatments and get benefits. If the results are different between IMS and acupuncture, in particular with regard to the presence of chronic myofascial pain syndrome, the information will be very useful to guide patients. Positive results may also lead to the development of a stronger research stream in a very important domain of therapeutic care that is frequently used by patients, and remains largely neglected by researchers.  If the results do not show any benefit above sham  needle, this information will also be useful to publish to inform practitioners and patients. Trial results therefore, whatever the results’ direction will be published in peer review journals and also in large public dissemination journals. interviews and media presentations (radio and TV).  Diffusion will include  Scientific results will be presented  at the Canadian Pain Society and other International societies. These societies are well attended by pain specialists and also by patients.  Presenting results in public forums  will have a large impact for the diffusion of the results. Dr M Chung will practice acupuncture in our study; as VP of the BC College of Chinese Medicine and Acupuncture he will facilitate the diffusion of the results in the community of acupuncturists in BC and  80  Canada,  8.5 Study Objectives Primary objective is to assess whether IMS or acupuncture intervention demonstrates greater benefits than sham needling in reducing pain intensity in patients with chronic low back pain 6 months after the end of the intervention. Secondary objectives are 1) to assess whether IMS or acupuncture intervention can decrease the consequences of chronic low back pain on disability and quality of life compared to sham needling; 2) to compare the effect of IMS and acupuncture intervention in reducing pain and pain consequences; 3) to study the effect of the two needling strategies up to 12 months after the end of the intervention.  8.6 Study Hypothesis We expect both IMS and acupuncture showing more benefits in reducing chronic pain compared to sham acupuncture. We expect the effect size of IMS in reducing pain intensity to be higher than that of acupuncture.  8.7 Study Design This is a single (subjects) blind RCT and it is conducted by a research team that is independent from the clinicians who practice IMS or acupuncture. Participants with CLBP, who meet the inclusion and exclusion criteria, will be recruited and randomly allocated to IMS, acupuncture or sham acupuncture. Interventions will be carried out once or twice a week for a maximum of 8 weeks and 12 sessions. This combination of fixed time for the intervention (8 weeks) and up to 12 sessions has been decided after discussion with the needle specialists as covering all situations in which effect will be observed; following longer and offering more sessions is possible – but it is for cases that are relatively resistant to the treatment. Baseline full assessment will be conducted before the first intervention and the same assessment will be conducted at the end of the study intervention (after 8 weeks) or whenever subjects to interrupt the treatment. The long term effect will be assessed by phone interviews conducted 3, 6, 9, 12 months after the study intervention. Long term effect and overall impact on health services use will be  81  assessed using BC administrative databases. During the intervention period, subjects will also undergo simple pain intensity assessment before each new session. All assessments will be conducted by a research team member who is unaware of the nature of the intervention.  8.8 Sample Specification Our target population is subjects with CLBP defined as pain and muscle tension/stiffness located in the lower lumbar spine corresponding to L1 and below. In practice: below costal margin and above the inferior gluteal folds (Dworkin 2002, Stephen 2006, van Tulder et al 2002) that persisted for at least 6 months.  We will consider that duration is  ≥ 6 months if, at the time of inclusion the date of the first pain treatment is ≥ 6 months AND there has been no period longer than 1 month without pain in the same area.  Age  lower limit is 18 years without upper limit. Exclusion Criteria: Š  Patients with low back pain of less than 6 months duration  Š  If the “Average Pain” on the Brief Pain Inventory scale is < 4 at inclusion  Š  Patients who have pain from other origins: spinal cord injury, rheumatic disease, fibromyalgia, neuropathic pain from central origin. Patients with “secondary” myofascial syndrome due to serious diseases (like cancer, metabolic disease, diabetic neuropathy)  Š  Patients who received IMS or acupuncture treatment previously for the same reason  Š  Patients who are off work for over 3 months due to injury, those receiving disability payments  Š  Patients who have serious bleeding tendencies  Š  Patients with another serious condition that may (a) interfere with normal follow up (eg. cancer, serious kidney disease, Alzheimer Disease), (b) be the source of pain (eg. severe migraine) or (c) may affect quality of life or be source of disability (eg. Parkinson Disease).  82  8.9 Interventions 8.9.1  IMS Intervention  IMS is administered by certified IMS practitioners. Sterile stainless steel acupuncture needles are used and are not re-used. 30 gauge or finer needles are used depending on severity of muscle contraction. Needles are mainly 2-3 inches in length. Needles are deeply inserted into muscle taut bands and associated spinous muscles along the spine. Needles will remain in the muscle for 10 to 20 minutes and will be twisted from time to time to induce the reflex.  8.9.2  Acupuncture Intervention  Acupuncture is performed by certified acupuncturists. Sterile stainless steel acupuncture needles are used and are not re-used. 30 gauge or finer needles are used depending on severity of muscle contraction. Needles are mainly 2-3 inches in length. Needles are deeply inserted into acupoints on meridians BL, GB and KI that are often applied in treating low back pain. In our study, needles will remain in place for a similar amount of time to that of IMS intervention and all practitioners will be trained to provide the same type of care to all patients.  8.9.3  Sham Intervention  The control for acupuncture will be placebo acupuncture needle designed and published by our collaborator Takakura of the Japan School of Acupuncture, Moxibustion and Physiotherapy at Hanada College. The placebo needles are shorter and blunt versions of acupuncture needles approved for sale and readily available in Canada.  Guidelines are  in place to ensure quality and sterilization in accordance with Good Manufacturing Procedure. Two validation studies have been conducted and published for these placebo needles.  Of the 120 needles (60 real needles, and 60 placebo needles), the patients  identified 65(54.2%) correctly (penetrating needle = 35, non-penetrating needle = 30) and 55 (45.8%) incorrectly (penetrating needle = 25, non-penetrating needle = 30), which fits a probability of 0.5 (χ2 = 0.833, p = 0.361) (Takakura et al 2007, 2008).  Further  validation test will be conducted at the end of this study by surveying the subjects’ opinions of which intervention groups they have been assigned to. In our study, needles  83  will remain in place for a similar amount of time to that of IMS and acupuncture intervention and practitioners will be trained to provide the same type of care to all patients.  8.9.4  Co-medications and Complementary Interventions  During the study, all subjects will be informed (a) to undergo periods of stretching twice a day – according to precise instructions (b) to keep their drug treatment stable, (b) to not add any new drugs, and (c) to not use other alternative medicine.  This information will  be collected regularly during the trial and used in the analysis.  8.10  Allocation of Intervention  8.10.1  Methods for Randomization and Stratification  Participants who meet the inclusion and exclusion criteria and who have signed the consent form will be randomized after recording baseline information.  Randomization  will be stratified based on intensity of the myofascial pain syndrome (number of TrP </= 3 or >3) and duration of pain (6 months to 2 years or >2 years). Subject allocation will be based on sequence of computer-generated random numbers with blocks of size 3 to control tightly the allocation balance within each stratum. Access to the randomization list will be through a web-based system that enables online interactive checking of the inclusion/exclusion criteria before authorizing random allocation. The trial coordinator will initiate the randomization process and transmit the information to the practitioners who conduct the intervention.  8.10.2 Methods for Minimization of Bias Randomization and concealment of allocation protects against selection bias. Blinding patients and interviewers to the nature of the intervention ensures protection against performance and detection biases. Practitioners cannot be blind; however, (a) they will not be involved in collecting information from patients and (b) they will be trained to provide the best care to all patients: interaction, discussion, explanation and needling duration (the duration of the intervention will be monitored). All patients will be treated in one clinic – therefore, after randomization subjects will go with the practitioner who is  84  in charge of the intervention.  Sham acupuncture will replicate the IMS needle.  Results of physical examination and strategic treatment plan will be recorded. The whole process of making diagnosis and developing IMS treatment strategy has already been assessed and showed very good consistency at segmental level and we are working with team to increase consistency at muscular level. Interviewers from the research team will be blinded to avoid any detection bias. They will use standard questionnaires and adhere to strict interview processes. Attrition bias is protected by telephone contact that minimizes loss-to-follow-up. Moreover, use of administrative databases will help organizing long term follow-up in a rigorous and unbiased manner.  The  lost-to-follow-up procedure will involve phoning patients who fail to attend a session or a follow up visit, to determine the reason and to collect minimum information regarding pain intensity (primary outcome). During the study patients will be asked not to try acupuncture or other types of complementary medicine (TENS, massage) and to keep their drug treatment stable; drug use and co-interventions will be recorded precisely at each treatment visit.  8.11  Treatment Duration  The duration of the intervention may vary from one patient to another in relation to the treatment efficacy – for a maximum of 12 sessions, offered during an 8 week period. Treatment is interrupted when pain disappears or when patients and practitioners do not see any improvement after three consecutive sessions (criterion for the study) because the maximum gain is considered to have been achieved.  The maximum treatment duration  for this study will be 8 weeks with one to two sessions per week (8 to 12 needle sessions). If patients have to leave the study for one week or two, the time lost will be recuperated when they return to accommodate the 12 sessions.  8.12  Frequency and Duration of Follow-up  Follow-up will start at the end of the treatment period: patients will be examined and interviewed at the end of the intervention (8 weeks for most patients); they and will be interviewed by telephone at 3-month, 6-month, 9-month and 1 year after the end of interventions.  The whole set of outcomes (type of pain, disability and quality of life)  85  will be assessed at each follow-up contact. A diary will be given to the patients at the end of the intervention to collect information regarding degree of pain, functional limitations, use of pain medications and alternative treatments. We will also use administrative databases to compare the use profiles regarding drugs and other health services (physiotherapy, medical consultation) before and after interventions in the three groups.  8.13  Outcome Assessment  8.13.1  Types of Outcomes  The primary outcome will be assessed 6 months after the end of intervention using a “Success-Failure” outcome that includes information on pain control and the use of co-interventions. “Success” will be defined for each patient if (i) average pain score (BPI scale) is decreased by 1 unit compared to baseline assessment and (ii) the amount and types of analgesic drugs is the same or reduced and (iii) no other pain management device or strategy has been used. Otherwise, the intervention will be considered “failure”. Acupuncture and IMS consolidation treatment after the 8 week intervention is expected and will be recorded – it will not considered a treatment failure.  For the intention to  treat analysis, patients who do not complete follow-up will also be considered “failure”. The Brief Pain Inventory (BPI) will be used to assess pain; this scale is the most widely used to assess severity and impact of pain on daily function (Cleeland et al 1994). Each question is measured on a numerical rating scale ranging from 0 (no pain at all/no interference) to 10 (pain as bad as you can imagine/complete interference). BPI has been validated for the consistency, reliability and sensitivity of severity of pain and impact of pain.  We will use BPI-Q1 “Average Pain in the last week” for the determination of  “success” the primary outcome because it is the most relevant question for people who suffer from chronic pain. Secondary outcomes include other measures of pain (i.e. other pain scales in BPI), pain consequences (disability, quality of life) and adverse events: a) Other pain intensity scales on BPI include “Worst pain in last weak”, “least pain in the last week”, and “pain right now”. b) Question 5 of BPI assesses the level of pain interference in seven domains: general activities, mood, walking ability, normal work, relations with other people, sleep and  86  enjoyment of life. Each question is measured on a numerical Likert rating scale ranging from 0 (no pain at all/no interference) to 10 (pain as bad as you can imagine/complete interference). c) Change in disability will be assessed using the Oswestry Low-Back Pain Disability Index (ODI) (Fairbank et al 1980). The ODI consists of ten questions on activities of daily living which include personal care, lifting, walking, sitting, standing, sleeping, sex life, social life and traveling. It is one of the most commonly used questionnaires to assess degree of disability for back pain and has demonstrated good reliability, validity, and responsiveness (Fairbank et al 1980, Kumar et al 2007, Turk et al 2001). Among all randomized controlled trials that evaluate LBP, nearly 59% of them use ODI to assess the disability functioning of LBP patients (Hammill et al 2008). d) Change in quality of life will be assessed using Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36v2) (Ware et al 1993). SF-36v2 is a well-validated measure of generic quality of life that has been used extensively in many conditions, including chronic pain. It has eight subscales that can be analyzed separately (physical functioning, role physical, bodily pain, general health, vitality, social function and role emotional) and two summary scales: Physical and Mental. e) Change in anxiety and depression will be assessed using the Hospital Anxiety and Depression Scale (HADS). HADS has been widely used worldwide. Its psychometric qualities have been documented in both hospitalized and primary care patients and in the general population (Bjelland et al 2002, Herrmann 1997). The HADS consists of fourteen questions, seven to derive an anxiety score (HADS-A) and seven to derive a depression score (HADS-D). Scores can be interpreted as follow: 0-7 normal, 8-10 =borderline/mild, 11-14 =moderate, and 15-21 =severe (Schipper et al 1990). It will be used as an outcome (because reduction of pain should improve depression) and also as a predictor as patients with depression may have more difficulty to improve. f) Use of drugs and health services by patients before the intervention and after is an important objective outcome to assess the overall effect of the intervention. British Columbia has an excellent set of databases to describe drug prescription (Pharmanet) and use of health services (Medical Service Plan data base (MSP).  The primary  investigator (JPC) has already been funded by CIHR (PI is S Amed) for the use of  87  these databases to assess quality performance in treating diabetic patients in BC (June 2009; #193166). g) Adverse events (AE) will be recorded systematically on a weekly basis when patients attend the treatment sessions using standard AE drug trials form. Serious adverse events will be recorded and described according to special procedures.  8.13.2  Methods of Outcome Assessment  Outcome measurement will be made by research team members who do not know the treatment allocation and are well-trained to keep the standard of interview homogeneous which minimizes detection bias. The whole set of outcomes (pain intensity, disability, quality of life) will be assessed at baseline and at the end of treatment (whenever it happens). It will also be assessed at 3-month, 6-month, 9-month and 1 year after the termination of treatment by telephone interview. During the treatment period, pain intensity will be assessed by interview before each treatment session (short assessment using BPI). A diary will be given to the patients at the end of the intervention to help keeping track of adverse events and pain management strategies. Patients who fail to attend a treatment session and those who do not come to a visit will be contacted by phone to reschedule an appointment or, if patients cannot come, to collect the minimum useful information regarding the main outcomes and the reason for not attending the scheduled visit.  Information from BC  administrative databases will be related to drug and other health services use.  8.14  Recruitment  Recruitment should not be a problem because chronic low back pain is a frequently occurring condition and the sample size is not too large. Patients will be recruited from several pain clinics in Vancouver (each of them has an acupuncturist) and through newspaper advertisement. All pain clinics have a long list of patients waiting to see the clinicians; they also have a list of patients whose pain does not improve despite all conventional treatments: We will try to have access to these populations.  Interested  patients will receive a consent form and will be given enough time to decide upon participation. After signing the consent form patients will be examined to confirm the  88  diagnosis and verify all eligibility criteria. Patients who meet the study inclusion criteria will then be randomized to one of the three groups.  8.15  Retention Strategy  Some people may limit the number of insertions during a treatment session due to initial pain associated with insertion into contracted muscles. We will keep close contact with patients who come once a week at the clinic during the treatment phase to keep compliance and may adjust number of insertions. Also, patients will receive travel compensation and free parking when they come to receive treatments. Follow-up assessment is conducted by telephone which is easy and straight forward.  Patients who  discontinue follow-up will be considered “failure” for the main outcome.  Finally using  administrative databases is a very secure way to guarantee systematic follow-up of all patients included.  8.16  Sample Size  We estimated the acupuncture effect size from several good quality studies comparing acupuncture to sham needles (Kerr et al 2003, Leiging et al 2002, Mendelson et al 1983, Molsberger et al 2002): WMD of pain improvement was 1.02 with standard deviation around 2.5.  We then considered that about 15% of patients in the sham treatment group  would meet the “success” criterion. If the success rate in the intervention groups is 45% we need to include 43 patients in each group to have 80% power to find such a difference significant (alpha=0.025).  55% success is the rate we found after one month of  treatment by IMS practitioners. Considering possible 10% withdrawal, total of 150 patients will be involved (50 in each arm).  Such a sample size gives comfortable power  to assess all the continuous outcomes variables (mean differences in pain score, disability or quality of life).  8.17  Statistical Analysis  Initially, we will examine the distributional characteristics of all variables graphically and provide basic summary statistics. Analysis will be based on intention to treat approach. The primary analysis will be the comparison between number of success and failure  89  using chi-square test. Logistic regression will also be used to adjust for important covariates (such as: initial pain score, duration of pain, gender, drug medications). Secondary analysis will be on comparing the changes in pain intensity between groups at baseline and follow-up (Average Pain, Worst Pain).  T-test will be used for all  continuous variables and then the analysis of covariance (ANCOVA) model to adjust for important covariates. Other pain questions will also be studied (e.g. Least Pain during last week) and the analysis will take into account the multiple outcomes to prevent false conclusion: p-values will be adjusted and results will mention the number of outcomes. Note the sample size calculation already takes into account the fact that two active treatments will be compared to one sham intervention through the use of Bonferroni correction. To accommodate loss to follow-up, we will model serial measurements using a linear mixed model approach. The model will include some baseline variables which are clinically relevant or which show association with the occurrence of incomplete follow-up, as per current recommendations (Geert et al, 2004).  Side effects  will be described (organ classification) and comparisons will be made between groups. Per protocol analyses will also be conducted after eliminating subjects who used co-medications, or provided incomplete follow up.  Along this line, sensitivity analyses  may be conducted to assess the impact of missing information according to different scenario. Subgroup analyses will be exploratory to check possible difference in effects according to previous duration of pain, gender, and number of segments involved.  8.18  Trial Management  8.18.1  Initiating Interventions Strategy  All interventions will take place at one clinic. As a block of size 6 will be used in subject allocation in this study, interventions will start whenever there are 6 patients enrolled in the study. IMS practitioners, acupuncturists and sham needling practitioners will then be notified the date of intervention. At the clinic, each patient will receive intervention in a closed room where there is only the patient and practitioner present in the room. Patients will finish questionnaire in a waiting area with the presence of research coordinator who is unaware of subject allocation. After each intervention, patients will be asked to come again to receive the next session of intervention in the subsequent week until the end of  90  all sessions. Time can be scheduled with practitioners whenever they are free to come to the clinic.  8.18.2  Data Collection and Management  The trial will be managed by the Clinical Research Support Unit at BC Children’s Hospital that has huge experience in conducting clinical trials with full respect of ethics and regulation regarding confidentiality and privacy and ICH-GCP guidelines.  This  team has already conducted intervention on traditional Chinese medicine. Initial contact with patients will be made at the pain clinic and, if interested they will contact the study coordinator who will share time between BC Children’s Hospital and the study site (one acupuncture clinic); she will inform patients and collect consent.  She will then  randomize patients using the Dacima on line system and organize the intervention. Baseline and post intervention assessments will be organized by the coordinator using questionnaires that most patients can complete without help after careful instructions. Telephone interviews will be collected by the research coordinator at specific time. Information will be entered (double entry procedure) into the electronic system with online edit check and quality control.  Quality assurance will also be reinforced using  automated real time reports (meta-data) to help managing the study and identifying problems in a timely way.  Database will be located on a server at the Research Institute  with high level protection and restricted access to the research team only. information and questionnaires will be stored in a locked filing cabinet.  All  Study audits  will be conducted regularly to ensure full respect of protocol throughout the study.  A  steering committee involves all co-applicants as well as the data Manager at BCCH and the research coordinator.  Adverse events will be recoded according to specific  procedures; the Principal Investigator will review them regularly and present them to the Steering Committee.  8.18.3  Safety Monitoring and Adverse Events  IMS is a safe intervention. Patients may experience feeling of pain as needles inserted to muscle trigger points and they may bleed a little at the needle insertion points (White et al 2001, Ernst et al 2001). Side effects will be reviewed regularly by the Principal  91  Investigator and presented to the Research Committee. Serious Adverse Event (SAE) will be recorded and reported according to GCP standard procedures, decision of code breaking will be determined by Principal Investigator.  8.18.4  Role of Principal Applicant and Co-applicant  Principal applicant, Dr Jean-Paul Collet, is professor of Pediatrics and Epidemiology at UBC. He has huge experience in conducting clinical trials and has published several articles regarding neuropathic pain. Dr Collet will oversee the whole study, ensuring strict adherence to study procedures and making daily management decisions. Dr Millan Patel, though he has no direct expertise in pain research, will contribute his thorough knowledge of the sympathetic nervous system (SNS). He has extensive experience studying the SNS in mice through genetic, pharmacologic and anatomic means. Dr Marc White is the founder and executive director of the Canadian Institute for the Relief of Pain and Disability (CIRPD). CIRPD will assist with patient recruitment. Dr White’s academic focus is on knowledge translation and knowledge mobilization and will assist with dissemination activities congruent with the importance of the findings. Dr Rollin Brant is a senior statistician and professor in the Department of Statistics at UBC. His collaboration as a biostatistician is critical for the analysis and will help in making important decisions. All co-applicants will be responsible for reviewing protocol and reports.  Our team also includes experienced acupuncturist (Dr M Chung from the  College of acupuncturist and Chinese medicine in BC) and IMS practitioners (Dr Gunn and Dr Lam) which is essential for the success of the study.  8.18.5  Steering Committee  The trial steering committee involves all co-applicants as well as the data Manager at BCCH: Victor Espinosa and the research coordinator.  There is no data safety and  monitoring committee in this study but the adverse events will be recoded according to specific procedures and the Principal Investigator will review them regularly and present them to the Steering Committee.  92  8.19  Ethics  This study proposal and all study related materials including consent forms, questionnaires will be submitted to UBC Clinical Research Ethics Board for ethical approval.  8.20  Budget  The budget for the first year study is estimated to be CAD$116,100.  93  BIBLIOGRAPHY Abram SE. Pain Medicine: The Requistes in Anesthesiology. Elsevier. 2006 Aker PD, Gross Ar, Goldsmith CH et al. Conservative management of mechanical neck pain: systematic overview and meta-analysis. 1996; 313:1291-1296 Al Obaidi SM, Al Zoabi B, Al Shuwaie N, Al Zaabie N, Nelson RM. The influence of pain and pain-related fear and disability beliefs on walking velocity in chronic low back pain. 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Acta Pshychiatrica Scandinavica 1983;67:361-370  110  APPENDIX A: ADDITIONAL TABLES Innervating segments in upper extremity muscles Innervated Muscles Segmental Levels abductor brevis C6 C7 C8 T1 abductor digiti minimi C6 C7 C8 T1 abductor pollicis C6 C7 C8 T1 adductor pollicis C8 T1 biceps brachii C5 C6 brachialis C5 C6 brachioradialis C5 C6 coracobrachialis C5 C6 C7 C8 deltoid C4 C5 C6 C7 dorsal interossei C8 T1 extensor carpi radialis C5 C6 C7 C8 extensor carpi ulnaris C6 C7 C8 extensor digiti minimi C6 C7 C8 T1 extensor digitorum C6 C7 C8 extensor indicis C6 C7 C8 T1 extensor pollicis brevis C6 C7 C8 extensor pollicis longus C6 C7 C8 T1 flexor carpi radialis C6 C7 C8 flexor carpi ulnaris C7 C8 T1 flexor digiti minimi C6 C7 C8 T1 flexor digitorum C6 C7 C8 T1 flexor pollicis brevis C6 C7 C8 T1 flexor pollicis longus C6 C7 C8 T1 infraspinatus C4 C5 C6 latissimus dorsi C6 C7 C8 levator scapulae C3 C4 lumbricales C6 C7 C8 T1 opponens digit minimi C7 C8 T1 opponens pollicis C6 C7 C8 T1 palmar interossei C8 T1 palmaris longus C6 C7 C8 T1 pectoralis major C6 C7 C8 T1 pectoralis minor C8 T1 pronator quadratus C6 C7 C8 T1 pronator teres C5 C6 C7 rhomboid major C4 C5 C6 rhomboid minor C4 C5 C6 serratus anterior C5 C6 C7C8 supinator C5 C6 C7 supraspinatus C4 C5 C6 teres major C5 C6 C7 111  Innervating segments in upper extremity muscles (continue) Innervated Muscles Segmental Levels teres minor C4 C5 C6 C7 trapezius C3 C4 triceps brachii C6 C7 C8  Innervating segments in lower extremity muscles Innervated Muscles Segmental Levels adductor brevis L2 L3 L4 L5 adductor longus L2 L3 L4 adductor magnus L2 L3 L4 L5 biceps femoris L4 L5 S1 S2 S3 dorsal interossei S1 S2 extensor digitorum brevis L4 L5 S1 S2 extensor digitorum longus L4 L5 S1 S2 extensor hallucis brevis L4 L5 S1 S2 extensor hallucis longus L4 L5 S1 S2 flexor digitorum brevis L5 S1 flexor digitorum longus L4 L5 S1 S2 S3 flexor hallucis L5 S1 gastrocnemius L4 L5 S1 S2 S3 gluteus maximus L4 L5 S1 S2 S3 gluteus medius L4 L5 S1 S2 gluteus minimus L4 L5 S1 gracilis L2 L3 L4 L5 pectineus L2 L3 L4 peroneus brevis L4 L5 S1 S2 peroneus longus L4 L5 S1 S2 piriformis S1 S2 S3 quadratus femoris L4 L5 S1 rectus femoris L2 L3 L4 L5 sartorius L2 L3 L4 semimembranosus L4 L5 S1 S2 S3 semitendinosus L5 S1 soleus L4 L5 S1 S2 S3 tensor fascia lata L4 L5 S1 tibialis anterior L4 L5 S1 S2 tibialis posterior L4 L5 S1 S2 vastus lateralis L2 L3 L4 L5 vastus medialis L2 L3 L4 L5 vastus intermedius L2 L3 L4 L5  112  APPENDIX B: HUMAN ETHICS APPROVAL CERTIFICATE  113  114  115  

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