Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Submaximal measures of cardiovascular fitness in individuals with spinal cord injury Hol, Adrienne Theresa 2006

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-ubc_2006-0052.pdf [ 5.1MB ]
Metadata
JSON: 831-1.0092474.json
JSON-LD: 831-1.0092474-ld.json
RDF/XML (Pretty): 831-1.0092474-rdf.xml
RDF/JSON: 831-1.0092474-rdf.json
Turtle: 831-1.0092474-turtle.txt
N-Triples: 831-1.0092474-rdf-ntriples.txt
Original Record: 831-1.0092474-source.json
Full Text
831-1.0092474-fulltext.txt
Citation
831-1.0092474.ris

Full Text

SUBMAXIMAL MEASURES OF CARDIOVASCULAR FITNESS IN INDIVIDUALS WITH SPINAL CORD INJURY by A D R I E N N E T H E R E S A H O L B.Sc. (Kinesiology), University of Waterloo, 2003 A THESIS S U B M I T T E D I N P A R T I A L F U L F I L M E N T OF T H E R E Q U I R E M E N T S F O R T H E D E G R E E O F M A S T E R O F S C I E N C E in T H E F A C U L T Y O F G R A D U A T E S T U D I E S Rehabilitation Sciences T H E U N I V E R S I T Y O F B R I T I S H C O L U M B I A November 2005 © Adrienne Theresa Ho i , 2005 ABSTRACT Background: The prevalence of cardiovascular disease in individuals with spinal cord injury (SCI) is as high as or greater than in the general population, yet assessment of cardiovascular fitness rarely occurs in individuals with SCI. Purpose: 1) To review current literature and develop guidelines to assist clinicians in choosing appropriate submaximal tests for the evaluation of cardiovascular fitness in individuals with SCI; 2) to design a submaximal single-stage arm ergometer test (SSSAET) for use in individuals with SCI; and 3) to determine the test-retest reliability and criterion validity o f this exercise test. Methods: A systematic review o f the literature was done to identify and evaluate arm exercise tests that submaximally measure cardiovascular fitness in individuals with SCI. To evaluate the S S S A E T , 30 subjects with SCI were assessed using the American Spinal Injury Association (ASIA) scale, isometric strength testing, a physical activity questionnaire, the S S S A E T , and a VC^peak test. Test-retest reliability of the S S S A E T was determined by having subjects complete the S S S A E T on two days, separated by one week. Criterion validity was determined by comparing the results from the S S S A E T with the V02peak test. Results: The literature review identified six submaximal arm exercise tests for measuring cardiovascular fitness in individuals with SCI, but all tests featured limitations that prevented widespread clinical use. Test-retest reliability of the S S S A E T was excellent (ICC=0.81-0.90). A s well , correlations between VG"2peak and outcomes o f the S S S A E T ranged from r=0.63-0.92, indicating good to excellent criterion validity. i i Conclusions: Clinical recommendations were provided for the existing arm exercise test protocols. Testing showed that the S S S A E T has acceptable test-retest reliability and criterion validity, however further research is necessary before the S S S A E T w i l l be ready for implementation as a clinical tool to assess baseline and changes in cardiovascular fitness in individuals with SCI. 111 TABLE OF CONTENTS Abstract • » Table of Contents iv List of Tables v i List o f Figures • • • .-..vii List o f Abbreviations ; • • • • v i i i Acknowledgements - ix Chapter 1: Introduction - 1 1.1 Introduction ••••1 1.2 Selected exercise physiology concepts 3 1.2.1 Cardiovascular fitness, cardiac output and oxygen consumption 3 1.2.2 Heart rate 4 1.2.3 Power output 4 1.2.4 Oxygen consumption - power relationship 5 1.2.5 Oxygen consumption - heart rate relationship 6 1.2.6 Heart rate - power relationship 7 1.2.7 Blood lactate 9 1.3 Pathophysiology of SCI 10 1.3.1 SCI and motor system dysfunction 10 1.3.2 SCI and sympathetic nervous system dysfunction 11 1.3.3 Exercise implications 11 1.4 Purpose 13 1.5 Research questions and hypotheses 13 1.5.1 Research question 1 13 1.5.2 Research question 2 13 Chapter 2: A systematic review of submaximal exercise tests for individuals with spinal cord injury 14 2.1 Abstract 14 2.2 Introduction 15 2.3 Methods 18 2.3.1 Search strategy 19 2.4 Results 20 2.4.1 Predictive tests 20 2.4.2 Performance based tests 23 2.5 Discussion 24 2.5.1 Recommendations 28 2.6 Summary 29 Chapter 3: Reliability and validity of a submaximal arm ergometer test for the evaluation of cardiovascular fitness in individuals with spinal cord injury 34 3.1 Abstract 34 3.2 Introduction 36 3.3 Methods 38 3.3.1 Subjects 38 3.3.2 Protocol 40 i v 3.3.3 Data analysis 43 3.4 Results 44 3.4.1 Peak oxygen consumption 46 3.4.2 S S S A E T 46 3.5 Discussion 53 3.6 Summary 58 Chapter 4: General Discussion 59 4.1 Overview 59 4.2 Evaluation of the S S S A E T 59 4.3 Clinical implications 61 4.3.1 Limitations 62 4.4 Suggested future work 64 4.5 Summary 65 References 66 Appendices A Systematic review search strategy 77 B Recruitment advertisements 78 C Physical Activity Readiness Questionnaire 80 D Consent form 81 E Sample size calculation 87 F Cognitive Capacity Screening Evaluation '. 88 G A S I A classification of spinal cord injury 91 H Physical Activity Scale for Individuals with Physical Disabilities 93 I Strength testing - positioning and data collection 98 J Borg's Rating of Perceived Exertion Scale 99 K Blood lactate measurement protocol 100 L Electrode placement for E C G leads 101 M V0 2 peak protocol 102 N Psychometric properties of outcome measures 104 O Selected results-with subjects presented as two groups (paraplegia/tetraplegia).. 106 v LIST OF TABLES Table 2.1 Submaximal exercise tests 30 Table 3.1 Wheeled mobility categories ,'. .....41 Table 3.2 Subject characteristics 45 Table 3.3 Subject lesion levels (number per level) . . . . . . . . . . . . . . . 45 Table 3.4 Values during the VChpeak test 47 Table 3.5 Steady state values during the S S S A E T 47 Table 3.6 Test-retest reliability of H R and V O z .. - 50 v i LIST OF FIGURES Figure 1.1 Relationship between VO2 and PO: Linear increase with a ramp protocol (dashed line), "staircase" effect seen when P O increases i n three minute stages (solid line) 6 Figure 1.2 Change in VO2 during the transition from rest to submaximal exercise at a constant P O 6 Figure 1.3 Linear relationship between H R and VO2 for two individuals with different cardiovascular fitness levels 7 Figure 1.4 Linear relationship between H R and P O for two individuals with different cardiovascular fitness levels , 8 Figure 1.5 H R response to six minutes of submaximal steady state exercise at the same constant P O for two individuals with different cardiovascular fitness levels 9 Figure 3.1 Scatter-plot comparing H R during S S S A E T test 1 and test 2 49 Figure 3.2 Scatter-plot comparing VO2 during S S S A E T test 1 and test 2 49 Figure 3.3 Bland Altman plot of difference in S S S A E T H R between time 1 and time 2 versus average H R from time 1 and time 2 50 Figure 3.4 Bland Altman plot of difference in S S S A E T V 0 2 between time 1 and time 2 versus average VO2 from time 1 and time 2 50 Figure 3.5 Scatter-plot comparing V 0 2 during the S S S A E T and V0 2 peak (r=0.92) 51 Figure 3.6 Scatter-plot comparing P O during the S S S A E T and V0 2 peak (r=0.73) 52 Figure 3.7 Scatter-plot comparing H R during the S S S A E T and V02peak (r=0.63) 52 Figure 3.8 S S S A E T P O selection algorithm for individuals with tetraplegia 56 Figure 3.9 S S S A E T P O selection algorithm for individuals with paraplegia 57 vi i LIST OF ABBREVIATIONS A C S M - American College o f Sports Medicine A S I A - American Spinal Injury Association B P - Blood pressure C A D - Coronary artery disease C A F T - Canadian Aerobic Fitness Test C C S E - Cognitive capacity screening examination CI — Confidence interval C I N A H L - Cumulative Index to Nursing and Al l i ed Health Literature C S T F - Canadian Standardized Test of Fitness E C G - Electrocardiogram E M B A S E - Excerpta Medica H R - Heart rate ICC - Intraclass correlation coefficient L/min - Litres o f oxygen per minute mL/kg/min - Millili tres of oxygen per kilogram body mass per minute P A S I P D - Physical Activity Scale for Individuals with Physical Disabilities P O - Power output R E R — Respiratory exchange ratio R P E - Rate of perceived exertion SCI - Spinal cord injury SD - Standard deviation S E E — Standard error of estimate S E M - Standard error of measurement S S S A E T - Submaximal single-stage arm ergometer test V"E - Ventilation VO2 - Oxygen consumption V02peak - Peak oxygen consumption W - Watts ACKNOWLEDGEMENTS I would like to start by thanking my supervisor, Dr . Janice Eng, for her invaluable input and guidance over the last two years. Y o u are truly an inspiring researcher and role model of how to balance your academic and personal lives. I also need to thank the clinicians at G F Strong, especially Shannon and Ke l ly , for their interest and expertise in getting this study going, and for their help with subject recruitment. To my thesis committee; thanks to Dr. Andrei Krassioukov, for his dedication and commitment to the many hours of VO2 testing, to Dr. B i l l Mi l l e r for his statistical teaching and advice throughout this project, and to Dr. B i l l Sheel for acting as external examiner for my thesis defence. A big thanks to all the participants in this study. B y giving your time to this research, and some great efforts during the exercise tests, you made this project a success. To all the members of the Rehab Research Lab over the last 2 years: Jocelyn, Melanie, Marco, Lara, Karen, Chihya, Erica, Miho , Priscilla, Sarah, Amira, Dan, and Patrick. Y o u all made my time in the lab a fabulous experience, through your knowledge, your humour and your commitment to solid research. A couple of you deserve some special thanks: to Chihya, for all your help with testing and recruitment, and for always keeping the lab so cheerful, to Amira , for being such an accomplished lactate pricker and keeping my spirits up after months of data collection, and to Jocelyn, for your many hours of listening, advising, and picking up my spirits over countless coffee breaks at Children's. Finally, a big thank you to all my family and friends back home in Ontario. Your never ending support, despite not always understanding why I needed to move out west to do this masters was truly appreciated, and something that I w i l l never forget. ix Chapter 1: Introduction 1.1 Introduction Currently, there are approximately 36,000 Canadians l iving with a spinal cord injury (SCI). Each year in Canada, there are an estimated 1,050 new injuries that result in some level of permanent paralysis or neurological deficit (Canadian Paraplegia Association, 1997). The medical management of SCI has improved dramatically over the last 30 years, enabling individuals with SCI to have a life expectancy resembling that of the general population (DeVivo et al 1999; Krause et al. 2004). Accordingly, chronic diseases, specifically cardiovascular diseases, are now much more prevalent in individuals with SCI. The muscle paralysis associated with SCI imposes a more sedentary lifestyle, and it is suspected that this sedentary lifestyle contributes to the high prevalence of cardiovascular diseases in this population (Bauman et al. 1998; Bauman and Spungen 1994; Brenes et al. 1986; Dallmeijer et al. 1997; Dearwater et al. 1986; Demirel et al. 2001; Janssen et al. 1997). Today, SCI rehabilitation programs are increasingly intensive in their attempt to maximize cardiovascular fitness and include activities such as arm ergometry, functional electrical stimulation ergometer cycling, strength training and partial-body-weight supported treadmill training (Davis 1993; Kirshblum 2004). In order to determine an individual's level of cardiovascular fitness, some type of fitness assessment should be conducted. Maximal fitness tests are the most accurate type of fitness test (Taylor et al. 1955), but these require expensive equipment and medical personnel to 1 monitor the subject. Submaximal exercise tests are a safe and less expensive alternative to maximal tests, but most involve lower limb exercise (e.g. walking, cycling) and cannot be Completed by individuals with SCI. Although SCI rehabilitation programs include components that aim to increase cardiovascular fitness, clinicians are currently not able to quantitatively determine whether or not these interventions have been successful. A reliable and valid submaximal arm exercise test is clearly required. The first objective of this thesis was to investigate the evidence surrounding current submaximal arm exercise tests. Upon review o f the literature, a lack of evidence for these current tests warranted the development of a new submaximal arm exercise test. Accordingly, a new test was designed, and its reliability and criterion validity were measured. This process has been separated into two studies; the first examines the submaximal arm exercise tests that have previously been presented in the literature, and the second describes the new submaximal arm ergometer exercise test, with specific focus on its reliability and validity. The following section presents concepts and definitions o f selected physiological principles that are relevant to the studies presented in this thesis. Following this section, a brief literature review is included, and the theses purposes, research questions and hypotheses are presented. 2 1.2 Selected exercise physiology concepts The concepts and relationships that wi l l subsequently be described hold true for able-bodied individuals, and those with spinal cord lesions below T6. A s w i l l be discussed later in this chapter, spinal cord lesions above T6 can disrupt the sympathetic nerves innervating the heart, and drastically alter an individual's response to exercise. 1.2.1 Cardiovascular fitness, cardiac output and oxygen consumption A n individual's cardiovascular fitness reflects the maximal amount of oxygen consumed by their body during each minute o f near-maximal exercise. Values for peak oxygen consumption (VC^peak) are expressed in litres of oxygen used per minute (L/min), or more commonly, relative to body weight in millilitres of oxygen per kilogram body mass per minute (mL/kg/min). Individual values can range from 10 mL/kg/min in individuals with cardiovascular and respiratory diseases, to more than 80 mL/kg/min in elite runners and cross-country skiers (McArdle et al. 2001). VC^peak takes into account both an individual's maximal cardiac output, and the maximal amount of oxygen that can be extracted from the blood by their working muscles. Cardiac output is calculated as heart rate (HR) * stroke volume (the volume of blood ejected from the heart each beat). The health of the cardiovascular system, specifically the heart, can be measured by parameters other than VC^peak. Determining cardiac output, left ventricular end diastolic volume, and ejection fraction provides valuable information on the hearts contractility and 3 ability to pump sufficient blood through the body. Echocardiography uses sound waves directed at the chest wall to produce a moving picture o f the heart, and can be used to assess cardiac dimensions and function. Cardiac output can be determined non-invasively using foreign gas (carbon dioxide or acetylene) rebreathe techniques (McArdle et al. 2001). These different techniques are used both at rest and during maximal exercise and complement the information provided in a VG*2peak test to present a more comprehensive picture o f heart health and function. 1.2.2 Heart rate Heart rate is expressed as the number of heart beats per minute. Resting H R is dependent on physical fitness, with fitter individuals having a lower resting H R . The resting H R o f a young infant is higher than an adult, but in adults, resting H R is not age dependent. Maximal H R is age related over the entire lifespan (Hagberg et al. 1985); with increasing age, maximal H R declines, and in able-bodied populations, can be approximated by the equation: maximal H R = 220-age . 1.2.3 Power output During cardiovascular exercise, individuals continuously exert forces either through their arms (e.g. during arm ergometry) or their legs (e.g. during treadmill running or leg cycling). The application of these forces relative to time is expressed as an individual's power output 4 (PO) (Robergs and Roberts 1997), and is typically measured in Watts (W). PO can be thought of as the intensity of the exercise. 1.2.4 Oxygen consumption-power relationship The relationship between oxygen consumption (VO2) and P O is generally linear, with increased workloads requiring an increase in oxygen consumption. During incremental exercise, VO2 increases in a manner that is dependent on the rate o f increase in PO. Figure 1.1 presents the change in VO2 during two different protocols (dashed line - ramp protocol; solid line - 50 W increments every 3 minutes) for the same individual. The ramp protocol shows a linear increase in VO2 with PO, and a plateau in VO2 at V02peak, while the step protocol reveals a "staircase" effect of increasing VO2. During the three minute stages in the early part of step protocol, the VO2 is able to reach steady state. Later in the test however, the relative intensity increment and absolute intensity are too great for steady state to be achieved, and the increase in VO2 appears more linear until V02peak is attained (Robergs and Roberts 1997). In individuals with SCI, the linear increase in V 0 2 with P O remains, but the slope of this line changes with lesion level. The slope o f this line is steeper for able-bodied individuals than for those with paraplegia, who in turn have a steeper slope than those with tetraplegia (Schmid et al. 1998). During submaximal exercise at a constant PO, VO2 initially increases exponentially, and then reaches a steady state (Figure 1.2). 5 1.2.5 Oxygen consumption — heart rate relationship There is a general linear relationship between H R and VO2. Figure 1.3 illustrates this relationship in two individuals of different fitness levels. Both individuals are undergoing a VChpeak test, and it can be seen that for both individuals, H R increases proportionately with 3.0 0.0 H : 1 : F 1 r- , 1 \ 0 2 4 6 8 10 12 14 (rest) Time (min) Figure 1.1 Relationship between VO2 and PO: Linear increase with a ramp protocol (dashed line), "staircase" effect seen when P O increases in three minute stages (solid line) (adapted from Robergs and Roberts 1997) 0 A : , , , : , 1— 0 2 4 6 8 10 ( r 6 S t ) Time (min) Figure 1.2 Change in V 0 2 during the transition from rest to submaximal exercise at a constant P O (adapted from Robergs and Roberts 1997) 6 VO2. Although both individuals show a linear relationship, the same H R corresponds to different VO2 values in each subject. The slope of this line is different for everyone, with a steeper slope generally indicating a less fit individual. When exercising at a given VO2, approximately the same cardiac output is required to supply the oxygenated blood to the working muscles, regardless of fitness level. Generally, individuals with increased fitness have a higher stroke volume, so a lower H R is required to obtain the needed cardiac output. This higher stroke volume coupled with the unchanged maximum H R translates into increased cardiovascular fitness. 200 0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 V02(L/min) Figure 1.3 Linear relationship between H R and VO2 for two individuals with different cardiovascular fitness levels (adapted from McArd le et al. 2001) 1.2.6 Heart rate-power output relationship Similar to the relationship between H R and VO2, H R increases approximately linearly with increases in PO. This relationship is also influenced by cardiovascular fitness level, with 7 fitter individuals having a lower H R for a given PO. Figure 1.4 illustrates the H R - P O relationship from two individuals during a V02peak test. The line with the steeper slope belongs to the less fit individual. A similar trend is seen individuals with SCI; those with paraplegia (who are often more physically fit) tend to have a steeper slope than those with tetraplegia (Schmid et al. 1998). 200 - i — — , 40 -I 1 , , : , 1 0 50 100 150 200 250 Power output (W) Figure 1.4 Linear relationship between H R and P O for two individuals with different cardiovascular fitness levels (adapted from McArdle et al. 2001) During submaximal exercise at a constant PO, H R initially increases exponentially, then plateaus to a steady state. Figure 1.5 illustrates the responses o f two different individuals to steady state submaximal exercise at the same PO. The light line at the higher steady state H R represents a less fit individual. Recall that P O and VO2 are linearly related, so for these individuals working at the same PO, the same amount of oxygen is required by the working 8 muscles, and thus their cardiac output needs are the same. As outlined previously, the individual with a higher fitness level has an increased stroke volume, so a lower H R is required to produce the cardiac output needed to deliver sufficient oxygenated blood to the working muscles. 140 0 H , 1 1 , -• 1 0 1 2 3 4 5 6 Time (min) Figure 1.5 H R response to six minutes of submaximal steady state exercise at the same constant PO for two individuals with different cardiovascular fitness levels 1.2.7 Blood lactate Lactate is produced in active muscles during carbohydrate metabolism. A t rest and during low intensity exercise, lactate is used by the muscle at the same rate that it is produced and blood lactate levels remain low and constant (~1 mmol/L at rest and < 4 mmol/L during steady state exercise) (Robergs and Roberts 1997). During more intense exercise, lactate is produced faster than it is used by the working muscle and it accumulates in the blood. Increased lactate decreases blood p H , and results in a condition of lactic acidosis. The acidic 9 environment that results with the increase in lactate is partially responsible for the fatigue and pain of the exercising muscle (Robergs and Roberts 1997). In healthy individuals, lactate levels can increase up to 14-16 mmol/L during intense exercise (Robergs and Roberts 1997), but in individuals with SCI, even maximal exercise only produces lactate levels o f 9-10 mmol/L (Flandrois et al. 1986). 1.3 Pathophysiology of SCI 1.3.1 SCI and motor system dysfunction Interruption o f the spinal cord results in impairment within the motor system. Depending on the anatomical location of the lesion within the spinal cord, an individual w i l l have partial or full paralysis of their upper and/or lower limb muscles. Lesions in the lumbar or thoracic regions of the spinal cord typically result in paraplegia with impairment to the lower limb and trunk muscles. Cervical lesions result in tetraplegia, with lower limb, trunk and upper limb muscle impairment. In addition to the muscle paralysis, the absence of functional muscle mass in the lower extremity limits the capacity of the cardiovascular system by eliminating the skeletal muscle pump that aids in returning blood to the heart (Hopman et al. 1993). 10 1.3.2 SCI and sympathetic nervous system dysfunction A s well as the motor system limitations, many individuals with SCI, especially those with higher lever lesions, have diminished sympathetic output from the sympathetic nervous system (Wecht et al. 2001). Without adequate sympathetic stimulation, a number o f autonomic and cardiovascular complications arise. Complications that have important implications during exercise are hypotension (Dela et al. 2003), bradycardia (Wecht et al. 2001), and impaired thermoregulation (Price and Campbell 1999). 1.3.3 Exercise implications A r m exercise uses smaller and weaker muscles relative to leg exercise. Using these smaller muscles immediately limits the maximal PO, and thus the V02peak that can be attained during arm exercise. A s well , without the leg muscle pump actively working to return blood to the heart during exercise, blood pools in the legs and decreases blood pressure (BP). Without adequate stimulation from the sympathetic nervous system, normal cardiovascular responses to exercise such as vasoconstriction in less active tissue (e.g. kidneys, gastrointestinal tract), vasodilation in skeletal muscle, increases in H R , and increases in stroke volume are impaired. The sympathetic nerves that innervate the heart are located from T I to T7 (Barron and Blair 1999), so individuals with lesions above T I have a very limited ability to increase their H R , stroke volume, heart contractility and cardiac output 11 (Freyschuss and Knutsson 1969). For individuals with intact sympathetic stimulation of the heart, the increase in H R at the start of and during lower intensity exercise is primarily due to inhibitory parasympathetic stimulation sent through the vagus nerves. During higher intensity exercise, the further increases in H R are due to a combination of additional parasympathetic inhibition and activation of the sympathetic nerves to the heart (Nobrega and Araujo 1993). In individuals with complete tetraplegia, the sympathetic innervation to the heart is still intact, but signals that originated in the central nervous system cannot be transmitted to the sympathetic nerves because of the injury within the spinal cord. In these individuals, the H R increase in response to exercise is due to the withdrawal o f vagal parasympathetic tone, and as a result, maximal exercising H R rarely exceeds 100-125 beats/minute (Davis 1993). Without the ability to substantially increase cardiac output, an individuals' capacity for exercise is severely limited. Clearly, testing cardiovascular fitness in individuals with SCI requires special considerations. The following chapters 1) present a thorough literature review on submaximal exercise tests that have been designed for use in individuals with SCI, and 2) propose a new submaximal arm ergometer exercise test, with specific focus on its reliability and validity. 12 1.4 Purpose The purpose of this study was twofold: 1) to systematically review current literature that investigates submaximal cardiovascular exercise testing in individuals with SCI, and 2) to design a submaximal single-stage arm ergometer test (SSSAET) for use i n individuals with SCI arid to determine its test-retest reliability and criterion validity. 1.5 Research questions and hypotheses 1.5.1 Research question 1: Have any submaximal exercise tests that can be used clinically to estimate cardiovascular fitness in individuals with SCI been presented in the literature? Hypothesis: Submaximal exercise tests that can be used clinically to estimate cardiovascular fitness in individuals with SCI are lacking. 1.5.2 Research question 2: Is the S S S A E T reliable when performed on two separate occasions, and is it a valid measure of cardiovascular fitness for individuals with SCI? Hypothesis 1: The steady state H R and VO2 responses during the S S S A E T w i l l be reliable when measured on two separate occasions. Hypothesis 2: Power output and steady state VO2 and H R during the S S S A E T w i l l correlate with VC»2peak. 13 Chapter 2: A systematic review of submaximal exercise tests for individuals with spinal cord injury 2.1 Abstract Background and Purpose: Submaximal exercise tests can be useful clinical tools to assess cardiovascular Fitness, but the availability o f these tests for use i n individuals with spinal cord injury (SCI) has not been presented. The purpose o f this study was to review current literature and develop guidelines to assist clinicians in choosing appropriate submaximal tests for the evaluation of cardiovascular fitness in individuals with SCI. Methods: A systematic review o f the literature was performed to identify and evaluate arm exercise tests that submaximally measure cardiovascular fitness in individuals with SCI. Tests were categorized as predictive or performance tests and evaluated for reliability, validity and responsiveness. Results: Six submaximal exercise tests for measuring cardiovascular fitness in individuals with SCI were identified. Two additional articles were included in this review as they described aerobic training interventions in individuals with SCI and assessed the change in cardiovascular fitness using submaximal exercise tests. The total number o f subjects included in the studies was 210. Two predictive tests and 4 performance based tests were identified. Only 2 tests reported reliability and responsiveness (all reported values were acceptable), while 5 tests reported validity values (1 was fair, 2 moderate, and 2 excellent). Conclusions: Clinical recommendations were made, but given the limitations with each of the 6 tests, further research is required to develop and evaluate a submaximal exercise test for individuals with SCI that has strong psychometric properties. 14 2.2 Introduction The medical management of acute and chronic SCI has improved dramatically in the last thirty years, enabling individuals with SCI to have a life expectancy resembling that of the general population (Devivo et al. 1999; Krause et al. 2004). Accompanying this longer survival are chronic diseases such as diabetes and cardiovascular disease that were previously uncommon in those with SCI (McGlinchey-Berroth et al. 1995). Over the last thirty years, there has been a shift in the predominant cause o f death in individuals with SCI from genitourinary infections to respiratory and cardiovascular diseases (DeVivo et al. 1993; Frankel et al. 1998; Soden et al. 2000). A number of risk factors for both able-bodied populations and individuals with SCI are indicative of a high risk of developing coronary artery disease ( C A D ) . The American College of Sports Medicine ( A C S M ) (2000) lists hypertension, high cholesterol, impaired fasting glucose, obesity, family history and a sedentary lifestyle as measurable risk factors that have clinically relevant thresholds for describing an individual's level of risk for C A D . Many of these risk factors are highly associated. For instance, by increasing an individuals level o f physical activity, not only have they decreased their risk for C A D by moving away from a sedentary lifestyle, but additional positive effects including reduced hypertension, improved fasting glucose levels, increased high density lipoprotein cholesterol levels, and decreased body weight may occur ( A C S M 2000). The cross over effects between risk factors makes it difficult to study a single risk factor independently. 15 Hypertension is one o f the risk factors for C A D , so the hypotension that often accompanies a SCI (Noreau et al. 2000) complicates the assessment o f C A D risk. The absence of functional muscle mass in the lower extremity eliminates the skeletal muscle pump, resulting in venous pooling. A s blood pools in the lower extremities, venous return to the heart is reduced, and cardiac output decreases. This venous pooling is compounded by the lack of sympathetically driven vasoconstriction (Hopman et al. 1993), and can result in severely decreased blood pressure during arm exercise. When looked at independently, this hypotensive state appears to represent a decreased risk for C A D , but epidemiological studies clearly show that individuals with SCI have a risk at least as high, i f not higher than the general population (Bauman et al. 1992; DeVivo et al. 1993; Yekutiel et al. 1989), and that this risk cannot be offset by the hypotension accompanying a SCI. In addition to general hypotension, over 50% of individuals with SCI experience orthostatic intolerance (Cariga et al. 2002), and nearly all individuals with SCI experience exertional hypotension (King et al. 1994). Orthostatic hypotension is characterized by a sudden drop in blood pressure when moving from a lying position to a sitting or standing position (McArdle et al. 2001), while exertional hypotension is seen as decreasing blood pressure as exercise progresses (Glaser et al. 1980). Orthostatic hypotension is more prevalent in those with higher level injuries (Cariga et al. 2002). There are two risk factors that appear to be most associated with increased C A D risk for individuals with SCI. The first is their relatively low level of physical activity. Exercise capacity is limited in these individuals in part because of the impaired cardiovascular responses to exercise (following the SCI and resultant impairment of the sympathetic nervous 16 system), and the limited available functional muscle mass. In addition to a now pathologically limited exercise capacity, many individuals with SCI also lead a very sedentary lifestyle (Buchholz et al. 2003; Hoffman 1986; Monroe et al. 1998). I f lifestyle modifications are made to improve physical fitness, studies of individuals with SCI have shown that not only is C A D risk decreased (Brenes et al. 1986; Dearwater et al. 1986), but individuals also experience decreased strain during activities of daily living (Janssen et al. 1996). The second is the high prevalence of metabolic syndrome within this population. Metabolic syndrome is characterized by a group of metabolic symptoms including abdominal obesity, elevated low density lipoprotein cholesterol and triglycerides, low levels of high density lipoprotein cholesterol, and insulin resistance (Reaven 2002). A combination of these symptoms, most often glucose intolerance and elevated low density lipoprotein concentration, has been observed in up to 50% of individuals with SCI (Zhong et al. 1995). Individuals with metabolic syndrome have been shown to be at increased risk for C A D (McNei l l et al. 2005). Studies of individuals with SCI have shown physical activity level (Dallmeijer et al. 1997) and body composition (Janssen et al. 1997) to be associated with lipoprotein levels. A recent study by Manns et al. (2005) found that in individuals with SCI, lower physical activity levels were associated with higher fasting glucose, lower high density lipoprotein concentrations and greater waist circumference measurements. The measurement of cardiovascular fitness is important in all populations as it can provide an estimate of C A D risk. Measuring cardiovascular fitness is especially important for individuals with SCI, given the high incidence of C A D in this population. Cardiovascular fitness testing can also provide an evaluation of some medical abnormalities, motivate 17 individuals by helping to establish attainable fitness goals, and be used as a baseline measure for exercise prescription ( A C S M 2000). The gold standard test for measuring cardiovascular fitness is the peak oxygen consumption (VChpeak) test (Taylor et al. 1955). This type o f test requires expensive equipment to analyze the respiratory gases and trained personnel to operate the equipment and conduct the tests. In individuals with SCI, impairments to the nervous system change the physiological responses to exercise, and the stresses that are placed upon the cardiovascular and respiratory systems during these maximal tests may place certain individuals at risk. Accordingly, submaximal exercise tests that do not require respiratory gas analysis have been designed to evaluate cardiovascular fitness. Clinicians typically choose to assess cardiovascular fitness using submaximal tests, but the availability o f these tests for use in individuals with SCI has not been presented. The purpose of this paper was to systematically review current literature and develop guidelines to assist clinicians in choosing appropriate submaximal tests for the evaluation of cardiovascular fitness in individuals with SCI. 2.3 Methods Articles were included in this review i f they were (1) research studies using submaximal cardiovascular fitness tests for use for individuals with SCI and (2) studies found in the M E D L I N E , Cumulative Index to Nursing and Allied Health Literature ( C I N A H L ) , or Excerpta Medica ( E M B A S E ) databases, or in the reference lists of articles found in these databases. 18 2.3.1 Search strategy A systematic review of the literature was conducted through the local university's online library system using M E D L I N E (1966 to July week 2,2005), C I N A H L (1982 to July week 3, 2005) and E M B A S E (1980 to week 30, 2005). The search strategy for the M E D L I N E search is presented in Appendix A . A n equivalent search strategy was used for the C I N A H L and E M B A S E databases with minor modifications due to differences in indexing and syntax in the different databases. Using this search strategy, 117, 75, and 98 articles were found in M E D L I N E , C I N A H L , and E M B A S E , respectively. A total o f 201 unique articles were identified using these search strategies. The titles, abstracts, and i n some cases the entire article, were reviewed, and those not related to the topic o f study were excluded. The articles remaining following the initial screening were then reviewed for additional references. After eliminating 193 articles that did not meet all the inclusion and exclusion criteria, the submaximal cardiovascular fitness tests that were described in the articles were categorized as either predictive or performance based tests. Typically, predictive tests measure an individual's heart rate (HR) while exercising at one or more submaximal power outputs (PO), then extrapolate from the linear relationship between H R and VO2 to the age predicted maximal H R where an estimate of V02peak can be made. Performance tests measure an individual's response to standardized physical activities, such as the time to cover a certain distance or the maximum distance an individual can walk/run in a given amount of time (Noonan and Dean 2000). The time (or distance) can be used as the sole outcome 19 measure for the test, but often the time (or distance) is entered into an equation to predict V0 2 peak. A description of each df the submaximal cardiovascular fitness tests, as well as the psychometric properties of the each test was extracted from the articles and is reported in Table 2.1 (at the conclusion o f this chapter). The following criteria was used for evaluating correlation coefficients: 0.0-0.25 poor, 0.25-0.50 fair, 0.50-0.75 moderate to good, 0.75-1.0 good to excellent (Portney and Watkins 2000). 2.4 Results A total of 6 articles were identified that describe submaximal cardiovascular fitness tests for individuals with SCI (Dwyer and Davis 1997; Franklin et al. 1990; Kofsky et al. 1983; Longmuir and Shephard 1993; 1995; Rhodes et al. 1981). Two additional articles have been included, as they use aerobic training interventions for individuals with SCI (DiCarlo 1988; Hicks et al. 2003) and assess the change in cardiovascular fitness using submaximal exercise tests. In the 8 studies included in this review, sample size ranged from 8 to 49 subjects, with a total of 210 different individuals with SCI participating. 2.4.1 Predictive tests There have been two submaximal predictive tests developed for estimating VG^peak in individuals with SCI (Table 2.1). The test designed by Kofsky et al. (1983) involved having 20 49 subjects cycle at 3 submaximal PO ' s on an arm ergometer while VO2 was measured. O f the 49 subjects, there were 8 individuals with tetraplegia, 34 with paraplegia and 7 with unspecified lower limb disabilities. For individuals with tetraplegia, the correlation between P O and measured VO2 was poor (r=0.12), so these subjects were excluded from further analyses. For the remaining subjects, the correlations of P O with measured VO2 were excellent (females r=0.85, males r=0.88), and allowed simple regression equations to be developed to predict VO2 while arm cycling at submaximal POs. These submaximal VO2 values were then used with the modified Astrand-Ryhming nomogram (Astrand 1960; Shephard 1972) to predict V0 2 peak. The Astrand-Ryhming nomogram is reliable and valid (Macsween 2001), and uses an individual's FIR response to cycling at a specific submaximal P O along with age and gender to predict V0 2peak. Kofsky et al. (1983) found the correlations between predicted V0 2 peak and measured V02peak to be moderate (males r=0.67, females r=0.61). In a randomized controlled trial o f exercise training in individuals with SCI, Hicks et al. (2003) used the protocol presented by Kofsky et al. (1983) to assess submaximal arm ergometry performance. Sixteen subjects with paraplegia arm cycled at 3 submaximal PO ' s approximating 40%, 60% and 80% of age-predicted maximal H R , while 18 subjects with tetraplegia arm cycled at intensities that elicited Borg ratings of perceived exertion (RPE) of 1 (very weak), 2 (weak) and 4 (somewhat strong) from Borg's 10-point R P E scale (Borg 1982). Following a 9-month resistance and aerobic training program, PO during the third submaximal stage increased by 82% for subjects in the intervention group (118% increase for subjects with tetraplegia, 45% increase for subjects with paraplegia), while no change was 21 observed in the control group. Although the predictive equations developed by Kofsky et al. (1983) were not used in this study, their test protocol was followed, and the submaximal P C s were found to be responsive to those that did and did not undergo exercise training. The second predictive test is a modified version of the Canadian Aerobic Fitness Test ( C A F T ) (Longmuir and Shephard 1993; 1995). In this study, 46 individuals with a variety o f orthopaedic and neuromuscular impairments, including 9 subjects with SCI, completed up to three submaximal exercise stages on an arm ergometer. The P O of each stage increased by increasing cranking cadence according to age and gender-specific test stages provided by the C A F T . H R was taken at the end of each stage, and i f it exceeded a predetermined ceiling count, the test was terminated. Age, body mass, H R during the final testing stage, and oxygen cost o f the final testing stage (taken from a table) were entered into the predictive equation from the Canadian Standardized Test of Fitness (CSTF) to estimate V02peak. This submaximal test was repeated after approximately one week. The reliability of the predicted V02peak over this week was excellent (ICC=0.97), but the correlation between predicted V02peak and measured V02peak was only fair (r=0.51). Also, although 87% of healthy, able-bodied adults were able to complete the modified C A F T (Longmuir and Shephard 1993), only 35% o f subjects with mobility impairments were able to maintain the appropriate arm cycling cadence to complete the test (Longmuir and Shephard 1995). 22 2.4.2 Performance based tests Four performance based submaximal exercise tests for individuals with SCI have been presented in the literature (DiCarlo 1988; Dwyer and Davis 1997; Franklin et al. 1990; Rhodes et al. 1981). Each of these tests involves a continuous wheeling task for 12 minutes, with the primary outcome measure being the distance wheeled during that time (Table 2.1). The distance wheeled during 12 minutes of continuous wheeling around a 200 metre track was used by DiCarlo (1988) to measure functional endurance in 8 subjects with tetraplegia. The validity o f this test was not determined, but test-retest reliability over separate days was excellent, with an ICC of 0.97 between days. Following a cardiovascular training program done by the same 8 men, DiCarlo (1988) found wheeling distance to increase proportionately to VChpeak, indicating the tests ability to detect change. Both Franklin et al. (1990) and Rhodes et al. (1981) found the distance wheeled in 12 minutes to have moderate to good correlations with VChpeak (r=0.50 to r=0.84), and used these distances to develop predictive equations for VG^peak. Using 30 male subjects (25 with paraplegia, 2 with post-polio syndrome and 3 with lower limb amputation), Franklin et al. (1990) found the distance wheeled to accurately predict VChpeak (standard error of estimate (SEE)=0.13). Rhodes et al. (1981) tested 30 male subjects with SCI (10 with tetraplegia, 20 with paraplegia) and found the correlations between measured VChpeak and predicted VG^peak to range from r=0.69 to r=0.88, depending on lesion level. Both of these studies only used male subjects, so Dwyer and Davis (1997) suggested that the study should be repeated with female subjects to increase the generalizability o f these findings. They did not, however, find the 12 minute wheeling distance to be correlated to VChpeak. A l l subjects in the DiCarlo (1988) and 23 Rhodes et al. (1981) studies had a SCI, but in the study by Franklin et al. (1990), although all subjects were manual wheelchair users, not all subjects had a SCI; those with post-polio and lower limb amputations were also included. The diagnosis of subjects is not included in the Dwyer and Davis (1997) study; it is only stated that all subjects had a lower limb disability. O f the studies included in this review, only one adverse effect was reported. The wheelchair of one subject in the Franklin et al. (1990) study overturned while he was completing the 12 minute wheeling test, but no serious abrasions or musculoskeletal complications occurred. A s none of the studies reported the blood pressure (BP) responses to either the submaximal tests or the validating V02peak tests, it is unknown i f any subjects experienced exertional hypotension. 2.5 Discussion Submaximal exercise tests have several advantages over maximal exercise tests. Physician supervision is not generally required when conducting these tests, because individuals are not attempting to maximize their cardiovascular systems. The exertional hypotension that often accompanies exercise in individuals with SCI has been found to be more frequent and more severe during maximal exercise compared to submaximal exercise (Drory et al. 1990; K ing et al. 1994). Consequently, during submaximal exercise individuals are at less risk for the lightheadedness and dizziness that can accompany exertional hypotension. Gas analysis equipment is not required to conduct submaximal field tests, so 24 clinicians do not require extensive training to operate the equipment. A s well , less time is typically required to run a submaximal exercise test compared to a maximal test. The field tests described by DiCarlo (1988), Dwyer and Davis (1997), Franklin et al. (1990) and Rhodes et al. (1981) require minimal equipment, and are inexpensive to administer. Rhodes et al. (1981) found the 12 minute wheeling distance better at predicting V0 2 peak in individuals with tetraplegia compared to those with paraplegia, and DiCarlo (1988) found a similar wheeling task to be reliable and responsive to an increase in VChpeak in individuals with tetraplegia. The wheeling tests demonstrated, at best, moderate validity in individuals with paraplegia. These tests have only been validated only on 200 and 400 metre tracks, and access to these facilities is rarely available clinically. If a shorter wheeling circuit were used, the wheeler would spend much of their time cornering, and not actively pushing, therefore they would not be able to attain a sufficiently high intensity of wheeling to measure cardiovascular fitness. Additional concerns for this type of exercise test include having a standardized surface for the wheeling to take place on, and use of standard versus lightweight wheelchairs. Wheeling over surfaces with higher levels of friction (gravel or rubberized track versus pavement) and using heavier chairs would likely result in shorter distances wheeled, and an underestimation o f cardiovascular fitness. Dwyer and Davis (1997) did not find the distance wheeled to be correlated to VC»2peak, but all o f their subjects were female wheelchair basketball players with paraplegia or other lower limb disabilities. Although their VChpeak values ranged from 15.7 to 36.2 mL/kg/min the range of the distance wheeled was much less varied (1950-2350 m). As all subjects were physically active, their similar wheeling distances may demonstrate a ceiling effect of this test. 25 The tests described by Kofsky et al. (1983) and Longmuir and Shephard (1993; 1995) use an arm ergometer and H R monitor, equipment which is l ikely available in most rehabilitation settings. The practicality of the modified C A F T is limited. Although 87% of healthy, able-bodied subjects were able to complete the modified C A F T (Longmuir and Shephard 1993) only 33% of subjects with mobility impairments (including those with SCI) were able to arm cycle at the required cadences to complete the test (Longmuir and Shephard 1995). Thus, this test is inappropriate for the majority of its intended population. Most predictive submaximal exercise tests, including the test presented by Kofsky et al. (1983), use an individual's H R response to one or more submaximal PO ' s to predict an individual's V0 2 peak . These predictions are based on the assumption that H R and VO2 have a linear relationship throughout the range of PO ' s up to that individual's maximum. It is important to note several issues regarding this assumption. First, H R can vary independently of VO2 due to a number of factors including hydration status, caffeine intake, haemoglobin levels and emotional state (Rowell et al. 1964). Secondly, in able-bodied individuals, maximal H R is attained at a work rate slightly under VChpeak, and consequently most predictive equations underestimate VChpeak (Macsween 2001). Third, predictive tests require the estimation o f maximal H R . In able-bodied individuals, age-predicted maximal H R is typically estimated using the equation '220-age' ( A C S M 2000), but this has been found to vary five percent with age (Wyndham 1967). This means that V0 2 peak is likely to be over or under-estimated for each individual. Although this standard maximal H R equation appears to be valid for individuals with a low paraplegic level SCI (Pare et al. 1993), interruptions to the nervous system at and above T6 alter the H R response to exercise. A s 26 previously discussed, individuals with lesions to the sympathetic nerves higher than T6 have a limited ability to increase their H R and their maximal H R rarely exceeds 100-125 beats/minute. A s a result, the traditional predictive equations that rely solely on an individuals H R response to exercise are not appropriate for individuals with a high level SCI. The test presented b y Kofsky et al. (1983) used the modified Astrand-Ryhming nomogram (Astrand 1960; Shephard 1972) to predict VChpeak, which is based upon the linear HR-VO2 response to exercise. Although the data from subjects with tetraplegia was not used in the development of the predictive equation, individuals with high level (above T6) paraplegia were included, and their impaired H R response to exercise may in part explain why only moderate correlations between predicted and measured VG^peak were found. Similarly, the arm C A F T described by Longmuir and Shephard (1993; 1995) used subjects H R following their final submaximal stage in the prediction equation for VC>2peak. Although some of the submaximal exercise tests presented in this review have been reported as reliable and/or valid, none are commonly used to evaluate fitness in the intended population, and most have only been validated in a small subset of individuals with SCI, such as athletes, males, or those with paraplegia. For an exercise test to become a useful outcome measure in a rehabilitation or fitness program, it must be reliable, valid and responsive to change (Streiner and Norman 1995). O f the 6 tests previously discussed (Table 2.1), 2, 5 and 2 described reliability, validity and responsiveness, respectively. Although researchers began describing the measurement 27 properties of each of these exercise tests, no single test was reported to be reliable, valid and responsive to change. 2.5.1 Recommendations O f the current tests that have been described, it is recommended that the wheeling test presented by Rhodes et al. (1981) be used to assess cardiovascular fitness in individuals with tetraplegia, while the submaximal test presented by Kofsky et al. (1983) be used for individuals with paraplegia. The wheeling tests (DiCarlo 1988; Dwyer and Davis 1997; Franklin et al. 1990; Rhodes et al. 1981) all have slight methodological differences, but the psychometric properties of each are low in subjects with paraplegia and higher in those with tetraplegia. The main limitation to administering this test is the availability of a large indoor or outdoor track. I f a track is not available, the Kofsky et al. (1983) protocol, or a modification of it (Hicks et al. 2003) is a feasible alternative for assessing cardiovascular fitness in individuals with SCI. Hicks et al. (2003) demonstrated that a variation of the Kofsky et al. (1983) protocol is sensitive to change in both individuals with tetraplegia and paraplegia. This fact, along with its stronger validity values in individuals with paraplegia, makes it more appropriate than the wheeling tests for the evaluation of cardiovascular fitness in individuals with paraplegia. Current tests do exist that can be used to assess cardiovascular fitness in individuals with SCI, but the need remains for a submaximal arm exercise test that has defined measurement properties. With a valid, reliable and responsive assessment tool, therapists w i l l be better able 28 to educate and provide feedback about cardiovascular fitness to their clients as they progress through a rehabilitation or training program. This information may help to motivate individuals with SCI to increase their physical activity level, and therefore help to decrease their risk for C A D . 2.6 Summary From the submaximal exercise tests presented in the literature, the following recommendations can be made for the assessment of cardiovascular fitness in individuals with SCI: • For individuals with tetraplegia: If a track is available, the equations developed by Rhodes et al. (1981) should be used. If no track is available, the Kofsky et al. (1983) protocol should be followed. • For individuals with paraplegia: The Kofsky et al. (1983) protocol should be followed. There are limitations to each of these tests, however, and further research is required to develop and evaluate a submaximal exercise test for individuals with SCI that has strong psychometric properties. 29 Table 2.1 Submaximal exercise tests Author Subjects Protocol of Test(s) Results/Primary Findings DiCarlo 1988 8 subjects with tetraplegia; male; mean age 23.6 years; lesion level C5-C7 SUBMAXIMAL PERFORMANCE TEST Sustained wheelchair propulsion for 12 minutes around a 200 metre indoor track. Total distance covered was measured. This test was repeated 3 times on alternate days. • Pearson product-moment correlation of r=0.97 between trials. Following cardiovascular training, propulsion distance increased proportionally to an increase iri VQ 2 peak. Dwyer and Davis 1997 13 subjects (with paraplegia or other lower limb disability); female; mean age 26 years SUBMAXIMAL PERFORMANCE TEST Continuous wheeling to "cover the greatest possible distance" in 12 minutes around a 200 metre indoor track. Total distance covered was measured. A r m ergometer V02peak test also completed. Correlation between distance wheeled and V0 2 peak (L/min): r=0.30 (p>0.05) Franklin et al. 1990 30 subjects (25 with paraplegia, 2 post-polio patients, 3 with lower limb amputation); male; mean age 34.3 years SUBMAXIMAL PERFORMANCE TEST Continuous wheeling to "cover the greatest possible distance" in 12 minutes around a 0.1 mile indoor track. Total distance covered was measured. A r m ergometer V0 2 peak test also completed. Results from submaximal test used to develop predictive equation for VQ2peak. Correlation between distance wheeled and V0 2 peak (L/min): r=0.84 (pO.OOl) Regression equation developed: V02peak (mL/kg/min) = [distance wheeled (miles) - 0.370] 0.0337 SEE=0.13 Author Subjects Kofsky et al. 49 subjects with 1983 lower limb disabilities; 42 male, 7 female; mean age 28.3 years; 8 with tetraplegia, 34 with paraplegia, 7 with unspecified lower limb disabilities lesion Protocol ofTest(s) SUBMAXIMAL PREDICTIVE TEST Subjects performed 3 submaximal bouts on the arm crank ergometer, eliciting H R ' s of approximately 40, 60 & 80% of age-predicted maximum. A r m ergometer VChpeak test also completed. Results from the submaximal stages of the V0 2 peak test were used to develop predictive equations for submaximal VO2. Predicted submaximal VO2 values were used along with the modified Astrand-Ryhming nomogram to predict V02peak. Results/Primary Findings Regression equations developed from V0 2 peak tests to predict V 0 2 at submaximal P O ' s (excluding those with tetraplegia): For males: V 0 2 (L/min) = 0.018 [PO (Watts(W))] + 0.40 For females: V 0 2 (L/min) = 0.017 [PO (W)] + 0.37 Correlation between predicted V 0 2 p e a k value and measured V0 2 peak : For males, r=0.67, for females r=0.61, but large standard deviations for individual submaximal predictions Hicks et al. 2003 34 subjects with SCI; male and female (unspecified numbers); mean age 39.3 years; 18 with tetraplegia, 16 with paraplegia Randomized controlled trial of 9 month resistance and aerobic training program, To assess submaximal arm ergometry performance, subjects performed 3 submaximal bouts on the arm crank ergometer, eliciting either H R ' s of approximately 40, 60 & 80% of age-predicted maximum (subjects with paraplegia) (from Kofsky et al. 1983) or Borg ratings of perceived exertion of 1 (very weak), 2 (weak) and 4 (somewhat strong) from Borg's 10-point scale (subjects with tetraplegia). Following the training program, PO during the third submaximal stage increased by 82% for subjects in the intervention group (118% increase for subjects with tetraplegia, 45% increase for subjects with paraplegia), while no change was observed in the control group. Author Subjects Longmuir and 46 subjects with Shephard 1993; various 1995 orthopaedic and neuromuscular impairments including 9 subjects with SCI; 22 male, 24 female; mean age 40 years Protocol of Test(s) SUBMAXIMAL PREDICTIVE TEST Subjects performed 3 submaximal bouts of exercise at a low resistance on an arm ergometer. Cadence increased with each stage according to age and gender specific test stages (following the protocol of C A F T ) . V0 2 peak was predicted using a modified C S T F equation: V0 2 peak (mL/kg/min) = 42.5 + 16.6*oxygen cost of given test stage (L/min) -0.12*body mass (kg) -0 . 1 2 * H R - 0.24*age (years) Results/Primary Findings Practicality: Appropriate arm cranking rhythms could only be maintained by 35% of subjects Reliability of predicted V0 2 peak: ICC=0.97 . Correlation between measured V 0 2 p e a k and predicted V0 2 peak: r=0.51 This test was repeated after one week. A r m ergometer V0 2 peak test also completed. Protocol ofTest(s) SUBMAXIMAL PERFORMANCE TEST Continuous wheeling around a 400 metre track for 12 minutes. Total distance covered was measured. Author Subjects Rhodes et al. 30 subjects with 1981 SCI; male; mean age 31.0 years; 10 with tetraplegia, 20 with paraplegia Wheelchair ergometer V02peak test also completed. Results from submaximal test were used to develop predictive equations for V02peak. Results/Primary Findings Correlation o f distance wheeled and V0 2 peak: For all subjects r=0.80 For subjects with paraplegia r-0.54 For subjects with tetraplegia r=0.50 Three regression equations were developed: For all subjects: V 0 2 p e a k (L/min) = 0.984 distance (km) + 0.011 systolic B P (resting) - 0.009 diastolic B P (resting) + 0.007 weight (kg)-1.051 r=0.85, SEE=0.38 L/min For those With Paraplegia: VO^peak (L/min) = 0.3 distance + 0.007 systolic B P - 0.022 diastolic B P - 0.11 age (closest year) + 0.013 height (cm) + 0.36 r=0.69, SEE=0.32 L/min For those with Tetraplegia: V02peak (L/min) = 0.003 diastolic B P - 0.122 distance - 0.008 age + 0.01 weight - 0.12 height + 2.652 r=0.88, SEE=0.16 L /min V Chapter 3: Reliability and validity of a submaximal arm ergometer test for the evaluation of cardiovascular fitness in individuals with spinal cord injury 3.1 Abstract Background and Purpose: The prevalence of cardiovascular disease in individuals with spinal cord injury (SCI) is as high as or greater than in the general population. Despite the arm exercise tests that have been proposed, the need remains for a submaximal exercise test that is inexpensive, simple to administer in clinics and rehabilitation centres, and can be completed by the majority of individuals with SCI. The purpose of this study was to design a submaximal single-stage arm ergometer test (SSSAET) for use in individuals with SCI, and to determine the test-retest reliability and criterion validity of this exercise test. Methods: Thirty subjects with SCI were evaluated using the American Spinal Injury Association (ASIA) scale, isometric strength testing, a physical activity questionnaire, the S S S A E T , and a V0 2 peak test. To determine the test-retest reliability of the S S S A E T , subjects completed the S S S A E T on two days, separated by 1 week. Criterion validity was determined by comparing the results of the S S S A E T with V0 2 peak . Results: A l l subjects were able to complete the S S S A E T . Test-retest reliability of steady state V 0 2 and heart rate (HR) during the S S S A E T were excellent; ICC=0.81 and 0.90, respectively. Examination o f Bland-Altman plots showed acceptable variability between the S S S A E T outcomes on the two testing occasions. The correlation between V0 2 peak and S S S A E T V 0 2 was excellent (r=0.92), while those between V0 2 peak and S S S A E T H R (r=0.63) and V0 2 peak and S S S A E T power output (PO) (r=0.73) were good. 34 Conclusions: This study demonstrated that the S S S A E T has acceptable values for test-retest reliability and criterion validity. Further testing is necessary before the S S S A E T wi l l be ready for implementation as a clinical tool to assess baseline and changes in cardiovascular fitness in individuals with SCI. 35 3.2 Introduction With more than 36,000 Canadians living with a SCI (Canadian Paraplegia Association 1997) and the life expectancy of these individuals closely resembling that of the general population (DeVivo et al 1999; Krause et al. 2004), chronic diseases have become more prevalent in this population, and the predominant cause o f death has shifted from genitourinary infections to respiratory and cardiovascular diseases (DeVivo et al. 1999; Frankel et al. 1998; Soden et al. 2000). Studies have shown that the prevalence of coronary artery disease in individuals with SCI is at least as high as in the general population (Yekutiel et al 1989; Bauman et al 1992). Consequently, physical fitness needs to be better monitored in individuals with SCI, in part because o f its ability to predict cardiovascular disease risk. Relative to the general population, most individuals with SCI have reduced cardiovascular fitness (VG^peak) (Davis 1993) and a diminished physical work capacity (Hopman et al. 1998). Inactivity and low VC»2peak are modifiable risk factors associated with cardiovascular disease (American College of Sports Medicine 2000). B y improving VChpeak in individuals with SCI, both the risk for cardiovascular disease (Dearwater et al. 1986) and physical strain during activities o f daily living can be decreased (Janssen et al. 1996). Protocols for assessing VChpeak for individuals with SCI in laboratory settings are highly established (Martel et al. 1991; Walker et al. 1986), but costly specialized equipment and trained personnel are required to conduct these tests. 36 Submaximal tests have been used widely in able-bodied populations to estimate cardiovascular fitness (Noonan and Dean 2000), but as most involve lower extremity exercise, there are few appropriate tests that can be completed by individuals with SCI. A number of submaximal tests designed for individuals with SCI (Franklin et al. 1990; Kofsky et al. 1983; Longmuir and Shephard 1993; 1995; Rhodes et al. 1981), but each has limitations to widespread use. A n arm ergometer equivalent to the Canadian Aerobic Fitness Test ( C A F T ) (Longmuir and Shephard 1993) was not feasible for individuals with lower limb disabilities because of the high cycling cadences required to complete the test (Longmuir and Shephard 1995). Twelve minute wheeling tests detailed by DiCarlo (1988), Dwyer and Davis (1993), Franklin et al. (1990), and Rhodes et al. (1981) all require large 200 metre tracks, which are not typically available clinically. Finally, a three-stage submaximal arm ergometer test was designed to predict VChpeak in individuals with SCI, but this test was found to be only moderately correlated to measured VChpeak (Kofsky et al. 1983). Despite the studies that have proposed submaximal arm exercise tests, the need remains for a test that is inexpensive, simple to administer in clinics and rehabilitation centres, and that can be completed by individuals with both paraplegia and tetraplegia. In this study, the submaximal single-stage arm ergometer test (SSSAET) is being proposed as a new test to assess cardiovascular fitness in individuals with SCI. The S S S A E T w i l l involve six minutes of submaximal arm ergometry at a constant P O . A s steady state physiological responses are typically seen within two to three minutes of submaximal exercise (Hagberg et al. 1978; Whipp and Wasserman 1972), six minutes was chosen as it would il l ici t steady state exercise, 37 yet not be so long as to fatigue an untrained individual. A single stage test was chosen as it would be simple to administer clinically, and require less of the clinician's time. Thus, the purpose of this study was to design a S S S A E T for use in individuals with SCI, and to determine the test-retest reliability and criterion validity of this exercise test. 3.3 Methods 3.3.1 Subjects Adults with SCI were recruited on a volunteer basis by therapists, a mail-out to past patients from a local rehabilitation centre, and through advertisements placed in a rehabilitation centre and SCI newsletter (Appendix B) . Screening o f potential subjects was done via a telephone interview to determine i f potential subjects 1) had a traumatic SCI at least six months ago; 2) were between 18 and 50 years of age; 3) used a manual or power wheelchair for daily mobility; and 4) were able to independently push an arm cycle ergometer. Individuals were excluded from participating in this study i f they had a previous myocardial infarction (one person). The Physical Activities Readiness Questionnaire (Thomas et al. 1992) (see Appendix C) was administered over the telephone to help decide whether or not it was safe for potential subjects to exercise. Eligible subjects gave informed, written consent (see Appendix D) to participate in this study. Ethical approval for this study was obtained from the University of British Columbia and G F Strong Rehab Centre ethics committees. 38 Sample size calculations were done and are attached in Appendix E . For the validity component of the study it was found that for a two-tailed test with a = 0.05, a power of 0.80 and a desired effect size of 0.5, 28 subjects were required. Cognitive impairment was assessed when potential subjects first arrived at the laboratory using the Cognitive Capacity Screening Examination (CCSE) (Jacobs et al. 1977; Kaufman et al. 1979) (see Appendix F). N o subjects were identified as having a cognitive impairment (as indicated by a score of less than 24 out of 30). The psychometric properties of the C C S E and the other assessment tools used in this study are presented i n Appendix N . Classification of SCI: The A S I A assessment was used to classify the completeness of each subjects SCI, as well as to determine their motor and sensory function (ASIAyinternational Medical Society of Paraplegia 2000) (see Appendix G). Physical activity level: The physical activity level of all subjects was assessed using the Physical Activi ty Scale for Individuals with Physical Disabilities (PASIPD) (Washburn et al. 2002) (see Appendix H). The P A S I P D is a self-report questionnaire that uses an estimate of the number of days per week and hours per day spent in different leisure, household and occupational activities over the past seven days. Total scores are calculated as the sum of the average hours per day multiplied by a metabolic equivalent for all twelve items. 39 Strength: Upper extremity isometric muscle strength was measured using hand-held dynamometry (Nicholas M M T ; Lafayette Instrument; Lafayette, IN). Three maximal voluntary contractions of the elbow flexors and extensors, shoulder flexors and extensors and wrist flexors and extensors were performed bilaterally. Each effort was held for 3 seconds, with at least 30 seconds of rest between trials. The 3 trials were averaged to obtain a mean score for each muscle group. A l l measurements were taken with the subject seated in their wheelchair, using standard arm positioning (see Appendix I). Mobility device: Independence in wheeled mobility was evaluated using a pilot 9-category wheeled mobility classification scale for individuals with SCI. Categories ranged from full time power wheelchair users to full time ambulators. Table 3.1 describes each o f the categories. 3.3.2 Protocol For both the S S S A E T and cardiovascular fitness test, subjects wore a face mask while respiratory variables (VO2, VCO2, ventilation (VE), respiratory exchange ratio (RER)) were continuously measured by a portable metabolic unit performing breath-by-breath gas analysis (Cosmed K 4 b 2 system; C O S M E D ; Rome, Italy). Subjects were asked to void their bladders prior to commencing the exercise tests to minimize any episodes of autonomic dysreflexia. Subjects were asked to rate their level of perceived exertion using Borg's (1970) 16-point rate of perceived exertion (RPE) scale immediately following the tests (see Appendix J). Blood pressure (BP) was recorded at rest, immediately following exercise and throughout 40 recovery to ensure B P returned to baseline values following the exercise tests. Blood lactate measurements were taken at rest and at the end of the exercise tests using a drop o f blood collected from a finger-prick (see Appendix K for protocol). For subjects with insufficient hand grip, elastic straps were used to secure their hands to the handles o f the arm ergometer. Table 3.1 Wheeled mobility categories Category Description 1 Relies fully on power wheelchair 2 Relies primarily on a power wheelchair for community mobility; uses manual wheelchair for exercise only 3 Relies primarily on a power wheelchair for community mobility; uses manual wheelchair for some household activities 4 Relies primarily on manual wheelchair; relies on power wheelchair or assistance with long distances or uphill 5 Relies fully on manual wheelchair and is independent in all home and community activities 6 Relies primarily on manual wheelchair; able to walk for exercise only at home 7 Able to use walking for some household activities, but uses a wheelchair in the community 8 Can walk independently for most activities; relies on a manual wheelchair for long distances 9 Walks independently for all household and community activities 41 SSSAET: Subjects completed a single, 6-minute stage of submaximal exercise on an arm cycle ergometer (Monark Rehab Trainer 88IE; Vansbro, Sweden). A n individual P O was subjectively selected for each subject based on their muscle strength, A S I A motor score and physical activity level. The P O was chosen with the aim of eliciting either a steady state H R of 60-70% of age-predicted maximum H R (for subjects with low level paraplegia) or a rating of 11-15 on Borg's (1970) R P E scale (for subjects with tetraplegia or high level paraplegia). H R was continually recorded using a chest H R monitor (Polar A 3 ; Polar Electro; Woodbury, N Y ) . Approximately one week after the initial S S S A E T , subjects were invited to return to complete a second S S S A E T . One week after the second test, each subject underwent a V02peak test on an arm ergometer. Peak oxygen consumption: To measure V02peak, subjects performed a symptom-limited graded arm cycle ergometer test on an electronically braked arm ergometer (Excaliber; Lode B . V . Medical Technology; Groningen, Netherlands) in the presence of a physician and a kinesiologist. Cardiac stability and H R were monitored by a physician using a 12-lead electrocardiogram (ECG) (Quark C12; C O S M E D Sri; Rome, Italy) (see Appendix L for electrode placement). Subjects initially sat quietly for two minutes while resting values o f H R and respiratory variables were collected. A r m cycling began without resistance at a comfortable, self-selected cadence (between 60-80 rpm). Following a brief warm up, P O increased in a step protocol by either 5 or 10 Watts (WVmin (5 W/min for subjects with tetraplegia (Lasko-McCarthey and Davis 1991), 10 W/min for subjects with paraplegia 42 (Martel et al. 1991)). Subjects continued to arm cycle until they reached volitional fatigue (i.e. they were not able to maintain a cycling rate of 30 rpm). American College o f Sports Medicine ( A C S M ) Guidelines (2000) were used to determine whether the test should be terminated early: ST-segment depression >2 mm, increasing nervous system symptoms (i.e. ataxia, dizziness), sustained ventricular tachycardia or chest discomfort (see Appendix M for additional details regarding the V02peak testing). 3.3.3 Data analysis Descriptive statistics were calculated for subject characteristics and cardiovascular variables (HR, V0 2 ) during the S S S A E T and V02peak test. Skewness coefficients were calculated and scatter-plots o f variables used in the validity analysis visually inspected to ensure outliner and influential data points did not compromise the results. The final 30 seconds of the physiological data (HR, VO2) during the S S S A E T was averaged to get a single representative steady-state value for each subject. The breath-by-breath data obtained during the V02peak test was averaged at a rate of every 15 seconds to obtain a more accurate measure of V02peak. The highest value of VO2 (in mL/kg/min) obtained in any 15 second interval during the test was considered to be the V02peak. Intraclass correlation coefficients (ICC2,i) and standard error of measurement (SEM) were used to determine the test-retest reliability of steady state VO2 and H R during the 43 S S S A E T . Absolute reliability was evaluated using Bland-Altman plots (Bland and Altaian 1986) to determine how individual scores varied on repeated measurement. Pearson product-moment correlations were used to quantify the relationship between V0 2 peak and steady state V 0 2 , H R and P O during the S S S A E T . A l l statistical analyses were performed using SPSS 11.5 software (Statistical Package for the Social Sciences; Chicago, Illinois) using a significance level of p <0.05 (two-tailed). 3.4 Results Descriptive data for the subject characteristics can be found in Table 3.2. A total o f 30 subjects participated in this study; 13 with paraplegia, and 17 with tetraplegia. Lesion levels are listed in Table 3.3. Subjects had a mean (standard deviation (SD)) age of 36.3 (9.3) years and a mean (SD) time since SCI of 12.0 (9.8) years. Eighty-three percent o f the subjects were male, which is comparable to Canadian statistics (Canadian Paraplegic Association 1997). Subjects in this study ranged from full-time power wheelchair users to individuals that were able to ambulate for exercise. 44 Table 3.2 Subject characteristics (n=30) Variables N Mean (SD) Range Sex (M/F) 25/5 Age (years) 36.3 9.3 . 19-49 Time since injury (years) 12.0 9.8 1-34 A S I A Grade (A/B /C /D) 22/7/0/1 A S I A Motor Score (0-100) 41.2 16.7 19-75 P A S I P D score 16.5 9.8 1.0-38.7 Wheeled mobility category (1/3/4/5/6) 2/1/11/15/1 Table 3.3 Subject lesion levels (number per level) Cervical Thoracic Lumbar C4 = 6 TI = 1 L 2 = 2 C5 = 3 T3 = 1 L3 = 1 C6 = 5 T4 = 2 C7 = 3 T 7 = 1 T10 = l T i l =3 T12 = l 45 3.4.1 Peak oxygen consumption The mean (SD) VC^peak value for all subjects was 18.6 (8.4) mL/kg/min, with the range extending from 6.5 to 38.1 mL/kg/min (Table 3.4). The peak H R averaged 129 (29) beats/min, and the mean peak P O attained was 60.2 (36.0) W . Subjects in this study had a wide range of fitness levels, and there was overlap in the physiological responses to exercise between subjects with paraplegia and tetraplegia. During both the V02peak test, and the S S S A E T , 15 subjects required their hands to be secured to the handles of the arm ergometer with elastic straps. No V02peak tests were terminated early because of adverse effects or contraindications. One subject experienced self-reported "mi ld" autonomic dysreflexia mid-way through the test, which presented as a rapid decrease in H R o f 20 beats/min. Seven subjects reported mild light-headedness upon cessation of cycling, and two experienced muscle spasms at low PO's that briefly interrupted their cycling cadence. 3.4.2 SSSAET A l l subjects were able to complete the S S S A E T . Four subjects experienced mild muscle spasms during their cycling that briefly interrupted their cycling cadence. The mean (SD) steady state VO2 value was 13.1 (4.2) mL/kg/min, with the range extending from 6.3 to 22.9 mL/kg/min (Table 3.5). H R averaged 103 (21) beats/min, and the mean P O was 27.8 (17.0) W . Similar to that seen in the V02peak test, there was overlap in the both the PO and physiological responses of the subjects with paraplegia and tetraplegia. 46 Table 3.4 Values during the VChpeak test Variables Mean SD Range Peak PO (W) 60.2 36.0 20-160 Peak H R (beats/rnin) 129 29 75-183 Percent H R maximum 1 70.1 14.0 43.6-97.3 Peak V E (L/min) 42.8 19.5 18.0-113.1 V02peak (mL/kg/min) 18.6 8.4 6.5-38.1 V02peak (L/min) 1.33 0.52 0.74-2.81 Peak R E R 1.14. 0.09 0.97-1.34 Blood lactate (mmol/L) 2 6.6 2.8 2.3-15.1 1 Based on 220-age prediction equation 2 Only 27 of 30 subjects had their blood lactate tested Table 3.5 Steady state values during the S S S A E T Variables Mean SD Range S S S A E T P O (W) 27.8 17.0 10-60 H R (beats/min) 103 21 61-142 Percent H R maximum 1 56.0 10.2 35.7-75.7 V E (L/min) 25.0 5.7 14.7-39.8 V 0 2 (mL/kg/min) 13.1 4.2 6.3-22.9 V 0 2 (L/min) 0.95 0.28 0.55-1.61 Percent V02peak 74.5 13.0 51.0-97.8 R E R 0.89 0.07 0.76-1.04 Blood lactate (mmol/L) 2 3.0 1.3 1.0-6.0 Based on 220-age prediction equation 2 Only 28 of 30 subjects had their blood lactate tested Reliability: Twenty of the 30 subjects (8 with paraplegia, 12 with tetraplegia) completed the SSSAET on a second occasion, approximately 1 week after the first test. Steady state ICC's for HR and VO2 were 0.90 and 0.81, respectively (Table 3.6, Figure 3.1 and Figure 3.2). The Bland-Altman method (Bland and Altman 1986) showed minimal differences between mean (SD) HR at time 1 (104 (23) beats/min) and time 2 (104 (20) beats/min) for the reliability sample. The mean (SD) difference between time 1 and time 2 was 0 (10) beats/min. As can be seen in Figure 3.3, all but one data point fell within 2 SD of the mean difference, and the data points are equally distributed above and below the mean difference line (11 above, 8 below, and 1 on the line). The outlying data point was an individual with tetraplegia. Test-retest reliability was recalculated without this outlier, and the ICC increased to 0.92 (95% CI 0.81-0.97). Similarly, during the SSSAET minimal differences were seen between mean (SD) V 0 2 at time 1 (12.64 (3.71) mL/kg/min) and time 2 (12.26 (3.10) mL/kg/min) for the reliability sample. The mean (SD) difference between time 1 and time 2 was -0.44 (2.07) mL/kg/min (Figure 3.4). Once again, there is only one data point outside 2 SD of the mean difference, and the data points are equally distributed above and below the mean difference line (11 above and 9 below). This outlier was once again an individual with tetraplegia, but a different subject. With this outlier removed, the ICC for V 0 2 increased to 0.86 (95% CI 0.67-0.94). 48 150 • | 130 1 1 1 0 J2 £ 90 CM © 70 50 i Subjects with Tetraplegia - Subjects with Paraplegia o o • • © • • © 50 70 90 110 130 150 Test 1 HR (beats/min) Figure 3.1 Scatter-plot comparing HR during SSSAET test 1 and test 2 • Subjects with Tetraplegia © Subjects with Paraplegia 10 15 20 Test 1 V02 (mUkg/min) 25 Figure 3.2 Scatter-plot comparing VO2 during SSSAET test 1 and test 2 Table 3.6 Test-retest reliability of H R and V 0 2 i cc 2 1 SEM 95% CI H R 0.90 7.12 0.75-0.96 V 0 2 0.81 1.62 0.58-0.92 :E 30 ->. s 20 -to 10 -n • UL 0 -I • -10 -V) -20 -a. -30 --X 60 I Subjects with Tetraplegia > Subjects with Paraplegia Mean + 2*SD — Mean _# Mean-2*SD 80 100 120 140 160 Figure 3.3 Bland Altaian plot of difference in S S S A E T H R between time 1 and time 2 versus average H R from time 1 and time 2 c E 4 - r I Subjects with Tetraplegia > Subjects with Paraplegia Mean + 2*SD 2 -0 -•--2 -4 -6 6 10 12 14 16 18 Mean - Mean - 2*SD 20 Figure 3.4 Bland Altaian plot of difference in S S S A E T V 0 2 between time 1 and time 2 versus average V 0 2 from time 1 and time 2 50 Validity: Using Pearson's correlations, an excellent, positive, linear correlation was found between the SSSAET V O 2 and V0 2peak (r=0.92) (Figure 3.5), while good correlations were found between SSSAET PO and V0 2peak (r=0.73) (Figure 3.6) and SSSAET IIR and V0 2peak (r=0.63) (Figure 3.7), Selected results with subjects split into two groups, those with tetraplegia and those with paraplegia, are presented in Appendix O. • Subjects with Tetraplegia © Subjects with Paraplegia 5 10 15 20 SSSAET V02 (mUkg/min) 25 Figure 3.5 Scatter-plot comparing V 0 2 during the SSSAET and V0 2peak (r=0.92) 51 40 I 30 | O) ••§. 20 ro <D Q. CS o > 10 0 • Subjects with Tetraplegia •• Subjects with Paraplegia o '•a o 1 • o • • "1 m i e G a 1 « m m 20 40 60 SSSAET PO(W) 80 Figure 3.6 Scatter-plot comparing P O during the S S S A E T and V02peak (r=0.73) • Subjects with Tetraplegia * Subjects with Paraplegia 50 70 90 110 130 150 SSSAET HR (beats/min) Figure 3.7 Scatter-plot comparing H R during the S S S A E T and VOapeak (r=0.63) 3.5 Discussion Demographic variables (age, sex, time since injury, level of injury) were comparable to Canadian statistics (Canadian Paraplegic Association 1997). The P A S I P D is a fairly new measurement tool used for the evaluation of physical activity level of individuals with physical disabilities, so limited data is available for comparison. The mean P A S I P D score o f the subjects in this study was comparable to that reported by Washburn et al. (2002) in individuals with a variety of locomotor disabilities (including SCI). Functional walking categories described by Perry et al. (1995) were modified to describe levels of wheelchair use. This new categorical scale was able to provide a description o f subjects' independence in wheeled mobility. A s this study only recruited wheelchair users that were able to independently cycle an arm ergometer, it is appropriate that the majority of subjects were described by categories 4 and 5 (independent manual wheelchair users who do and do not require assistance with wheeling long distances or uphill). No subjects were described by categories 7, 8, or 9, as these categories describe full-time ambulators, and not wheelchair users. The use of this scale is promising as a tool to describe the wheelchair use characteristics of different populations, although further research with a broader range of subjects is necessary to determine i f the initial categories are sufficient to describe all wheeled mobility levels. The V02peak values found in this group o f SCI subjects were similar to others previously reported in the literature (Courts et al. 1983; Janssen et al. 2002) indicating that this sample is 53 representative of the general population of individuals with SCI. This study included individuals with diverse activity levels ranging from sedentary individuals using power wheelchairs to international calibre wheelchair athletes. Using normative categories that were developed from the 20 t h percentiles of V0 2 peak values from 146 men with SCI (Janssen et al. 2002), the subjects from this study were categorized as follows: for subjects with tetraplegia, 1 poor, 1 fair, 6 average, 6 good and 3 excellent; for subjects with paraplegia, 2 poor, 4 fair, 3 average, 1 good and 3 excellent. The V0 2 peak values used by Janssen et al. (2002) to develop the normative categories are from only male subjects, with 40% o f them being athletes. It is likely that the 'normative' V0 2 peak values used to categorize individuals are higher than the true values of the general population of individuals with SCI, thus V 0 2 p e a k classification of subjects in this study may be underestimated. A l l subjects were able to complete 6 minutes of arm ergometry exercise at an individually selected submaximal PO. During the S S S A E T , subjects exercised at an average of 74.5% of V0 2 peak and at 56% of their age-predicted maximum H R , indicating that the exercise was aerobic. Blood lactate immediately following the S S S A E T averaged 3.0 mmol/L. The onset of blood lactate accumulation, or the transition to anaerobic exercise, is said to take place when blood lactate concentrations rise above 4.0 mmol/L (Yoshida et al. 1987), so our value o f 3.0 mmol/L provides further confirmation that aerobic exercise was occurring during the S S S A E T . Based on the magnitude o f acceptable reliability values presented by Andresen (2000) and Fleiss (1981), H R and V 0 2 measured during the S S S A E T have excellent test-retest 54 reliability. Visual inspection of the Bland-Altman plots reveals fairly equal distribution o f test-retest differences above and below zero, suggesting minimal bias with repeated testing. For both H R and VO2, only one o f the 20 subjects in the reliability sample fell outside 2 S D of the mean difference, indicating limited test-retest variation for both variables (Bland and Altman 1986). Both H R and VO2 have well established relationships with PO, so it is not surprising that reliability was high. The S S S A E T was designed as a submaximal cardiovascular fitness test, and thus it needed be validated against the gold standard of cardiovascular fitness testing, the V02peak test. The correlation between V02peak and S S S A E T VO2 was excellent (r=0.92), indicating that those subjects with a high submaximal VO2, had a high V02peak. Submaximal P O and V0 2 peak had a lower correlation (r=0.73). It is not surprising that this correlation was weaker, as up to nine subjects cycled at the same P O for the S S S A E T , and all did not have the same absolute V02peak. The correlation between submaximal H R and V0 2 peak was also lower (r=0.63). The S S S A E T was designed to have subjects cycle while maintaining a constant P O at 60-70% of their age-predicted maximum H R . A s this target H R value is based solely on age, two individuals o f the same age but different cardiovascular fitness levels would both be exercising at a similar submaximal H R . The same submaximal H R would be associated with very different V02peak values. Thus the correlation between S S S E A T H R and V02peak is not a true measure o f validity, and was not expected to be high. One of the difficulties of conducting the S S S A E T was determining an appropriate submaximal P O for each subject. In this study, PO for the S S S A E T was selected subjectively 55 based on subjects A S I A motor score, muscle strength and physical activity level. I f the initial PO was too high (i.e. subjects could not complete 6 minutes, R P E > 15, and/or H R > 70% age predicted maximum) or too low (i.e. R P E < 11 and/or H R < 60% age predicted maximum), subjects were given a rest period before they attempted a second S S S A E T at an adjusted PO. Retrospectively, separate algorithms were created for individuals with paraplegia and tetraplegia to provide guidelines for S S S A E T P O selection (Figures 3.8 and 3.9). I f these algorithms had been used to predict the PO's for the subjects in this study, 11 o f the 17 subjects with tetraplegia (65%), and 11 of the 13 subjects with paraplegia (85%) would have had their PO set appropriately on the first attempt. Diagnosis: TETRAPLEGIA Set PO to 10 W if: Set P O to 15 W if: Set PO to 20W if: Power wheelchair user Manual wheelchair user Manual wheelchair user or and <Grade 4 wrist extension Grade 5 wrist flexion and Physically active If 6-min cannot be completed, or RPE >15, rest 10 min & decrease PO by 5 W; continue to decrease PO by 5 W until RPE is between 11 and 15 If after 6-min RPE is between 11 and 15, test is complete If after 6-min RPE is <ll,rest 10 min & increase PO by 5 W;continue to increase PO by 5 W until RPE is between 11 and 15 Figure 3.8 S S S A E T P O selection algorithm for individuals with tetraplegia 56 Diagnosis: PARAPLEGIA Set PO to 30 W if: Set PO to 40 W if: Set PO to 50 W if: Set PO to 60 W if: Female: inactive Female: active Female: competitive athlete Male: competitive athlete Male: inactive Male: recreational athlete If 6-min cannot be completed, or RPE >15, rest 10 min & decrease PO by 10 W; continue to decrease PO by 10 W until RPE is between 11 and 15 If after 6-min RPE is between 11 and 15, test is complete If after 6-min RPE i s< l l , rest 10 min & increase PO by 10 W; continue to increase PO by 10 W until RPE is between 11 and 15 Figure 3.9 S S S A E T P O selection algorithm for individuals with paraplegia The S S S A E T is a practical test that can be administered to individuals of all fitness levels. Unlike the modified arm C A F T , all subjects recruited for this study were able to complete the S S S A E T . Functionally, all subjects had a minimum manual muscle testing score o f grade 4 for wrist extension. The equipment required to conduct the S S S A E T is minimal (arm ergometer, H R monitor, R P E scale), and all pieces are available in most rehab settings. For the S S S A E T to be used clinically, clinicians first need to determine the appropriate P O for an individual to be exercising at using the algorithms provided in Figures 3.7 and 3.8. Baseline outcome variables would be determined by recording clients exercising H R during the final 30 seconds o f the 6 minute test, and taking their R P E at the end of the test. At a later 57 time (i.e. after an intervention aimed at increasing cardiovascular fitness) the S S S A E T should be re-administered at the same P O that was used pre-intervention. A decrease in H R and/or R P E may indicate an increase in V0 2 peak, while an increase in H R and/or R P E may indicate a decrease in V02peak. 3.6 Summary In summary, the steady state H R and VO2 responses obtained during the S S S A E T are reliable, and the criterion validity o f the S S S A E T for assessing cardiovascular fitness in individuals with SCI is excellent. With further testing, the S S S A E T can be implemented as a clinical tool to assess baseline and changes in cardiovascular fitness in individuals with SCI. 58 Chapter 4: General Discussion 4.1 Overview With a high incidence o f cardiovascular diseases in individuals with spinal cord injury (SCI), it is important to have an accurate and reliable measurement tool to assess cardiovascular fitness level (V02peak) to aid in risk assessment of cardiovascular diseases. The work of this thesis has identified the strengths and weaknesses of existing submaximal exercise tests for individuals with SCI. As well , a new submaximal single-stage arm ergometer test (SSSAET) has been presented, and its reliability and validity evaluated in individuals with SCI. 4.2 Evaluation of the SSSEAT Several submaximal tests for evaluating cardiovascular fitness in individuals with SCI have been described in the literature. Through a systematic review, a variety o f predictive and performance based submaximal arm exercise tests were identified and evaluated for their feasibility, reliability, validity and responsiveness. The review identified a number of submaximal tests, and although some initially appeared to be useful for the assessment of cardiovascular fitness in individuals with SCI, all had methodological and/or validation limitations. Thus, it was concluded that the need remained for a submaximal arm exercise test that could be used to predict cardiovascular fitness in individuals with SCI. 59 Accordingly, the S S S A E T was designed to assess cardiovascular fitness in individuals with SCI using a single stage of arm cycle ergometry at a submaximal power output (PO). The S S S A E T was found to be both reliable and valid in a group of 30 individuals with SCI. A l l individuals were able to complete the test without incident, indicating the test is feasible. The excellent one week test-retest reliability for submaximal VO2 and H R was not surprising, as these variables have fairly consistent responses to steady state submaximal exercise. Criterion validity, as measured by the relationship between submaximal VO2 and V02peak, was also excellent. This is the first submaximal exercise test for individuals with SCI that has shown to be reliable, valid and feasible. The subject sample used in this study was more heterogenous compared to samples used to evaluate other submaximal tests in individuals with SCI. Those with complete and incomplete spinal lesions, those who use manual and power wheelchairs, and those with a wide range of physical activity level (sedentary, recreationally active and elite athletes), all participated in this study. The range of both impairment and activity level of subjects in this study increases the generalizability of the results and demonstrates the feasibility of using this test in many individuals with SCI. It is possible; however, that the wide range of responses to the S S S A E T may have inflated the intraclass correlation coefficients that described the reliability o f the test. The information gained from exercise tests such as the S S S A E T can be valuable for activity counselling, exercise prescription, cardiovascular disease risk assessment, and as 60 positive motivational feedback for individuals already taking part in an exercise program to increase cardiovascular fitness. 4.3 Clinical implications A s the S S S A E T has been shown reliable and valid, its limitations as a clinical exercise test must be discussed. In its current form, the S S S A E T does not provide specific information about an individuals' cardiovascular fitness level. It simply measures an individuals' H R response to arm cycling at a steady-state submaximal PO. The H R response is reliable, so a change in the H R response to arm cycling at the same P O at a later date may be indicative of a change in cardiovascular fitness. A n increase in H R while arm cycling at the same P O may indicate a decrease in cardiovascular fitness, while a decrease in H R may signify an increase in cardiovascular fitness. The ability of the S S S A E T to detect change has not yet been evaluated. Similar to the S S S A E T , the 3-stage arm ergometer test designed by Kofsky et al. (1983) uses the linear relationship between H R and VO2 to assess cardiovascular fitness. Hicks et al. (2003) found the Kofsky test to be responsive to a change in cardiovascular fitness, so it is anticipated that the S S S A E T wi l l also be able to detect change. Based on the evaluation of previous literature, recommendations were made in Chapter 2 to use the Kofsky (1983) test to assess cardiovascular fitness in individuals with paraplegia, and the wheeling test (Rhodes et al. 1981) for individuals with tetraplegia. With further testing o f the S S S A E T , it is anticipated that it w i l l become the optimal submaximal test for evaluating cardiovascular fitness in all individuals with SCI. 61 Instructions to a clinician wishing to use the S S S A E T may be as follows: • Use the algorithms provided in Figures 3.8 and 3.9 to determine an appropriate P O for the S S S A E T . • Monitor the individual with SCI as they complete 6 minutes of arm cycling at the appropriate PO. During the final 30 seconds of the test, H R should be recorded. A t the 6 minute mark, a rating of perceived exertion (RPE) should be taken. • Prescribe an intervention with the goal of increasing cardiovascular fitness. • Re-administer the S S S A E T after the intervention has been completed. • A decrease in H R and/or R P E may indicate an improvement in V02peak, while an increase may indicate a decrease in V02peak. With a tool to measure an individuals' progression through a cardiovascular fitness training program, clinicians wi l l be better equipped to set exercise goals for individuals with SCI and monitor their progress as they work to attain these goals. 4.3.1 Limitations As this test uses the assumption that H R and VO2 have a linear relationship, attempts were made to minimize and/or eliminate factors that influence this relationship. Subjects were asked to refrain from drinking caffeinated and alcoholic beverages and eating food prior to testing, and scheduling was done with the goal of having all visits that a subject made to the lab (2 or 3 visits) be at the same time of day. Food and fluid intake were not specifically 62 monitored; therefore changes in hydration status between the two reliability tests may have affected the reliability values. Subjects for this study were recruited by rehabilitation therapists, through a mail-out to past patients from the local rehabilitation centre, and via advertisements posted in the rehabilitation centre and a SCI newsletter. These individuals were not randomly selected. They were primarily individuals who were already physically active or those who were interested in becoming physically active. Consequently, although individuals with a wide range of activity levels were included in this study, the sample may not have been representative of all individuals with SCI. The C O S M E D K 4 b 2 gas analysis system was used to measure respiratory variables. Several studies have examined the reliability and validity of this system (Duffield et al. 2004; Crandall et al 1994; Lucia et al. 1993; McLaughl in et al. 2001). McLaughl in et al. (2001) found a small, significantly higher (<0.1 L/min) difference between the VO2 measured by the C O S M E D K 4 b 2 system and the Douglas bag method, but concluded that despite this small discrepancy the C O S M E D K 4 b 2 was acceptable for measuring VO2 across a wide range of PO's . On the other hand, Duffield et al. (2004) found the C O S M E D K 4 b 2 system to consistently overestimate both V 0 2 and VCO2. This overestimation may have introduced a systematic bias within the results of this study, but because the same gas analysis system was used for all tests, reliability of VO2 values during the S S S A E T would not have been affected. 63 4.4 Suggested future work This thesis has only begun to evaluate the SSSAET. A number of further studies are recommended: • In a clinical trial aimed to improve cardiovascular fitness in individuals with SCI, the SSSAET should be used to evaluate cardiovascular fitness along with the gold-standard VG^peak test. This study would be designed to assess the responsiveness of the SSSAET by comparing its ability to detect a change in cardiovascular fitness with the VC>2peak test. With the high prevalence of cardiovascular disease in individuals with SCI, it is crucial that research focus on interventions aimed at maximizing the cardiovascular fitness of these individuals. • A large (>50 subjects) cross-sectional study could be done to determine if a regression equation for the prediction of VC»2peak could be developed using demographic variables (e.g. age, ASIA motor score) and SSSAET variables (PO, HR). This may allow cardiovascular fitness to be more precisely predicted. • A cross-sectional study could also be used to assess the reliability and validity of the SSSAET in individuals with other lower limb disabilities. These studies may include individuals with lower limb amputation, post-polio syndrome, cerebral palsy, and individuals with a non-traumatic SCI, and would further increase the generalizability of the SSSAET. 64 4.5 Summary This thesis began by identifying submaximal exercise tests for individuals with SCI, and noted that no test has demonstrated reliability, validity, feasibility and responsiveness. The S S S A E T was then presented as an alternative submaximal exercise test, and testing has shown this test to be reliable, valid and feasible for testing cardiovascular fitness in individuals with SCI. Although further research is necessary to assess its responsiveness, it is anticipated that the S S S A E T wi l l be a useful clinical tool to assess baseline cardiovascular fitness in individuals with SCI, and to monitor any changes that occur in their cardiovascular fitness. 65 REFERENCES 1. American Spinal Injury Association/International Medical Society of Paraplegia. International standards for neurological and functional classification of spinal cord injured patients. Chicago; 2000. 2. American College of Sports Medicine. Guidelines for exercise testing and prescription, 6 t h edition. Baltimore, M D : Lippincott Williams and Wilkens; 2000. 3. Andresen E M . Criteria for assessing the tools of disability outcomes research. A r c h Phys M e d Rehabil 2000; 81(Suppl 2): S15-S20. 4. Astrand PO. Aerobic work capacity in men and women with special reference to age. Acta Physiol Scand 1960; [Suppl 196] 49: 1-92. 5. Barron K W , Blair R W . The autonomic nervous system. In: Cohen H , ed. Neuroscience for rehabilitation, 2 n d ed. Philadelphia, P A : Lippincott, Will iams and Wilkins; 1999: 277-302. 6. Bauman W A , Spungen A M , Raza M , Rothstein F, Zhang R L , Zhong Y G , Tsuruta M , Shahidi R, Pierson R N , Wang J, Gordon S K . Coronary artery disease: metabolic risk factors and latent disease in individuals with paraplegia. M t Sinai J Med 1992; 59(2): 163-168. 7. Bauman W A , Spungen A M . Disorders o f carbohydrate and l ipid metabolism in veterans with paraplegia or quadriplegia: a model of premature aging. Metabolism 1994; 43(6): 749-756. 66 8. Bauman W A , Adkins R H , Spungen A M , Kemp B J , Waters R L . The effect of residual neurological deficit on serum lipoproteins in individuals with chronic spinal cord injury. Spinal Cord 1998;36:13-17. 9. Bland J M , Altman D G . Statistical methods for assessing agreement between two methods o f clinical measurement. Lancet 1986; 1(8476): 307-310. 10. Bohannon R W , Andrews A W . Interrater reliability of hand-held dynamometry. Phys Ther 1987; 67(6): 931-933. 11. Borg G . Perceived exertion as an indicator of somatic stress. Scand J Rehabil Med 1970; 2: 92-98. 12. Borg G . Psychosocial bases o f perceived exertion. M e d Sci Sports Exerc 1982; 14(5): 377-381. O .Brenes G , Dearwater S, Shapera R, LaPorte R E , Collins E . High density lipoprotein cholesterol concentrations in physically active and sedentary spinal cord injured patients. Arch Phys M e d Rehabil 1986; 67(7): 445-450. 14. Buchholz A C , McGil l ivray C F , Pencharz P B . Physical activity levels Eire low in free-living adults with chronic paraplegia. Obes Res 2003; 11(4): 563-570. 15. Canadian Paraplegic Association. Workforce participation survey o f Canadians with spinal cord injuries. Ottawa, O N : Canadian Paraplegic Association; 1997. 16. Cariga P, Ahmed S, Mathias C J , Gardner B P . The prevalence and association of neck (coat-hanger) pain and orthostatic (postural) hypotension in human spinal cord injury. Spinal Cord 2002; 40(2): 77-82. 17. Cohen J. Statistical power analysis for the behavioural sciences, 2 n d ed. Hillsdale, N J : Lawrence Erlbaum Associates; 1988. 67 18. Cohen M , Bartko JJ. Reliability of ISCSCI-92 for neurological classification of spinal cord injury. In: Reference manual for the international standards for neurological and functional classification of spinal cord injury. American Spinal Injury Association, 1994. p.59-65. 19. Coutts K D , Rhodes E C , McKenzie D C . Maximal exercise responses of tetraplegics and paraplegics. J App l Physiol: Respirat Environ Exercise Physiol 1983; 55(2): 479-482. 20. Crandall C G , Taylor S L , Raven P B . Evaluation of the Cosmed K 2 portable telemetric oxygen uptake analyzer. M e d Sci Sports Exerc 1994; 26(1): 108-111. 21. Dallmeijer A J , Hopman M T E , van der Woude L H V . Lip id , lipoprotein, and apolipoprotein profiles in active and sedentary men with tetraplegia. Arch Phys M e d Rehabil 1997; 78: 1173-1176. 22. Davis G M . Exercise capacity of individuals with paraplegia. M e d Sci Sports Exerc 1993; 25(4): 423-432. 23. Dearwater SR, Laporte R E , Robertson RJ , Brenes G , Adams L L , Becker D . Activi ty in the spinal-cord injured patient: an epidemiologic analysis of metabolic parameters. M e d Sci Sports Exerc 1986; 18(5): 541-544. 24. Dela F, Mohr R, Jensen C M R , Haahr H L , Secher N H , Biering-Sorensen F , Kjaer M . Cardiovascular control during exercise: Insights from spinal cord-injured humans. Circulation 2003; 107: 2127-2133. 25. Demirel S, Demirel G , Tuket T, Erk O, Yi lmaz H . Risk factors for coronary heart disease in patients with spinal cord injury in Turkey. Spinal Cord 2001; 39(3): 134-138. 26. DeVivo M J , Black K J , Stover SL . Causes of death during the first 12 years after spinal cord injury. Arch Phys M e d Rehabil 1993; 74: 248-254. 68 27. DeVivo M J , Krause JS, Larnrnertse D P . Recent trends in mortality and causes of death among persons with spinal cord injury. Arch Phys M e d Rehabil 1999; 80(11): 1411-1419. 28. DiCarlo SE. Effect of arm ergometry training on wheelchair propulsion endurance of individuals with quadriplegia. Phys Ther 1988; 68(1): 40-44. 29. Drory Y , Ohry A , Brooks M E , Dolphin D , Kellermann JJ. A r m crank ergometry in chronic spinal cord injured patients. Arch Phys M e d Rehabil 1990; 71(6): 389-392. 30. Duffield R, Dawson B , Pinnington H C , Wong P. Accuracy and reliability of a Cosmed K4b2 portable gas analysis system. J Sci M e d Sport 2004; 7(1): 11-22. 31. Dwyer G B , Davis R W . The relationship between a twelve minute wheelchair push test and VC»2peak in women wheelchair athletes. Sports Med, Training and Rehab 1997; 8(1): 1-11. 32. E l Masry W S , Tsubo M , Katoh S, E l Mi l igu i Y H S , Khan, A . Validation of the American Spinal Injury Association (ASIA) Motor Score and the National Acute Spinal Cord Injury Study (NASCIS) Motor Score. Spine 1996; 21(5): 614-619. 33. Flandrois R, Grandmontagne M , Gerin H , Mayet M H , Jehl JL , Eyssette M . Aerobic performance capacity in paraplegic subjects. Eur J Appl Phyiol 1986; 55: 604-609. 34. Fleiss JL . Statistical methods for rates and proportions. New York, N Y : Wiley; 1981. 35. Frankel H L , C o l l JR, Charlifue S W , Whiteneck G G , Gardner B P , Jamous M A , Krishnan K R , Nuseibeh I, Savic G , Sett P. Long-term survival in spinal cord injury: a fifty year investigation. Spinal Cord 1998; 36(4): 266-274. 69 36. Franklin B A , Swantek K I , Grais S L , Johnstone K S , Gordon S, Timmis G C . Field test estimation of maximal oxygen consumption in wheelchair users. Arch Phys M e d Rehabil 1990;71:574-578. 37. Freyschuss U , Knutsson E . Cardiovascular control in man with transverse cervical cord lesions. Life Sci 1969; 8(1): 421-424. 38. Glaser R M , Sawka M N , Brune M F , Wilde SW. Physiological responses to maximal effort wheelchair and arm crank ergometry. J App l Physiol 1980; 48(6): 1060-1064. 39. Hagberg J M , Al len M , Seals D R , Hurley B F , Ehsani A A , Holloszy JO. A hemodynamic comparison of young and older endurance athletes during exercise. J App l Physiol 1985; 58(6): 2041-2046. 40. Hagberg J M , mullen JP, Nagle FJ . Oxygen consumption during constant-load exercise. J App l Physiol 1978; 45(3): 381-384. 41. Hicks A L , Martin K A , Ditor DS , Latimer A E , Craven C , Bugaresti J, McCartney N . Long-term exercise training in persons with spinal cord injury: effects on strength, arm ergometry performance and psychological well-being. Spinal Cord 2003; 41(1): 34-43. 42. Hoffman M D . Cardiorespiratory fitness and training in quadriplegics and paraplegics. Sports Med 1986; 3: 312-330. 43. Hopman M T E , Dueck C , Monroe M , Philips W T , Skinner JS. Limits to maximal performance in individuals with spinal cord injury. Int J Sports M e d 1998; 19: 98-103. 44. Hopman M T E , Verheijen P H E , Binkhorst R A . Volume changes in the legs of paraplegic subjects during arm exercise. J A p p l Physiol 1993; 75(5): 2079-2083. 45. Jacobs JW, Bernhard M R , Delgado A , Strain JJ. Screening for organic mental syndromes in the medically i l l . A n n Intern Med 1977; 86(1): 40-46. 70 46. Janssen T W J , Dallmeijer A J , Veeger H E F , van der Woude L H V . Normative values and determinants o f physical capacity in individuals with spinal cord injury. J Rehabil Res Devel 2002; 39(1): 29-39. 47. Janssen T W J , vanOers C A J M , Rozendaal E P , Willemsen E M , Hollander A P , van der Woude L H V . Changes in physical strain and physical capacity i n men with spinal cord injuries. M e d Sci Sports Exerc 1996; 28(5): 551-559. 48. Janssen T W J , van Oers C A J M , van Kamp GJ , TenVoorde B J , van der Woude L H V , Hollander A P . Coronary heart disease risk indicators, aerobic power, and physical activity in men with spinal cord injuries. Arch Phys M e d Rehabil 1997; 78: 697-705. 49. Kaufman D M , Weinberger M , Strain JJ, Jacobs JW. Detection o f cognitive deficits by a brief mental status examination: The cognitive capacity screening examinations, a reappraisal and a review. Gen Hosp Psychiatry 1979; 1(3): 247-255. 50. K i n g M L , Lichtman SW, Pellicone JT, Close R J , Lisanti P. Exertional hypotension in spinal cord injury. Chest 1994; 106(4): 1166-71. 51. Kirshblum S. New rehabilitation interventions in spinal cord injury. J Spinal Cord M e d 2004; 27(4): 342-350. 52. Kofsky PR, Davis G M , Shephard R J , Jackson R W , Keene G C R . Field testing: assessment o f physical fitness o f disabled adults. Eur J A p p l Physiol 1983; 51: 109-120. 53. Krause JS, Devivo M J , Jackson A B . Health status, community integration, and economic risk factors for mortality after spinal cord injury. Arch Phys M e d Rehabil 2004; 85(11): 1764-1773. 54. Lasko-McCarthey P, Davis J A . Protocol dependency o f V02max during arm cycle ergometry in males with quadriplegia. M e d Sci Sports Exerc 1991; 23(9): 1097-1101. 71 55. Longmuir P E , Shephard RJ . A simple upper body analogue of the Canadian Home Fitness Test for the assessment of mobility-impaired adults. Can J Rehab 1993; 7: 133-141. 56. Longmuir P E , Shephard RJ . Reliability and validity of a modified Canadian Aerobic Fitness Test for individuals with mobility impairments. Adapted Physical Activity Quarterly 1995; 12: 161-175. 57. Lucia A , Fleck SJ, Gotshall R W , Kearney JT. Reliability and validity of the Cosmed K 2 Instrument. Int J Sports Med 1993; 14(7): 380-386. 58. Macsween A . The reliability and validity of the Astrand nomogram and linear extrapolation for deriving VChmax from submaximal exercise data. J Sports M e d Phys Fitness 2001; 41(3): 312-317. 59. Manns PJ, McCubbin JA , Williams DP. Fitness, inflammation and the metabolic syndrome in men with paraplegia. Arch Phys M e d Rehabil 2005; 86: 1176-1181. 60. Martel G , Noreau L , Jobin J. Physiological responses to maximal exercise on arm cranking and wheelchair ergometer with paraplegics. Paraplegia 1991; 29: 447-456. 61. McArdle W D , Katch FI, Katch V L . Exercise Physiology: Energy, nutrition, and human performance, 5 t h edition. Baltimore, M D : Lippincott Williams & Wilkins; 2001. 62. McGlinchey-Berroth R, Morrow L , Ahlquist M , Sarkarati M , Minaker K L . Late-life spinal cord injury and aging with a long term injury: characteristics of two emerging populations. J Spinal Cord Med 1995; 18(3): 183-193. 63. McLaughlin JE, K ing G A , Howley ET, Bassett D R Jr, Ainsworth B E . . Validation of the C O S M E D K 4 b 2 portable metabolic system. Int J Sports M e d 2001; 22: 280-284. 72 64. M c N e i l l A M , Rosamond W D , Girman GJ, Golden S H , Schmidt M I , East H E , Ballantyne C M , Heiss G . The metabolic syndrome and 11-year risk of incident cardiovascular disease in the atherosclerosis risk in communities study. Diabetes Care 2005; 28(2): 385-390. 65. Monroe M B , Tataranni P A , Pratley R, Manore M M , Skinner JS, Ravussin E . Lower daily energy expenditure as measured by a respiratory chamber in subjects with spinal cord injury compared with control subjects. A m J C l i n Nutr 1998; 68(6): 1223-1227. 66. Nobrega A C L , Araiijo C G S . Heart rate transient at the onset o f active and passive dynamic exercise. Med Sci Sports Exerc 1993; 25(1): 37-41. 67. Noonan V , Dean E . Submaximal exercise testing: clinical application and interpretation. Phys Ther 2000; 80(8): 782-807. 68. Noreau L , Proulx P, Gagnon L , Drolet M , Laramee M T . Secondary impairments after spinal cord injury: a population-based study. A m J Phys Med Rehabil 2000; 79(6): 526-535. 69. Noreau L , Vachon J. Comparison of three methods to assess muscular strength in individuals with spinal cord injury. Spinal Cord 1998; 36(10): 716-723. 70. Pare G , Noreau L , Simard C . Prediction o f maximal aerobic power from a submaximal exercise test performed by paraplegics on a wheelchair ergometer. Paraplegia 1993; 31(9): 584-592. 71. Perry J, Garrett M , Gronley J K , Mulroy SJ. Classification of walking handicap in the stroke population. Stroke 1995; 26(6): 982-989. 72. Portney L G , Watkins M P . Foundations o f clinical research: applications to practice. Upper Saddle River, N J : Prentice-Hall, Inc.; 2000. 73 73. Price M J , Campbell IG. Thermoregulatory responses o f spinal cord injured and able-bodied athletes to prolonged upper body exercise and recovery. Spinal Cord 1999; 37(11): 772-779. 74. Pyne D B , Boston T, Martin D T , Logan A . Evaluation o f the Lactate Pro blood lactate analyzer. Eur J App l Physiol 2000; 82(1-2): 112-116. 75. Reaven G . Metabolic syndrome: pathophysiology and implications for management of cardiovascular disease. Circulation 2002; 106: 286-288. 76. Rhodes E C , McKenzie D C , Coutts K D , Rogers A R . A field test for the prediction of aerobic capacity in male paraplegics and quadraplegics. Can J App l Spt Sci 1981; 6(4): 182-186. 77. Robergs R A , Roberts SO. Exercise physiology: Exercise, performance, and clinical applications. Toronto, O N : Mosby-Year Book, Inc.; 1997. 78. Rowell L B , Taylor H L , Wang Y . Limitations to prediction of maximal oxygen intake. J Appl Physiol 1964; 19: 919-927. 79. Schmid A , Huonker M , Barturen J M , Stahl F, Schmidt-Truckass A , Konig D , Grathwohl D , Lehmann M , Keu l J. Catecholamines, heart rate, and oxygen consumption during exercise in persons with spinal cord injury. J App l Physiol 1998; 85(2): 635-641. 80. Schwartz S, Cohen M E , Herbison GJ , Shah A . Relationship between two measures o f upper extremity strength: manual muscle test compared to hand-held myometry. Arch Phys Med Rehabil 1992; 73(11): 1063-1068. 81. Shephard R J . Al ive man: The physiology of physical activity. C h C Thomas, Springfield, 111; 1972. 74 82. Soden R J , Walsh J, Middleton JW, Craven M L , Rutkowski S B , Yeo JD. Causes of death after spinal cord injury. Spinal Cord 2000; 38(10): 604-610. 83. Streiner. D L , Norman GR. Health measurement scales - A practical guide to their development and use. Second Edition. Oxford: Oxford University Press; 1995. 84. Taylor H L , Buskirk E , Henschel A . Maximal oxygen intake as an objective measure of cardio-respiratory performance. J A p p l Physiol 1955; 8(1): 73-80. 85. Thomas S, Reading J, Shephard R J . Revision of the Physical Activity Readiness Questionnaire (PAR-Q) . Can J Sport Sci 1992; 17(4): 338-345. 86. Wadsworth C T , Krishnan R, Sear M , Harrold J, Nielsen D H . Intrarater reliability o f manual muscle testing and hand-held dynametric muscle testing. Phys Ther 1987; 67(9): 1342-1347. 87. Walker R, Powers S. Stuart M K . Peak oxygen uptake in arm ergometry: effects o f testing protocol. Brit J Sports Med 1986; 20(1): 25-26. 88. Washburn R A , Zhu W , McAuley E , Frogley M , Figoni SF. The physical activity scale for individuals with physical disabilities: development and evaluation. Arch Phys M e d Rehabil 2002; 83(2): 193-200. 89. Wecht J M , DeMeersman R E , Weir JP, Spungen A M , Bauman W A , Grimm D R . The effects of autonomic dysfunction and endurance training on cardiovascular control. C l i n AutonRes 2001; 11(1): 29-34. 90. Whipp B J , Wasserman K . Oxygen uptake kinetics for various intensities of constant-load work. J A p p l Physiol 1972; 33(3): 351-356. 91. Wyndham C H . Submaximal tests for estimating maximum oxygen intake. Can Med Assoc J 1967; 96(12): 736-742. 75 92. Yekutiel M , Brooks M E , Ohry A , Yarom J, Carel R. The prevalence of hypertension, ischaemic heart disease and diabetes in traumatic spinal cord injured patients and amputees. Paraplegia 1989; 27: 58-62. 93. Yoshida T, Chida M , Ichioka M , Suda Y . Blood lactate parameters related to aerobic capacity and endurance performance. Eur J A p p l Physiol Occup Physiol 1987; 56(1): 7-11. 94. Zhong Y G , Levy E , Bauman W A . The relationships among serum uric acid, plasma insulin, and serum lipoprotein levels in subjects with spinal cord injury. Horm Metab Res 1995; 27(6): 283-286. 76 APPENDIX A: Systematic review search strategy ( M E D L I N E ) 1. exp P A R A P L E G I A / 2. exp Q U A D R I P L E G I A / 3. paraplS.mp. 4. quadrip$.mp. 5. tetrapl$.mp. 6. exp Spinal Cord Injuries/ 7. SCLmp. 8. or/1-7 9. ((exercise or aerobic or fitness or cardio$) adj5 (test or evaluat$ or measure$)).mp. 10. exp Exercise Test/ 11. exp Physical Fitness/ 12. exp Physical Endurance/ 13. exp E X E R C I S E / or exp E X E R C I S E TEST, C A R D I O P U L M O N A R Y / 14. or/9-13 15. (submax$ or field or predict$).mp. 16. 8 and 14 and 15 77 APPENDIX B: Recruitment advertisements ***RESEARCH STUDY*** Exercise Testing for Individuals with Spinal Cord Injury Persons with spinal cord injury are invited to take part in a study undertaken by the School of Rehabilitation Sciences, University of British Columbia, in conjunction with the GF Strong Rehab Centre. This study will evaluate if a simple arm crank cycling test can be used to predict cardiovascular fitness levels in adults with a spinal cord injury. You will be required to complete a simple arm crank cycling test on two occasions, and undergo a cardiovascular stress test. In addition, you will be required to fill out questionnaires so that we can detenriine if you have any other health-related problems, how often and for how long you use your wheelchair and your involvement in sporting activities. Every subject will be asked to attend 3 testing sessions, each lasting 1 hour, over a 1-month period. You will receive a short summary about your cardiovascular fitness status after the study has been completed. There are no direct benefits to you; however, you will receive an honorarium to help defray the cost of transportation to and from the testing sessions. You are eligible to participate in this study if you meet the following criteria: • Had a traumatic spinal cord injury at least 6 months ago • Are between the ages of 18-50 • Use a manual wheelchair for your daily activities • Are able to independently cycle with your arms • Are medically stable (i.e. no unstable cardiovascular disease) For more information or to participate in this study, contact Adrienne Hoi at the GF Strong Rehab Centre at: 78 Spinal Cord Injury Research Study Persons who have had a spinal cord injury more than 6 months ago are invited to take part in a research study to evaluate physical fitness and wheelchair use. If you use a manual wheelchair and are at least 18 years of age, you may be eligible to participate in this study. An honorarium will be provided. Contact the Rehab Research Lab at the GF Strong Rehab Centre at 6.F. STRONG REHAB CENTRE A jwrt of fh? Vancouver Cwsiai Health Authority 79 APPENDIX C: Physical Activity Readiness Questionnaire . Physics! Acti«ty Reac&ness Questicroiaire - PAR-Q (revised 2002) PAR-Q & YOU {A Q u e s t i o n n a i r e f o r P e o p l e A g e d 1 5 t o 6 9 ) Regular physical activity is fun and healthy, and increasingly more people are starting to become more active every day. Being more active is very sale for most people. However, some people should check with their doctor before they start becoming much more physically active. If you are planning to become much more physically active than you are now, start by answering the seven questions in the box below. If you are between the , ages of 15 and 69, the PAR-Q will tell you if you should check with your doctor before you start. If you are over 69 years of age, and you are not used to being very active, check with your doctor. Common sense is your best guide when you answer these questions. Please read the questions carefully and answer each one honestly: check YES or NO. YES NO • • • • • • • • • • • • • • 1. Has f o u r d o c t o r e v e r s a i d that y o u have a h e a r t c o n d i t i o n a n d that y o u s h o u l d on ly d o phys ica l activity r e c o m m e n d e d by a d o c t o r ? 2 . Do you f e e l p a i n in y o u r c h e s t w h e n y o u d o phys ica l act iv i ty? 3. In the past m o n t h , have you h a d chest pa in w h e n y o u w e r e not d o i n g physical act iv i ty? 4 . Do you l o s e your b a l a n c e b e c a u s e of d i z z i n e s s or d o you ever l o s e c o n s c i o u s n e s s ? 5 . D o y o u have a b o n e o r j o i n t p r o b l e m (for e x a m p l e , b a c k , knee or hip) that c o u l d be m a d e w o r s e by a change in your phys ica l act iv i ty? 6. Is your doc tor cur ren t ly p r e s c r i b i n g drugs (for e x a m p l e , wa te r pi l ls) fo r your b l o o d p r e s s u r e or hear t c o n -d i t i o n ? 7 . Do y o u know of any o t h e r r e a s o n why y o u s h o u l d not do phys ica l act iv i ty? If you answered YES to one or more questions Talk with your doctor by phone or in person BEFORE you start becoming much more physicaiy active or BEFORE you have a fitness appraisal. Tell your doctor about the PAR-Q and which questions you ara»ered YES. • You maybe able to do any activity you want—as tongas you start slowly and build up gradually. Or, you may need to restrict your activities to those which are sale for you. Talk *ith your doctor about the kinds of activities you wish to participate in and follow his/her advice. • Find out which community programs are sate and helpfd for you, / NO to all questions f you answered HO honestly to a| PAR-Q questions, you can be reasonably sure that you can: • start becoming much more physically active - begin slowly and build up graduaSy. This is ihe safest and easiest way to go. • take part in a fitness appraisal - this is an excellent way to determine your basic fitness so that you can plan the best way tor you to live actively. It is also highly recommended that you have your blood pressure evaluated. If your reading is over 144/94, talk with your doctor before you start becoming much more physically active. DELAY BECOMING MUCH MORE ACTIVE: * it you are not feeling well because of a temporary Illness such as a cold or a fever—wait until you feel better; or * if you are or may be pregnant - talk to your doctor before you start becoming more active. PLEASE NOTE: If your health changes so that you then answer YES to any of the above questions, tell your fitness or health professional. Ask whether you shouki change your physical activity plan. Informal Use of the BW-Q: The Canadian Sodety lor Exercise Ph'/siobgj Health Canada, and then- agents assume oo liability far persons mho undertake physical activity, and if in doubt after completing this questionnaire, consult 'your doctor prior to physical activity N o c h a n g e s p e r m i t t e d . Y o u a r e e n c o u r a g e d t o p h o t o c o p y t h e P A R - Q but o n l y i f y o u u s e t h e e n t i r e f o r m . MOTE: If the PAR-Q is being given to a person before he or she partidpates in a physical activity program or a fitness appraisal, this section may be used for legal or administrative prxposes. "I have read, understood and completed this questionnaire. Any questions I had were answered to my full satisfaction." SiaBTUKCf PSRENt crGUflflQUfS |fcr psri»3p*>*5 undfr ihe affs cf fnafcrity) Note: This physical activity clearance ts val id for a maximum of 12 months f rom the date it is completed and becomes invalid if your condit ion changes so that you would answer YES to any of the seven quest ions. 80 Who is conducting this study: Dr. Janice Eng and Adrienne H o i are conducting this study in conjunction with the University of British Columbia, School of Rehabilitation Sciences. The study wi l l take place at the G F Strong Rehab Centre in Vancouver, British Columbia. Funding for this study has been provided by the British Columbia Neurotrauma Fund. Background: Heart disease is currently the leading cause o f death in individuals with spinal cord injury. One o f the most significant risk factors for heart disease is low fitness levels, a condition that is common among those with spinal cord injury. Fitness testing is important to help identify heart disease risk, but standard fitness tests (for example, measuring oxygen intake during arm cycling exercise) require expensive equipment and a physician to be present. We hope to develop a fitness test that can be completed with minimal equipment and that accurately predicts fitness levels. Such a test would be beneficial to both individuals with spinal cord injury and clinicians. What is the purpose of this study? The purpose of this study is to evaluate a simple arm crank exercise test in individuals with spinal cord injury. This fitness test w i l l be compared to a standard fitness test to determine how accurate it is. Who can participate in this study? If you meet the following criteria you are eligible to participate in this study: • Had a traumatic spinal cord injury (at least 6 months ago) • Are between the ages of 18-50 • Use a manual wheelchair for your daily activities • Able to push an arm crank cycle In order to ensure that you w i l l be able to understand and follow all of the instructions that w i l l be given during the research study, you w i l l initially be given the Cognitive Capacity Screening Evaluation. Y o u w i l l also be asked several general questions about your current health status to help to decide whether you are safe to participate in this study. Who should not participate in this study? If you have any of the following conditions you are not eligible to participate in this study: • Have a known history o f cardiovascular disease (irregular heart beat, chest pains, etc) • Have respiratory disease, uncontrolled high blood pressure or injuries to muscles, bones, ligaments, tendons or joints • Have increased pain with arm activities • Have a brain injury which stops you from understanding the instructions that w i l l be given during the research study What does the study involve? This study wi l l take place at the Rehab Research Laboratory at G F Strong Rehab Centre. Sixty persons with spinal cord injury w i l l be recruited for this study. 82 Medical Information: If you received treatment for your spinal cord injury at G F Strong Rehab Centre (the provincial spinal cord injury rehabilitation centre) your medical records w i l l be looked at, and the following information taken from them: lesion level, date of injury, and type of injury. If you did not receive treatment at G F Strong Rehab Centre, a form w i l l be sent to your family physician to obtain that information. To determine some more information about your spinal cord injury, you w i l l be asked to try to move different parts o f your body, and well , using a safety pin and cotton-tip swab, different areas of skin on your body wi l l be lightly touched, and you w i l l be asked to report any sensation. Time Commitment for the Study: Y o u w i l l attend three testing sessions over a one month period. Each w i l l take approximately one hour. During one session, you wi l l have a cardiovascular stress test, and during the other two sessions, you wi l l complete the arm crank cycle test. In total, three hours of your time is required for the testing. Cardiovascular Stress Test: The stress test, which also measures your cardiovascular function, wi l l be a test performed on an arm crank cycle in the presence of a physician and kinesiologist. Y o u w i l l begin to cycle with your arms at a very light intensity, and as the test progresses, the intensity w i l l gradually increase until your arms are tired. The intensity refers to how challenging the arm cycling wi l l be; it w i l l be very easy when you begin and gradually become more difficult. Y o u w i l l have 12 electrodes attached to your chest (they stick to your skin similar to a band-aid, and are painless when on your skin) to measure how well your heart and lungs are handling the exercise. Y o u w i l l also be fitted with a face mask to measure the amount of oxygen that you are breathing in. Before you start wheeling, and at the end of the stress test, your finger w i l l be pricked, and one drop of blood taken to measure your lactate levels (a chemical that builds up in your blood during exercise). The test w i l l be stopped i f any abnormal signals arise from the electrodes monitoring your heart, or i f you feel chest discomfort, i f you feel dizzy or lightheaded, or i f your blood pressure gets too high. A r m Cycle Testing: Y o u w i l l be asked to complete an exercise test using an arm crank cycle. The cycling w i l l begin at a very low intensity, and for two minutes, the intensity w i l l gradually increase until your arms are working somewhat-hard. Y o u w i l l continue to arm cycle at this somewhat-hard intensity for 5 minutes. During the arm cycling, you w i l l wear a heart rate monitor, and w i l l be fitted with a face mask to measure the amount o f oxygen that you are breathing in. Before you start arm cycling_and at the end of the 7 minutes, your finger w i l l be pricked, and one drop of blood taken to measure your lactate levels. A s well , you wi l l be asked to describe any sporting activities that you are currently involved with. What are the possible harms and side effects of participating? There is a slight chance that you may feel tired or experience some muscle soreness after the testing sessions. During and immediate following the cardiovascular stress test, you may experience some discomfort (i.e. dry mouth, dizziness from breathing too heavily, muscle soreness). These symptoms can be minimized by drinking 2 cups of water prior to testing, 83 and deep breathing and stretching following the test. In addition, there is a slight chance that the electrodes used to monitor your heart and lung function during the stress test may cause skin irritation. During any activities which involve exercise, there is a low risk that you may experience a cardiac event. Some o f the questions you wi l l be asked before the study begins wi l l determine i f you are more likely to experience a cardiac event, and i f you are, you w i l l not be able to participate in the study. The stress testing wi l l be done with a physician present. What are the benefits of participating in this study? There are no direct benefits to you, other than determining the current status of your cardiovascular fitness. If you withdraw your consent to participate: • Your participation in this study is entirely voluntary. Y o u may withdraw at any time. I f you decide to enter the study and to withdraw at any time in the future, there w i l l be no penalty or loss of benefits to which you are otherwise entitled, and your future medical care w i l l not be affected. • The study investigators may decide to discontinue the study at any time, or withdraw you from the study at any time, i f they feel that it is in your best interest. • If you choose to enter the study and then decide to withdraw at a later time, all data collected about you during your enrollment in the study w i l l be retained for analysis. B y law, this data cannot be destroyed. If something goes wrong: Y o u do not waive any of your legal rights to compensation by signing this consent form. In case of a serious medical event, please report to an emergency room and inform them that you are participating in a research study and the following person can then be contacted for further information: Adrienne Hoi at telephone number 604-(number w i l l be activatedby Telus). After the study is completed: Once the study is completed and all o f the data is analyzed, you w i l l receive a short summary of the status of your cardiovascular fitness. Your cost to participate: Y o u may incur personal travel expenses by participating in this study. In order to defray the costs of transportation and to compensate you for your time, you wi l l receive $50 after each session, for a total of $150. Confidentiality: Your confidentiality w i l l be respected. N o information that discloses your identity w i l l be released or published without your specific consent to the disclosure. However, research records and medical records identifying you may be inspected in the presence of the Investigator or his or her designate by representatives of Health Canada, and the U B C Research Ethics Board for the purpose o f monitoring the research. However, no records which identify you by name or initials w i l l be allowed to leave the Investigators' offices. 84 Contact Information: If you have any questions or desire further information with respect to this study or experience any harmful side effects during participation, you can contact Dr. Janice Eng or one of her associates " . . . I f you have any concerns about your rights as a research participant and/or your experiences while participating in this study, contact the 'Research Subject Information Line in the University of British Columbia Office Research Services' 85 Consent to Participate: This is not a contract and I understand that I do not give up any legal rights by signing it. B y signing the Form I am indicating that: • I have read and understood the subject information and consent form. • I have had sufficient time to consider the information provided and to ask for advice i f necessary. • I have had the opportunity to ask questions and have had satisfactory responses to my questions. • I understand that all the information collected wi l l be kept confidential and that the results w i l l only be used for scientific objectives. • I understand that my participation in this study is voluntary and I am completely free to refuse to participate or to withdraw from this study at any time without changing in any way the quality of care that I receive. • I understand that I am not waiving any legal rights as a result of signing this consent form. • I have read this form and I freely consent to participate in this study. • I have been told that I w i l l receive a dated and signed copy of this form. Printed name of subject Subject signature Date Printed name of witness Witness signature Date Printed name of principal Signature of principal Date investigator/designated investigator/designated representative representative 86 APPENDIX E: Sample size calculation r Power 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 a,-=0.05 0.70 470 117 52 28 18 12 8 6 4 0.80 617 153 68 37 22 15 10 7 5 0.90 854 211 92 50 31 20 13 9 6 a2=0.05 0.70 616 153 67 37 15 10 7 5 0.80 783 194 85 46 GD > 18 12 9 6 0.90 1047 259 113 62 37 24 16 11 7 Adapted from Table 3.4.1 in Cohen (1988) 87 APPENDIX F: Cognitive Capacity Screening Evaluation Instructions: Check items answered correctly. Write incorrect or unusual answers in space provided. If necessary urge subject to complete task. Introduction to subject: "I would like to ask you a few questions. Some you will find very easy and others may be very hard. Just do your best." Questions Correct Incorrect / unusual answer 1. What day of the week is this? 2. What month? 3. What day of month? 4. What year? 5. What place is this? 6. Repeat the numbers 8 7 2 7. Say them backwards. 8. Repeat the numbers 6 3 7 1 9. Remember these numbers 6 9 4 Count 1 through 10 out loud, then repeat the numbers (6 9 4). If help needed use numbers 5 7 3 88 10. Remember these numbers 8 1 4 3. Count 1 through 10 out loud, then repeat the numbers (8 1 4 3). 11. Beginning with Sunday, say the days of the week backwards. 12. 9 + 3 is: 13. Add 6 (to the previous answer or "to 12") 14. Take away 5 ("from 18") Repeat these words after me and remember them. 1 will ask for them later: HAT, CAR, TREE, TWENTY-SIX 15. The opposite of fast is slow. The opposite of up is: 16. The opposite of large is: 17. The opposite of hard is: 18. An orange and a banana are both: Red and blue are both: 19. A penny and a dime are both: 20. What were those words I asked you to remember? (HAT) 21. (CAR) 89 22. (TREE) 23. (TWENTY-SIX) 24. Take away 7 from 100, then take away 7 from what is left and keep going: 100-7 is (93) 25. Minus 7 (86) 26. Minus 7 (79) 27. Minus 7 (72) 28. Minus 7 (65) 29. Minus 7 (58) 30. Minus 7 (51) TOTAL CORRECT 130 90 APPENDIX G: ASIA classification of spinal cord injury ASIA IMPAIRMENT SCALE • A = Complete: No motor or sensory function is preserved in the sacral segments S4-S5. • B = Incomplete: Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-S5, n c= Incomplete: Motor function is preserved below the neurological level, and more than half of key muscles below the neurological level have a muscle grade less than 3. = Incomplete: Motor function is preserved below the neurological level, and at least half of key muscles below the neurological level have a muscle grade of 3 or more. • D E = - Normal: motor and sensory function are nonnal CLINICAL SYNDROMES O Central Cord a Brown-Sequard • Anterior Cord o o Cotius Medullaris Cauda Equina S T A N D A R D N E U R O L O G I C A L C L A S S I F I C A T I O N O F S P I N A L C O R D I N J U R Y C2 G3 C4 CS c e C7 C8 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 L1 L2 L3 L4 L5 81 82 S3 84-5 TOTALS _ H (MAXIMUM) (60) M O T O R KEY MUSCLES C2 C3 C4 Elbow flexors C5 Wrist extensors C6 Elbow extensors C7 I I Finger flexors (distal phalanx of middle finger) C8 LIGHT PIN TOUCH PRICK R L R L Finger abductors (Ittte finger) 0 = total paralysis 1 = palpable or visible contraction 2 = active movement gravity etMrtBted 3 = active movement against gravity & - active movement, against some resistance 5 - active movement, against Mi resistance NT = not testable Hip flexors Knee extensors Ankle dorsiflexors Long toe extensors Ankle plantar flexors KEY SENSORY POINTS Voluntary anal contraction (Yes/No) T1 T2 T3 T4 TS TB T7 TB T9 T10 T11 T12 L1 L2 L3 L4 L5 S1 S2 S3 S4-5 • = (SO) MOTOR SCORE TOTALS (100.} (£5 0 = absent 1 = mpewsd 2 = normal NT =not testable Key S«iHtf}' Iritis (MAXIMUM) (SB) (EE) (BE) | | Any anal sensation (Yea/No) HPIN PRICK SCORE LIGHT TOUCH SCORE m (max: 112) (ITER: 112) NEUROLOGICAL R L LEVEL S E N S O R Y r n i l 1 TTw most r^syoW^ cgrrmnJ MOTOR | COMPLETE OR INCOMPLETE? bxxxnpfeto - Any sujucry orrVaotarSwc&an in S4-&S AStA IMPAIRMENT SCALE ZONE OF PARTIAL R L PRESERVATION! SENSORY H I cwMortBArarf ikvNMy MOTOR I IT*~n ThiBform may be copied freely but should not be altered without permission from Una American Spinal Injury Association. APPENDIX H: Physical Activity Scale for Individuals with Physical Disabilities Leisure Time Activity 1. During the past 7 days how often did you engage in stationary activities such as reading, watching T V , computer games, or doing handcrafts? a) never (go to question #2) b) seldom ( 1 - 2 days) c) sometimes (3 ~ 4 days) d) often (5 ~ 7 days) What were these activities? . On average, how many hours per day did you spend in these stationary activities'? a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours 2. During the past 7 days, how often did you walk, wheel, push outside your home other than specifically for exercise. For example, getting to work or class, walking the dog, shopping, or other errands? a) never (go to question #3) b) seldom (1 ~ 2 days) c) sometimes ( 3 - 4 days) d) often (5 - 7 days) On average, how many hours per day did you spend walking, wheeling or pushing outside your home? a) less than 1 hour b) 1 but less then 2 hours c) 2 to 4 hours d) more than 4 hours 3. During the past 7 days, how often did you engage in light sport or recreational activities such as bowling, golf with a cart, hunting or fishing, darts, billiards or pool, therapeutic exercise (physical or occupational therapy, stretching, use of a standing frame) or other similar activities? a) never (go to question #4) b) seldom ( 1 - 2 days) c) sometimes (3 - 4 days) d) often ( 5 - 7 days) What were these activities? 93 On average, how many hours per day did you spend in these light sport or recreational activities! a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours 4. During the past 7 days, how often did you engage in moderate sport and recreational activities such as double tennis, softball, golf without a cart, ballroom dancing, wheeling or pushing for pleasure or other similar activities? a) never (go to question #5) b) seldom ( 1 - 2 days) c) sometimes ( 3 - 4 days) d) often ( 5 - 7 days) What were these activities? • On average, how many hours per day did you spend in these moderate sport and recreational activities! a) less than 1 hour b) 1 but less than 2 hours c) 2~4hours d) more than 4 hours 5. During the past 7 days, how often did you engage in strenuous sport and recreational activities such as jogging, wheelchair racing (training), off-road pushing, swimming, aerobic dance, arm cranking, cycling (hand or leg), singles tennis, rugby, basketball, walking with crutches and braces, or other similar activities? a) never (go to question #6) b) seldom ( 1 - 2 days) c) sometimes ( 3 - 4 days) d) often (5 - 7 days) What were these activities? On average, how many hours per day did you spend in these strenuous sport or recreational activities? a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours 94 6. During the past 7 days, how often did you do any exercise specifically to increase muscle strength and endurance such as lifting weights, push-ups, pull-ups, dips, or wheelchair push-ups, etc? a) never (go to question #7) b) seldom (1 ~ 2 days) c) sometimes ( 3 - 4 days) d) often (5 - 7 days) What were these activities? • '. • On average, how many hours per day did you spend in these exercises to increase muscle strength and endurance"? a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours Household Activity 7. During the past 7 days, how often have you done any light housework, such as dusting, sweeping floors or washing dishes? a) never (go to question #8) b) seldom ( 1 - 2 days) c) sometimes ( 3 - 4 days) d) often (5 - 7 days) On average, how many hours per day did you spend doing light housework? a) less than 1 hour b) 1 but less than 2 hours c) 2~4hour s d) more than 4 hours 8. During the past 7 days, how often have you done any heavy housework or chores such as vacuuming, scrubbing floors, washing windows, or walls, etc? a) never (go to question #9) b) seldom ( 1 - 2 days) c) sometimes (3 ~ 4 days) d) often ( 5 - 7 days) 95 On average, how many hours per day did you spend doing heavy housework or chores'? a) less than 1 hour b) 1 but less than 2 hours c) 2 ~ 4 hours d) more than 4 hours 9. During the past 7 days, how often have you done home repairs like carpentry, painting, furniture refinishing, electrical work, etc? a) never (go to question #10) b) seldom ( 1 - 2 days) c) sometimes (3 - 4 days) d) often (5 - 7 days) On average, how many hours per day did you spend doing home repairs? a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours 10. During the past 7 days, how often have you done lawn work or yard care including mowing, leaf or snow removal, tree or bush trimming, or wood chopping, etc? a) never (go to question #11) b) seldom ( 1 - 2 days) c) sometimes ( 3 - 4 days) d) often ( 5 - 7 days) On average, how many hours per day did you spend doing lawn work? a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours 11. During the past 7 days, how often have you outdoor gardening? a) never (go to question #12) b) seldom (1 - 2 days) c) sometimes ( 3 - 4 days) d) often ( 5 - 7 days) 96 On average, how many hours per day did you spend doing outdoor gardening? a) less than 1 hour b) 1 but less than 2 hours . c) 2 - 4 hours d) more than 4 hours 12. During the past 7 days, how often have did you care for another person, such as children, a dependent spouse, or another adult? a) never (go to question #13) b) seldom (1 ~ 2 days) c) sometimes (3 ~ 4 days) d) often ( 5 - 7 days) On average, how many hours per day did you spend caring for another person? a) less than 1 hour b) 1 but less than 2 hours c) 2 - 4 hours d) more than 4 hours Work-Related Activity 13. During the past 7 days, how often have did you work for pay or as a volunteer? Exclude work that mainly involved sitting with slight arm movement such as light office work, computer work, light assembly line work, driving bus or van, etc.) a) never (go to E N D ) b) seldom ( 1 - 2 days) c) sometimes ( 3 - 4 days) d) often (5 - 7 days) On average, how many hours per day did you spend working for pay or as a volunteer? a) less than 1 hour b) 1 but less than 4 hours c) 5 but less than 8 hours d) 8 hours or more 97 APPENDIX I: Strength testing - positioning and data collection Elbow Flexors: Shoulder 0° abduction, elbow 90° flexion (R): ' 1) ~ ] ' y y - • •-:• 0 2) ; 2)_ 3) _ . . ;3). Elbow Extensors: Shoulder 0° abduction, 45° flexion, elbow 90° flexion (R): 1) <L):1) 2) 2) 3) _ ._ 3) Shoulder Flexors: Shoulder 0° abduction, elbow 0° extension (R): 1) ( L ) : l ) 2) 2 ) _ 3) 3 ) _ Shoulder Extensors: Shoulder 0° abduction, elbow 0° extension (R): 1) ( L ) : 1) 2) 2 ) _ 3) 3 ) _ Wrist Flexors: Forearm on table, elbow extended, wrist neutral, palm up (R): 1) (L) : 1) 2) 2 ) : 3) 3 ) : Wrist Extensors: Forearm on table, elbow extended, wrist neutral, palm down (R): 1) ( L ) : l ) 2) 2) 3) 3) Appendix J: Borg's Rating of Perceived Exertion Scale (Borg 1970) 6 7 very, very light 8 9 very light 10 11 fairly light 12 13 moderately hard 14 15 hard 16 17 very hard 18 19 very, very hard 20 APPENDIX K: Blood lactate measurement protocol (http://www.lactatepro.com.au/using.asp) Peel a Test Strip packet to the line indicated and insert it into the Strip Inlet of the Test Meter as shown. A beep w i l l be heard, and "88.8"will appear in the display. Disinfect the finger you w i l l draw blood from by using a gauze and alcohol and dry it thoroughly. Use the lancing device on your finger and press the finger until a drop of blood forms. Use a new lancet every time. Apply pressure to the surrounding site to obtain a drop of blood. The required amount of blood is 5mmol/l. Using the original foil packet, grasp the use Test Strip as shown above. In 60 seconds, the test result of blood lactate level w i l l appear in the display. The blood is aspirated automatically. Apply pressure to the surrounding site again to obtain a drop of blood. Especially, sweat affects test result. Wipe the blood with a gauze and alcohol since the first drop of blood contains sweat. Note: Examination gloves were worn during the protocol. Used lancets were disposed of into in a bio-hazardous materials container. 100 APPENDIX L: Electrode placement for ECG leads Electrode Placement for Limb and Augmented Leadsfl, II, II, AVF, AVR, AVL) R L : Right Leg- (Ground wire) put on the right acromion process R A : Right A r m - put just inferior the right clavicle L I , : Left Leg- put just superior to the left A S I A L A : Left A r m - put just inferior to the left clavicle Electrode Placement for Precordial Leads (VI, V2, V3, V4, V5, ¥6) VI 4 intercostal space, right of sternum V2 4 t h intercostal space, left o f sternum V3 midway between V 2 and V 4 V4 5 t h intercostal space, in the midclavicular line V5 same level as V 4 , at anterior axillary line (between V 4 and V 6 ) V6 in 5 t h intercostal space, in the midaxillary line ECG Electrode Skin Preparation 1. Shave the skin so it is free of hair. 2. Rub the spot with alcohol until it is red. APPENDIX M: V02peak Protocol Equipment calibration: The Cosmed K 4 b 2 was used to for metabolic measurement. The equipment consists o f a soft mask to sample exhaled air, a sensor system to measure ventilation, and oxygen and carbon dioxide analyzers. Respiratory flow was measured by a turbine fixed to the face mask, and expired gas concentrations were measured using a polarographic electrode for the oxygen fraction and an infrared electrode for the carbon dioxide fraction. The Cosmed K 4 b 2 system was calibrated before each test according to the manufacturer's recommended procedures (operator's manual of K 4 b 2 system). Calibrations included a gas calibration using gas of a known concentration (16% oxygen, 5% carbon dioxide), a delay calibration to determine the time delay between expiration and inspiration, and a turbine calibration using a known volume o f air. Positioning: A l l subjects remained seated in their wheelchair (brakes on) for the VC>2peak test. Adjustments were made so that the centre o f the crank was level with their shoulder (in either the height of the ergometer, or the height o f the wheelchair). Subjects were positioned so that during the arm cycling their elbows did not reach full extension. Instructions: A l l subjects were given verbal instructions prior to beginning the test. First they were informed of a short (1-2 minute) warm-up period, where they were able to cycle against zero resistance to get used to the motion of the arm ergometer. Subjects were then told: "During the test, the resistance, or difficulty of the cycling w i l l start out pretty light. A t the end of each minute, it w i l l get a little bit harder: We want you to keep cycling at the same cadence (speed) for the whole test. Towards the end when it starts to get quite a bit harder, w e ' l l give you some encouragement to keep you cycling for as long as you can. If you feel any chest pain, lightheadedness, dizziness or feel sick to your stomach, please stop the test right away and tell us how you are feeling." Protocol: For subjects with paraplegia, the PO increased at lOW/min. For subjects with tetraplegia, PO increased at 5W/min. 102 V02max Test - data collection sheet Subject code: Height: Gender: Date of Birth: _ Age: Weight: Mask Size: S M L Protocol: Start: H R : Lactate: End: H R : Lactate: _ Peak W R : B P : B P : R P E : Recovery: 1 min 2 min 3 min 4 min 5 min BP HR 103 APPENDIX N: Psychometric properties of outcome measures Outcome Measure Reliability Validity American Spinal Injury Association (ASIA) Impairment Scale Motor Score: Intra-rater reliability, intraclass correlation coefficient (ICC)=0.99, inter-rater reliability ICC-0.98 Pin Prick Score: Intra-rater reliability ICC=0.98, inter-rater reliability ICC=0.96 Light Touch Score: Intra-rater reliability ICC=0.99, inter-rater reliability ICC=0.96 Impairment Scale: Intra-rater reliability Kappa=0.84, inter-rater reliability Kappa=0.72 (Cohen and Bartko 1994) Motor Score: Criterion validity with cumulative motor score, r=0.988 (El Masry et al. 1996) Blood Lactate Inter-rater reliability: The correlation between two Lactate Pro analysers on the same sample was r=0.99 (Pyne et al. 2000) Concurrent Validity: Correlations between lactate measurements using the Lactate Pro and the A B L 700 Series Acid-Base analyser, the YSI2300 Stat lactate analyser and the Accusport Lactate Meter were r=0.98, r=0.99 and r=0.97, respectively (Pyne et al. 2000) Cognitive Capacity Screening Evaluation (CCSE) Reliability results not found in the literature. Concurrent Validity: Agreement of C C S E scores indicating the presence of a cognitive deficit (<20) with complete neurological evaluation in: O f 59 cases, 24 true-positive, 2 false-negative, 18 true-negative, 9 false-negative (Kaufman et al. 1979) 104 Isometric : strength -hand held dynamometer Intra-rater reliability: Test-retest Pearson product-moment correlations (in individuals with various orthopaedic or neuromuscular diagnoses): 0.69 <r <0.90 (p ^).05) (Wadsworth et al. 1987) Inter-rater reliability: Pearson product-moment correlation between raters (in individuals with various orthopaedic or neuromuscular diagnoses including SCI): 0.84 <r <0.94 (p^ .OOl ) (Bohannon and Andrews 1987) Concurrent Validity: Correlations between strength scores obtained by handheld dynamometry and isokinetic dynamometry (in individuals with SCI): 0.75 <r <0.96 (p^ .OOl ) (Noreau and Vachon 1998) Correlations between manual muscle testing and handheld dynamometry (in individuals with SCI): 0.59 <r <0.94 (p 50.001) (Schwartz et al. 1992) Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) Internal consistency: Cronbach's a = 0.37-0.65 (in individuals with various orthopaedic and neuromuscular diagnoses including SCI) (Washburn et al. 2002) Construct validity: Correlations between each survey item & total P A S I P D score were all =f).20 (0.20-0.67) and significant Factor analysis revealed 5 factors (in individuals with various orthopaedic and neuromuscular diagnoses including SCI) (Washburn et al. 2002) 105 APPENDIX O: Selected results (paraplegia/tetraplegia) - with subjects presented as two groups Subject characteristics Variable Subjects with Paraplegia (n=13) Subjects with Tetraplegia <n=17) Mean(SD) Range Mean (SD) Range S e x ( M / F ) , N 8/5 17/0 Age (years) 34.3 (10.2) 19-49 37.9(8.5) 22-49 Time since injury (years) 6.0(6.5) 1-24 16.5 (9.5) 1-34 A S I A Grade ( A / B / C / D ) , N 10/2/0/1 12/5/0/0 A S I A Motor Score (0-100) 57.4 (9.8) 50-75 28.8 (7.6) 19-48 P A S I P D score 18.6(10.8) 4.8-38.7 14.9 (8.9) 1.0-30.5 Wheeled mobility category 0/0/2/10/1 2/1/9/5/0 (1/3/4/5/6), N Values during the VC^peak test Subjects with Paraplegia (n=13) Subjects with Tetraplegia (n=17) Mean (SD) Range Mean (SD) Range Peak work rate (W) 91.5(31.3) 50-160 36.2(14.4) 20-80 Peak H R (beats/min) 154.6(22.3) 109-183 109.6 (14.0) 75-132 Percent H R maximum 1 83.0 (9.5) 63.0-97.3 60.1 (6.8) 43.6-71.7 VChpeak (mL/kg/min) 24.7 (9.0) 10.8-38.1 13.9 (3.4) 6.5-19.8 V02peak (L/min) 1.70(0.56) 0.97-2.81 1.05 (0.23) 0.74-1.62 Blood lactate (mmol/L) 8.9 (2.5) 5.7-15.1 5.1 (1.8) 2.3-8.4 Based on 220-age prediction equation 2 Only 27 of 30 subjects had their blood lactate tested Steady state values during the SSSAET Variables Subjects with Paraplegia Subjects with Tetraplegia (n =13) (n= =17) Mean (SD) Range Mean (SD) Range S S S A E T work rate (W) 43.1 (12.0) 20-60 16.2 (9.3) 10-40 H R (beats/min) 117.9(16.8) 88-142 91.8(17.0) 61-124 Percent H R maximum 1 63.4 (7.5) 51.5-75.7 50.3 (8.3) 35.7-65.2 V 0 2 (mL/kg/min) 15.9 (3.9) 10.2-22.9 10.9 (2.9) 6.3-19.1 V 0 2 (L/min) 1.11 (0.26) 0.65-1.61 0.83 (0.23) 0.55-1.57 Percent VC»2peak 67.9(12.5) 51.0-94.3 79.6(11.2) 62.4-97.8 Blood lactate (mmol/L) 2 3.5(1.38) 1.0-6.0 2.6(1.2) 1.2-4.9 Based on 220-age prediction equation 2 Only 28 of 30 subjects had their blood lactate tested 107 Scatterplots and values of test-retest reliability of HR 130 110 50 70 90 110 Test 1 HR (beats/min) 130 Scatter-plot comparing H R during S S S A E T test 1 and test 2 for subjects with tetraplegia (n=T2) ICC 2 >i=0.82 SEM=7.89 95% CI=0.48-0.94 80 100 120 Test 1 HR (beats/min) 140 Scatter-plot comparing H R during S S S A E T test 1 and test 2 for subjects with paraplegia (n=8) ICC 2 >i=0.82 SEM=6.58 95% CI=0.34-0.96 108 Scatterplots and values of test-retest reliability of V0 2 130 - i c 1 110 -<5 0 X C M </> 70 -<D r -50 -50 70 90 110 Testl HR (beats/min) 130 Scatter-plot comparing VO2 during S S S A E T test 1 and test 2 for subjects with tetraplegia (n=12) ICC 2 >i=0.70 SEM=1.78 95% CI=0.25-0.90 - £ 140 ro a> 120 si 80 100 120 Testl HR (beats/min) 140 Scatter-plot comparing VO2 during S S S A E T test 1 and test 2 for subjects with paraplegia (n=8) ICC 2 >i=0.80 SEM=1.52 95% CI=0.29-0.96 109 Scatterplots and correlations between SSSAET PO and V02peak 10 20 30 SSSAET PO (W) 40 50 Scatter-plot comparing P O during the S S S A E T and V02peak for subjects with tetraplegia (n=l 7) r=0.40 (p=0.112) 20 40 60 SSSAET PO (W) Scatter-plot comparing P O during the S S S A E T and V02peak for subjects with paraplegia (n=13) r=0.54 (p=0.066) 80 110 Scatterplots and correlations between SSSAET V0 2 and V02peak 0 5 1 0 1 5 2 0 SSSAET V02 (mL/kg/min) 2 5 Scatter-plot comparing V 0 2 during the S S S A E T and V0 2 peak for subjects with tetraplegia (n=17) r=0.852 (p<0.001) 40 c E o> E, ro o o. CM o > 30 20 10 © © © © @ © © 10 15 20 SSSAET V02 (rnUkg/min) 25 Scatter-plot comparing V 0 2 during the S S S A E T and V0 2 peak for subjects with paraplegia (n=13) r=0.933 (pO.OOl) 111 Scatterplots and correlations between SSSAET HR and V02peak 50 70 90 110 130 SSSAET HR (beats/min) 150 Scatter-plot comparing H R during the S S S A E T and VC^peak for subjects with tetraplegia (n=17) •r=0.343 <p=0.178) 5 0 7 0 9 0 1 1 0 1 3 0 SSSAET HR (beats/min) 1 5 0 Scatter-plot comparing H R during the S S S A E T and V02peak for subjects with paraplegia (n=T3) r=0.446 (p=0.127) 112 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0092474/manifest

Comment

Related Items