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The implications of kinaesthetic training on coordination Gray, Charla Krystine 2000

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T H E I M P L I C A T I O N S O F K I N A E S T H E T I C T R A I N I N G O N C O O R D I N A T I O N by C H A R L A K R Y S T I N E G R A Y B . H . K . , The University of British Columbia, 1997 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 L M E N T O F 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 OF S C I E N C E in T H E F A C U L T Y OF G R A D U A T E S T U D I E S (Department of Neuroscience) We accept this thesis as conforming to the required standard 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 M a y 2000 © Charla Krystine Gray, 2000 in p resen t ing this thesis in partial fu l f i lment of the requ i rements for an advanced deg ree at the Univers i ty of Brit ish C o l u m b i a , I agree that the Library shall make it f reely avai lable fo r re ference and study. I further agree that pe rm i s s i on fo r ex tens ive c o p y i n g o f this thes is fo r scholar ly pu rposes may b e granted by the h e a d of my depa r tmen t o r by his o r her representat ives. It is u n d e r s t o o d that c o p y i n g o r pub l i c a t i on of this thesis for f inancia l gain shal l no t be a l l o w e d w i t h o u t my wr i t t en pe rm i s s i on . Depa r tmen t of The Univers i ty of Brit ish C o l u m b i a Vancouve r , C a n a d a Date cWu, 5 , c^OOO . DE-6 (2/88) Abstract Kinaesthetic training is used in many rehabilitation settings to improve kinaesthetic awareness of the injured limb. While this type of training improves one's sense of body awareness, the functional implications of kinaesthetic training remain unknown. The primary goal of this experiment was to explore the effects of kinaesthetic training on one's coordination. The coordination and kinaesthetic awareness of three groups, a control group, an actively trained group and a passively trained group, were tested before and after kinaesthetic training. Each group consisted of seven healthy female volunteers. Only the two training groups participated in four days of kinaesthetic training. In addition the coordination and kinaesthesis of the training groups was re-tested one and three weeks after the post-training test to measure the retention of the post-training performance. The results indicate that there was no improvement on the coordination task on the post-training test. In contrast, the results indicate that active kinaesthetic training improves kinaesthetic awareness. However, the improvement in kinaesthetic awareness was not retained on the two retention tests. The findings from this study imply that improving one's sense of body awareness does not simultaneously improve their coordination. Possible explanations for the lack of improvement include various aspects of the training protocol (intensity and duration), the speed of movement and the type of coordination task used in this experiment. In addition, the findings suggest that the mechanisms underlying the improvement in kinaesthetic acuity are temporary and transient. i i Table of Contents Abstract i i List of Tables v List of Figures v i i i List of Correlation Matrices ix Chapter I: Overview 1 Introduction 1 Summary of Literature Review 3 Literature Review 5 Contributions to Kinaesthesis 5 Joint Afferents 5 Skin Afferents 7 Muscle Afferents 10 Individual Levels of Proprioceptive Awareness 15 Active versus Passive Kinaesthetic Sense 18 Training Kinaesthesia 20 Coordination 21 Stages of Motor Learning 24 A Relationship between Kinaesthesis and Coordination 25 Bilateral Transfer 27 Summary of Hypotheses 30 Chapter II: Methodology 32 Subjects 32 Procedure 32 Hardware 34 Spike2 35 C E D 1401 36 Potentiometer 36 Attenuator 36 Current Switch 37 Calibration 37 Electromyography ( E M G ) 38 Data Collection Protocols 38 Velocity of Movement Training 38 Coordination Testing Protocol 39 Kinaesthetic Testing Protocol 40 Active Kinaesthetic Training Protocol 41 Passive Kinaesthetic Training Protocol 42 Recording and Collecting Data 43 Coordination Testing Data 43 Kinaesthetic Testing Data 44 Kinaesthetic Training Data 44 Moving and Converting Data 45 Coordination 45 Kinaesthetic Testing and Training 45 Overall Procedure 45 Statistical Analysis 46 Design 47 Analysis of Hypotheses 47 Chapter III: Results 49 Group comparisons across the two days of testing 49 Analysis of coordination performance 50 Analysis of kinaesthetic performance 52 Changes across the four days of training 54 Retention 56 Retention of coordination performance 57 Retention of kinaesthetic performance 58 Type I Error 61 Chapter IV: Discussion and Conclusions 62 Subject Allocation 62 Velocity of Movement 62 Changes in performance on the coordination task 63 Changes in performance on the kinaesthetic task 65 Changes in performance of the trained and untrained limb 67 Coordination Theories 67 Limb effect 68 Day effect 68 Sources of Error 66 Group comparisons across the four days of training 69 Changes at the receptor level as a result of training 70 Retention 70 Conclusions 71 Sources of Error 72 Future considerations 73 References 75 Appendix A : Tables 80 Appendix B : Figures 99 Appendix C: Correlation Matrices 101 iv Lis t of Tables Table l a A N O V A results for the |CE| analysis of coordination 80 l b Mean performance values for each group for the |CE| analysis of coordination 80 l c Mean performance values for each limb for the |CE| analysis of coordination 80 Id Mean performance values for each day for the |CE| analysis of coordination 80 le Mean performance values for the group*limb interaction for the |CE| analysis of coordination 81 I f Mean performance values and standard deviations for the group*day interaction for the |CE| analysis of coordination 81 l g Mean performance values for the limb*day interaction for the |CE| analysis of coordination 81 l h Mean performance values for the group*limb*day interaction for the |CE| analysis of coordination 82 2a A N O V A results for the V E analysis of coordination 82 2b Mean performance values for each group for the V E analysis of coordination 82 2c Mean performance values for each limb for the V E analysis of coordination 82 2d Mean performance values for each day for the V E analysis of coordination 83 2e Mean performance values for the group*limb interaction for the V E analysis of coordination 83 2f Mean performance values and standard deviations for the group*day interaction for the V E analysis of coordination 83 2g Mean performance values for the limb*day interaction for the V E analysis of coordination 83 2h Mean performance values for the group*limb*day interaction for the V E analysis of coordination 84 3a A N O V A results for the |CE| analysis of kinaesthesis 84 3b Mean performance values for each group for the |CE| analysis of kinaesthesis 84 3c Mean performance values for each limb for the |CE| analysis of kinaesthesis 84 3d Mean performance values for each day for the |CE| analysis of kinaesthesis 85 3e Mean performance values for the group*limb interaction for the |CE| analysis of kinaesthesis 85 3f Mean performance values and standard deviations for the group*day interaction for the |CE| analysis of kinaesthesis 85 V 3g Mean performance values for the limb*day interaction for the |CE| analysis of kinaesthesis 85 3h Mean performance values for the group*limb*day interaction for the |CE| analysis of kinaesthesis 86 4a A N O V A results for the V E analysis of kinaesthesis 86 4b Mean performance values for each group for the V E analysis of kinaesthesis 86 4c Mean performance values for each limb for the V E analysis of kinaesthesis 86 4d Mean performance values for each day for the V E analysis of kinaesthesis 87 4e Mean performance values for the group*limb interaction for the V E analysis of kinaesthesis 87 4f Mean performance values and standard deviations for the group*day interaction for the V E analysis of kinaesthesis 87 4g Mean performance values for the limb*day interaction for the V E analysis of kinaesthesis 87 4h Mean performance values for the group*limb*day interaction for the V E analysis of kinaesthesis 88 5a A N O V A results for the |CE| analysis of training 88 5b Group means for the |CE analysis of training 88 5c Day means for the CE | analysis of training 88 5d Mean values for the day* group interaction for the |CE| analysis of training 89 6a A N O V A results for the V E analysis of training 89 6b Group means for the V E analysis of training 89 6c Day means for the V E analysis of training 89 6d Mean values for the day* group interaction for the V E analysis of training 90 7a A N O V A results for the |CE| analysis of the retention of coordination 90 7b Mean performance values for each group for the |CE| analysis of the retention of coordination 90 7c Mean performance values for each limb for the |CE| analysis of the retention of coordination 90 7d Mean performance values for each day for the |CE| analysis of the retention of coordination 91 7e Mean performance values for the group*limb interaction for the |CE| analysis of the retention of coordination 91 7f Mean performance values and standard deviations for the group*day interaction for the |CE| analysis of the retention of coordination 91 7g Mean performance values for the limb*day interaction for the |CE| analysis of the retention of coordination 91 7h Mean performance values for the group*limb*day interaction for the |CE| analysis of the retention of coordination 92 8a A N O V A results for the V E analysis of the retention of coordination 92 vi 8b Mean performance values for each group for the V E analysis of the retention of coordination ' 92 8c Mean performance values for each limb for the V E analysis of the retention of coordination 92 8d Mean performance values for each day for the V E analysis of the retention of coordination 93 8e Mean performance values for the group*limb interaction for the V E analysis of the retention of coordination 93 8f Mean performance values and standard deviations for the group*day interaction for the V E analysis of the retention of coordination 93 8g Mean performance values for the limb*day interaction for the V E analysis of the retention of coordination 93 8h Mean performance values for the group*limb*day interaction for the V E analysis of the retention of coordination 94 9a A N O V A results for the |CEJ analysis of the retention of kinaesthesis 94 9b Mean performance values for each group for the |CE| analysis of the retention of kinaesthesis 94 9c Mean performance values for each limb for the |CE| analysis of the retention of kinaesthesis 94 9d Mean performance values for each day for the |CE| analysis of the retention of kinaesthesis 95 9e Mean performance values for the group*limb interaction for the |CE| analysis of the retention of kinaesthesis 95 9f Mean performance values and standard deviations for the group*day interaction for the |CE| analysis of the retention of kinaesthesis 95 9g Mean performance values for the limb*day interaction for the |CE| analysis of the retention of kinaesthesis 95 9h Mean performance values for the group*limb*day interaction for the |CE| analysis of the retention of kinaesthesis 96 10a A N O V A results for the V E analysis of the retention of kinaesthesis 96 10b Mean performance values for each group for the V E analysis of of the retention of kinaesthesis 96 10c Mean performance values for each limb for the V E analysis of the retention of kinaesthesis 96 lOd Mean performance values for each day for the V E analysis of the retention of kinaesthesis 97 lOe Mean performance values for the group*limb interaction for the V E analysis of the retention of kinaesthesis 97 lOf Mean performance values and standard deviations for the group*day interaction for the V E analysis of the retention of kinaesthesis 97 10g Mean performance values for the limb*day interaction for the V E analysis of the retention of kinaesthesis 97 lOh Mean performance values for the group*limb*day interaction for the V E analysis of the retention of kinaesthesis 98 v i i Figure List of Figures 1: Overhead view of subj ect position 99 2: Overhead view of coordination task 99 3: Example of a movement followed by correction 100 4: |CE| analysis of the day*group interaction for coordination 50 5: V E analysis of the day*group interaction for coordination 51 6: |CE| analysis of the day*group interaction for kinaesthesis 53 7: V E analysis of the day*group interaction for kinaesthesis 54 8: |CE| analysis of the day* group interaction for training 55 9: V E analysis of the day*group interaction for training 56 10: |CE| analysis of the day*group interaction for the retention of coordination 58 11: V E analysis of the day* group interaction for the retention of coordination 59 12: I C E ! analysis of the day*group interaction for the retention of kinaesthesis 60 13: V E analysis of the day*group interaction for the retention of kinaesthesis 61 v i i i List of Correlation Matrices Matrix 1 Correlation matrix for |CE | analysis 2 Correlation matrix for V E analysis Chapter I Introduction Proprioception and kinaesthesis are one's sense of body awareness including sensations of joint position and joint motion. Our sense of body awareness allows us to know the position of our limbs in relation to our body in the absence o f vision and is provided by afferent information from joint, skin and muscle receptors. Several authors define movement position sense as kinaesthesis and static position sense as proprioception (Grigg 1994). Despite the definitions of these two terms they are often used interchangeably and for the remainder of this paper no distinction is made between the two terms. While many experiments focus on the physiology of kinaesthesis, current experiments explore the role of kinaesthesis in motor control and rehabilitation. Several papers suggest that proprioceptive training reduces proprioceptive deficits, increases postural control, reduces the potential for re-injury and decreases functional instabilities (Hoffman and Payne 1995 and Lephart et al 1997). Although these papers allude to the benefits of proprioceptive training, they fail to support the proposed benefits with experimental evidence. Currently only two studies provide results indicating that subjects improve their proprioceptive acuity after kinaesthetic training (Laszlo and Bairstow 1983 and Fry-Welch 1998). Despite improving kinaesthetic awareness, these experiments also fail to show the functional importance of training one's sense of body awareness; the training statistically improves one's kinaesthesis but the clinical significance of this improvement is not demonstrated. Does kinaesthetic training simultaneously improve neuromuscular function, or coordination? Kinaesthetic training 1 remains in its infancy as the protocol of this training and both the functional and clinical implications of this training remain unanswered. The role of proprioception has been implicated in coordination (Schmidt 1988, Kottke et al 1978, Gordon et al 1995, Sainburg et al 1993 and Cordo 1990). Demonstrating an improvement in coordination after kinaesthetic training would provide many benefits to rehabilitation and sports participation. For example, kinaesthetic training could be used to improve motor control after sustaining an injury. This type o f training could also be used in a number of sports programs to improve neuromuscular control and athletic performance. Despite the potential benefits of kinaesthetic training the link between training and functional improvement remains experimentally unexplored. The primary purpose of this research is to explore the functional implications of kinaesthetic training. The aim of the study is to show an improvement in coordination after training one's sense of body awareness. In addition, this study is designed to outline an additional method of training one's kinaesthetic sense. The results from this experiment can be implemented into rehabilitation programs in hospitals, clinics and sports training programs. 2 Summary of literature review Proprioception is our sense of body awareness in the absence of vision including the awareness of our limbs in relation to our body and in relation to each other. Proprioception is composed of both sensations of joint position and sensations of joint motion, often termed kinaesthesis (Barrack et al 1984). Both proprioception and kinaesthesis are provided by afferent information from joint, skin, and muscle receptors. While joint replacement experiments provide support against a role for joint afferent information in kinaesthesis (Grigg et al 1973), additional experiments provide conflicting results suggesting that joint afferents control joint stiffness thereby providing an important contribution to proprioception (Johannson et al 1991a and 1991b). Similarly, several studies provide support against a role for skin afferent information in position sense awareness (Horch et al 1975), while an equal number of experiments provide positive support for a role of skin afferents in kinaesthesis (Edin and Abbs 1991 and Moberg 1983). The role o f muscle afferent information is supported by experiments involving tendon vibration (Goodwin et al 1972a), tendon pulling (Matthews and Simmonds 1974) and muscle anesthesia (Clark et al 1985). While each source contributes to proprioception their degree of contribution remains unknown. Kinaesthesis is also referred to as our sixth inherent sense (Allegrucci et al 1995). Similar to our other senses, proprioceptive acuity varies between individuals. Individual differences are seen in age, gender, laterality and degree of sports participation. Measuring kinaesthesis is performed using many different tests. These tests are performed on various parts of the body, either actively or passively (Lloyd and Caldwell 3 1965 and Paillard and Brouchon 1968). There is currently no conclusive evidence on whether acuity is greater in active or passive testing. Despite the variety of tests and the varying levels of proprioception among individuals, several studies suggest that one's level of proprioception can be improved through training. The results from these studies indicate that proprioceptive performance among the experimental subjects shows greater improvement than the controls after training (Laszlo and Bairstow 1983 and Fry-Welch 1998). In addition, two studies show that one's kinaesthetic performance improves when afferent information from joint, skin and muscle receptors is enhanced (Perlau et al 1995 and Birmingham et al 1998). Coordination is "the behavior of two or more joints in relation to each other to produce skilled activity" (Schmidt 1988). Theories of coordination include the motor program theory and the schema theories, as well as the response-chaining hypothesis, the impulse-timing hypothesis and the equilibrium-point hypothesis. Based on the definitions of proprioception and coordination, one might suggest that proprioception is vital to coordination. This is supported both experimentally and theoretically. Several studies indicate that training of a single limb w i l l result in an improvement in performance of both limbs (bilateral transfer). While bilateral transfer occurs in many tasks, such as weight training and rotary task pursuit, the possibility of bilateral transfer after proprioceptive training remains unexplored. 4 Literature Review Contributions to Kinaesthesia Proprioception, also termed kinaesthesis, is our sense of body awareness, encompassing both movement position sense and static position sense (Grigg 1994 and Lephart et al 1997). Kinaesthesis is provided by afferent information from joint, skin, and muscle receptors. Although the afferent information from all three of these receptors contributes to our position sense awareness, the degree of their contribution remains unknown. Joint AfTerents Initial research indicated that join! afferents were the primary contributor to proprioception (Skoglund 1956). However, additional studies that explored the role of muscle afferents in position sense awareness discounted the key role of joint afferents in kinaesthesis (Clark and Burgess 1975 and Grigg et al 1973). In addition, joint replacement studies suggest that joint receptors do not play an important role in proprioception (Grigg et al 1973). The evidence regarding the role of joint receptors in kinaesthesis is mixed as recent studies outline the importance of joint afferents to our sixth sense (Grigg 1994, and Johannson et al 1991a and 1991b). In 1956, Skoglund provided results suggesting that joint afferents signal over the entire range of joint motion. The findings from this study indicated that each joint receptor fires over a critical angle varying in size between 15 and 30 degrees of rotation and that each critical angle overlapped with at least one other critical angle. This allows for the entire range of joint motion to be coded. However, additional studies discount Skoglund's (1956) findings and provide support against the importance of joint afferent 5 information in kinaesthesis. A study by Clark and Burgess (1975) examined the response of joint afferents, in the cat knee, to imposed movements. The results from this experiment indicate that joint receptors do not fire over the entire range o f motion, instead their results suggest that joint receptors fire at the end or at the limits of the joint range (Clark and Burgess 1975). Consequently, these results imply that joint receptors are not responsible for position sense awareness because they only code the end points of joint range of motion. Results from joint replacement surgeries also suggest that afferent information from joint receptors do not have a dominant role in position sense awareness. For example, total hip and finger joint replacements failed to diminish one's kinaesthetic sense (Grigg et al 1973); i f joint receptors were the primary source of position sense information, then the removal of a joint would decrease one's kinaesthesis. Tendon vibration studies also imply that joint afferents do not have a critical role in one's kinaesthetic awareness. Both movement and position illusions are elicited during tendon vibration o f a stationary limb, even though the information from joint receptors signal the correct joint position (Goodwin et al 1972a). If subjects rely upon joint afferent information to determine the position of their limb they would not have the illusion that their limb was moving. Similarly, kinaesthesis is diminished when joint afferents are present but muscle afferents are lost (Gandevia and McCloskey 1976). In this experiment the hand was positioned in a manner that disengaged the muscles from the terminal phalanx of the middle finger (Gandevia and McCloskey 1976). Consequently, only skin and joint afferents contributed to the movement and position sense awareness of the terminal phalanx of the middle finger during movements imposed upon this digit. Under the assumption that joint afferents play a dominant role in kinaesthesis, one would expect 6 subjects to rely on joint afferent information rather than muscle afferent information in both o f these studies. Despite the previous findings, recent studies provide results that support the role of joint afferents in one's position sense awareness suggesting that joint afferents act as nociceptors (Grigg 1994). Nociceptors act as "limit detectors" that signal when the joint is about to go beyond the limit of its normal range o f motion, thereby protecting the joint from injury. In addition, Clark and Burgess (1975) provide results suggesting that joint receptors act to protect a joint by signaling improper joint motion. In this study the joint afferents increased their firing rate when the knee joint was rotated (Clark and Burgess 1975). The knee is a hinge joint allowing for flexion and extension at the knee, therefore rotation of the knee joint leads to injury. Both of the above experiments support the role of joint receptors in kinaesthesis. Lastly, two studies by Johannson et al (1991a and 1991b) suggest that joint afferent information is vital to kinaesthesis. These two studies propose that joint receptors in the cruciate ligament indirectly control joint stiffness. According to Johannson et al (1991a and 1991b), joint afferents in the cruciate ligament regulate joint stiffness by increasing muscular tension surrounding the knee through the fusimotor system of the muscle spindle. Through an indirect control of joint stiffness, joint afferents change the acuity of the muscle spindle thereby contributing to kinaesthesis. Skin Afferents A second source of information contributing to kinaesthesia is provided by the afferent information from skin receptors. Similar to joint receptors the evidence regarding the role of skin afferents in kinaesthesis is mixed. 7 Similar to joint afferents, tendon vibration studies provide support against the role of skin afferents in kinaesthesis. When the tendon of the biceps muscle of a stationary limb is vibrated, the subject feels that his limb is extending, as i f the biceps muscle is lengthening. The illusion or perception of joint movement occurs even in the presence of information from the skin, which signals that the limb is stationary. I f subjects rely on skin afferent information to determine the position of their limb then muscle vibration would not create an illusion of joint motion. Additional studies involving skin indentation experiments discount the role of cutaneous afferent information in proprioception. In the work by Horch et al (1975), the experimenters indented the skin of the forearm. One to two minutes after the skin was indented the sensation of skin indentation disappeared, implying that skin afferent information is not a reliable source for position sense awareness (Horch et al 1975). The same study indicates that skin indentations are not perceived when the indentation rate is below O.lmm/s (Horch et al 1975), providing further support against the role of skin afferent information in kinaesthesis. Contrary to Horch et al (1975), Edin and Abbs (1991) suggest that skin afferents do have a key role in kinaesthesia. Their study used microneurography techniques to record afferent information from skin receptors in the hand. Their results indicated that ninety percent of the receptors from which they made recordings (96/107) responded to normal hand and finger movements. Thus, Edin and Abbs (1991) suggest that skin afferents respond to both static and dynamic finger positions, thereby contributing to proprioception. In addition, Moberg (1983) made several clinical observations supporting the key role of skin afferents in kinaesthesia. When information from the skin 8 and joint afferents is blocked by anesthesia leaving only the muscle afferents intact, subjects failed to perceive the movements of their fingers. Even when only the skin afferents are blocked, but both the muscle and the joint afferents are intact, the subject had no sense of passive or active movements of the finger. Results from the above studies suggest that position sense awareness is abolished with the removal of skin afferent information, implicating a role for skin afferents in proprioception. Edin and Johannson (1995) provide one of the most compelling arguments for the role of skin afferents in position sense. In this experiment, subjects had both the distal and proximal interphalangeal joints of their left index finger anaesthetized. With the finger anaesthetized, the experimenters imposed passive movements on the finger. A l l subjects reliably and correctly indicated the passively imposed movements on the anaesthetized finger. Next the experimenters imposed strain patterns corresponding to flexion and extension movements of the finger. For example, compression of the palmer surface with simultaneous stretching of the dorsal surface corresponded to the strain pattern associated with a flexion movement of the finger. Although the skin at the point of compression and stretch is insentient, the strain pattern caused a stretch or compression of the skin overlying the metacarpophalangeal joint, allowing for the detection of the strain pattern. Subjects correctly detected the imposed strain patterns on the stationary insentient finger corresponding to flexion and extension movements of the digit. Lastly, when the experimenters blocked the skin strain of the movement from reaching the metacarpophalangeal joint subjects did not perceive any movement of the insentient finger. 9 Muscle Afferents The third contribution to position sense awareness is provided by the afferent information from muscle receptors. In the late 1970's Matthews (1977) provided results indicating that muscle receptors fire over a wide range of joint positions suggesting that muscle receptors are responsible for our kinaesthetic sense. Although the contribution of each afferent source is unknown, a number of experiments involving tendon pulling, anesthesia and muscle vibration support the dominant role of muscle afferent information in proprioception. In 1974, Matthew and Simmonds provided support for the role of muscle receptors in kinaesthesis. The subjects for this experiment underwent surgery for carpal tunnel syndrome. To perform this surgery the tendons of the wrist are exposed using an anaesthetic that is administered and confined to the wrist, allowing subjects to remain conscious during the procedure. During surgery the experimenters pulled upon each subject's tendon in order to stretch the muscle without moving the limb. According to their results, subjects correctly perceived sensations of movement evoked by the experimenters pulling on the exposed tendons. Subjects perceived movement even though their fingers remained stationary. These results support the role of muscle afferent information in kinaesthesis because subjects relied on the altered afferent information from muscle receptors to determine the perceived position of their finger. I f subjects relied on the afferent information from skin and joint receptors then the subjects would not have the illusion of joint movement. More evidence for the role of muscle afferents in kinaesthesia is provided by Goodwin et al (1972b). The results from this experiment indicate that subjects retain the ability to perceive movements of their limbs 10 in the absence of any contribution from joint and skin afferents. During this experiment anaesthesia of the index finger removed the contribution of joint and skin afferents to kinaesthesis while preserving the muscle afferents. Despite the removal o f joint and skin afferents, subjects detected passive movements of the finger. This experiment implies that information from muscle afferents is sufficient to provide position sense awareness. If afferent information from skin and joint receptors is important to kinaesthesis then one's position sense awareness would diminish when skin and joint receptors are removed through anesthesia. Clark et al (1985) performed a complementary experiment in which they anaesthetized the muscles, thus blocking all information from muscle afferents while preserving the information from skin and joint afferents. The results from this experiment suggest that a loss of muscle afferent information causes a decrease in one's kinaesthetic awareness, reinforcing the role of muscle afferents in proprioception. Further support for the role of muscle receptors in proprioception is provided by studies exploring one's kinaesthetic sense during muscle contraction and after muscular fatigue. Goodwin et al (1972b) provided results suggesting that subjects correctly perceive passive movements of a limb in the absence of joint and skin afferent information, however, these imposed movements were easier to detect when each subject slightly tensed their muscles involved in the movement. In contrast, Carpenter et al (1998) found that muscular fatigue decreases position sense awareness. During this experiment subjects had to detect the onset of movement when the experimenters passively imposed movements of the shoulder. After causing fatigue of the muscles involved in the movement, the experimenters found that subjects' detection threshold increased by 73%. Consequently, subjects required a larger movement of their shoulder 11 before detecting the onset of movement. These findings imply that subjects rely on signals from muscle afferents for position sense awareness rather than information from joint and skin afferents. I f subjects relied on information from joint and skin afferents, then muscle contraction or fatigue would not affect one's position sense awareness. The most compelling evidence in support of the greater contribution of muscle afferents to kinaesthesia is provided by vibration studies. Goodwin et al (1972a) provided results indicating that vibration of a muscle induces an illusion of muscle lengthening as well as an illusion of altered joint position even though the limb remains stationary. For example, during vibration of the biceps muscle the subject felt that their forearm was moving into extension even though their limb remained stationary. Similarly, during vibration of the triceps muscle the subject felt that their forearm was moving into flexion. During tendon vibration subjects also perceive the illusion that their limb changes position. The experimenters asked subjects to place their nonvibrated limb in the perceived position of their vibrated limb. Subjects consistently placed their nonvibrated limb in a position that was up to 15 degrees of greater extension or greater flexion than the vibrated limb. Similarly, Craske (1977) indicated that subjects perceive impossible joint positions during muscle vibration. For instance, during muscle vibration subjects felt that their wrist moved about 29 degrees beyond its normal range of motion even though the limb remained stationary. Subjects also felt that someone was bending their limb backwards, or that someone was breaking their limb. The results from Craske (1977) support the role of muscle afferents in proprioception because subjects perceive impossible joint positions when their limb remained stationary. The results from both Goodwin et al (1972a) and Craske (1977) suggest that subjects rely on muscle afferent 12 information during kinaesthetic tasks, rather than relying on the appropriate skin and joint afferent information. Additional vibration studies provide support for the role o f muscle afferent information in kinaesthesia. Inglis and Frank (1990) asked subjects to match the perceived position of their right (vibrated) limb with their left (nonvibrated) limb. During this experiment subjects performed horizontal flexion and extension movements of their right limb while the experimenters vibrated either the triceps or the biceps muscles of the right limb. During a flexion movement of the forearm, vibration over the biceps muscle (agonist) had no effect on the perceived position of the limb, however vibration over the triceps muscle (antagonist) caused the subjects to perceive their limb in a more flexed position than its actual position. This result implies that subjects rely on afferent information from the antagonist muscle when performing kinaesthetic tasks. A follow-up study by Inglis et al (1991) suggests that afferent information from the lengthening muscle is important in kinaesthetic perceptions, whether it acts as the agonist or antagonist muscle during a movement. Similar to their previous experiment, the experimenters vibrated the biceps or the triceps muscles during a flexion movement. However, unlike the previous experiment, the triceps muscle was actively contracting, and controlling the movement even though it was lengthening throughout the movement. A s a result, vibration of the shortening muscle (biceps brachii) did not alter position sense of the limb, but vibration of the lengthening muscle (triceps brachii) caused subjects to perceive their limb in a more flexed position than its actual position. Thus the studies by Inglis et al. (1990 and 1991) provide support for the role of muscle afferent information 13 in kinaesthesia. In addition, they suggest that afferent information from the lengthening muscle determines the perceived position of a subject's limb. O f the three afferent sources contributing to kinaesthesia the muscle spindle may code differently during active and passive movement. The muscle spindle is unique because it has both an afferent and an efferent connection. During active movement the gamma system provides efferent innervation to the muscle spindle to prevent slackening of the spindle when the muscle contracts. The efferent innervation changes the sensitivity of the muscle spindle during active movement so that the spindle can code the changes in muscle length during active movement. In contrast, only the afferent information from the muscle spindle is present during passive movement. Consequently, the slack in the muscle spindle created by the shortening of the muscle during passive movement is not removed because there is no efferent innervation. Although the spindle continues to send afferent information to the cortex during passive movement this information may by different from the afferent information that is sent to the cortex during active movement. The efferent innervation provided by the gamma system during active movement suggests that the spindle may code differently during active and passive movement. Position sense information is provided by the combined contribution of joint, skin and muscle afferents. Although all three afferents play a role in position sense awareness the degree of contribution to proprioception from each afferent source remains unknown. Proprioception is an inherent sense, similar to our sense of vision or our sense of smell, however individual levels of position sense awareness vary between subjects. 14 Individual Levels of Proprioceptive Awareness Proprioception is often defined as our "sixth sense" (Allegrucci et al 1995). Similar to our other five senses, kinaesthesia varies between individuals and between different populations. Many of the variations in position sense awareness observed among subjects are related to variations in gender, age, current physical activity level, and laterality (Freeman and Broderick 1996, Bairstow and Laszlo 1981 and Barrack 1995). Several studies provide conflicting results regarding the varying level of kinaesthesis between genders. For example, Freeman and Broderick (1996) found that on a kinaesthetic acuity task of the upper limbs male subjects had a better sense of kinaesthesia than female subjects did. However, on a kinaesthetic perception and memory task of the upper limbs they found that female ballet dancers outperformed their male counterparts. A separate study by Barrack et al (1984) found that male and female control subjects did not differ from each other in their kinaesthetic awareness. The experimenters used a movement detection task to measure kinaesthetic awareness such that subjects had to signal any movement or change in position of their leg. However, the experimenters found that male dancers demonstrated a greater sense of kinaesthetic awareness than female dancers on the same movement detection task. Although Barrack et al (1984) found a difference between male and female dancers the results were not statistically significant. A third study by Laszlo and Bairstow (1980) did not find any significant difference in the performance between males and females of any age group. The issue of gender differences in kinaesthesis remains unresolved. 15 Age is another common variable in which differences in performance are found. For example, performance on a motor skill generally improves with age until it reaches a plateau; after which performance on the same motor task declines (Kottke 1980). In addition, Kaplan et al (1985) performed an experiment examining the differences in kinaesthesia between two different age groups. This experiment tested "younger" subjects (below thirty) and "older" subjects (above sixty). This experiment used two tasks to measure kinaesthesia. The first task required subjects to match the perceived position of each knee with the contralateral knee. The second task required subjects to replicate a target angle with the knee. The results from this study imply that "younger" subjects have a greater sense of kinaesthetic awareness than "older" subjects do. A n additional study by Laszlo and Bairstow (1980) examined the proprioceptive differences between developing children and adults. This experiment used a kinaesthetic acuity task and a kinaesthetic memory and perception task to measure kinaesthetic awareness. Their results indicate that adults have a greater position sense awareness than children. Moreover, a follow-up study by Bairstow and Laszlo (1981) found that kinaesthesis improves throughout childhood with the greatest improvements in performance occurring between six and eight years of age at which point the proprioceptive acuity of children is similar to adults. In addition, several studies postulate that there are kinaesthetic differences between athletes and non-athletes. For example, the results from several experiments consistently indicate that athletes have a greater sense of kinaesthetic awareness than non-athletes do (Freeman and Broderick 1996, Barrack et al 1995, Euzet and Gahery 1995 and Bairstow and Laszlo 1981). However, most of these studies included ballet 16 dancers and gymnasts in their athletic group of subjects. According to Euzet and Gahery (1995) the training of ballet dancers and gymnasts focuses on position sense awareness, suggesting that these athletes have a greater sense of kinaesthetic awareness than other athletes do as a result of training. Consequently a bias in favor of a greater kinaesthetic performance for the athletes may exist in the above results because of the inclusion of ballet dancers and gymnasts. In order to avoid this bias, Euzet and Gahery (1995) included football players and archers among their athletic group of subjects. Both the football players and archers demonstrate greater position sense awareness than control subjects even though their training does not focus on position sense awareness. Accordingly, Euzet and Gahery (1995) concluded that athletes, regardless of their sport, have a better kinaesthetic sense than non-athletes do. Individual differences in kinaesthetic awareness are also found between subjects from the general population. Birmingham et al (1998) studied the changes in proprioceptive acuity o f the lower limb during the application of a neoprene sleeve over the knee among 36 healthy volunteers. The results suggest that several subjects have inherently good position sense awareness, while other subjects have an inherently poor position sense awareness. The above studies consider the variability between subjects, however variability may also exist within subjects. The possibility of a difference in kinaesthesis between the limbs receives little attention and the few studies that included the testing o f both limbs in their protocol failed to find a difference in performance between limbs. For example, Laszlo and Bairstow (1980) failed to find any significant difference in the performance of the left and right upper limb of right-handed subjects. In addition, both Barrack et al (1984), and Euzet and Gahery (1995) failed to find any significant difference in the 17 performance between the left and right legs among their subjects. Although a small difference exists, it was not statistically significant. Even though the above studies did not find any difference between the dominant and non-dominant limbs, additional studies may provide conflicting results Although the methods of the above experiments are not discussed in this paper, it is worth noting that each of these experiments used a different method of testing and measuring kinaesthetic performance. The variability between tests and measures may account for some of the conflicting results in the above findings. While some of the differences in position sense awareness between subjects may disappear with one test of kinaesthesia, the differences in the same subjects may become more evident with an alternate test. Although all o f these tests are valid, the relationship among the various tests remains unclear, for example, would test ' A ' and test ' B ' provide an equal measure of kinaesthesis in a given subject? In addition to the large variety of tests, one can also choose to perform a test either actively or passively, providing an additional component to consider when measuring one's kinaesthetic sense. Active versus Passive Kinaesthetic Sense There are many tests available to assess one's sense of kinaesthesia, such as angle replication, detecting the onset of an imposed movement and the simultaneous identification of both the onset and the direction of an imposed movement. Within the framework of these tests one can chose to administer the tests either actively or passively. One might assume that subjects yield a greater performance on an active test since muscular contraction increases one's level of kinaesthesia, however studies that focus on 18 measuring one's kinaesthetic awareness in both an active and passive condition provide conflicting results. L loyd and Caldwell (1965) performed an experiment comparing subjects' kinaesthetic sense during an active task versus a passive task. The results suggest that while subjects overestimate a passively positioned limb, they replicate with greater accuracy an actively positioned limb. Similarly, Paillard and Brouchon (1968) provide results suggesting that a subject's kinaesthetic sense is more accurate during an active task than during a passive task, and that subjects tend to overestimate a passively positioned limb. Eklund (1972) replicated these results. In contrast to the results of Paillard and Brouchon (1968) a study by Birmingham et al (2000) implies that subjects passively replicate a target angle with greater accuracy than actively replicating the same target. During this study subjects either passively or actively replicated a passively positioned knee. In earlier studies subjects actively replicated either their passively or their actively positioned limb. In contrast, Birmingham et al (2000) required subjects to actively or passively replicate their passively positioned limb. The difference in methodology between earlier studies and Birmingham et al (2000) may account for the discrepancy in results. In addition, Birmingham et al (2000) tested the knee joint while Paillard and Brouchon (1968) tested the upper limb, which may also account for the discrepancy in results. According to the studies outlined above one cannot conclude that the active condition is superior to the passive condition. Regardless of the variety of tests several studies indicate that one's kinaesthetic awareness improves with training. 19 Training Kinaesthesia Position sense awareness varies between individuals and between the variety of tests. Regardless of the factors affecting kinaesthesia, several studies suggest that one's level of position sense awareness improves after kinaesthetic training. To illustrate, Laszlo and Bairstow (1983) trained eleven, seven-year-old children on a proprioceptive acuity task. Their results indicate that task performance improves after training when compared to untrained children. Their results also indicate that the children retain their improved performance eight weeks after training. In the same study, Laszlo and Bairstow (1983) trained fourteen, seven-year-old children on a proprioceptive memory task. As a result of the training, the children showed a significant improvement in performance on the memory task when compared to untrained children. Both the proprioceptive acuity and the proprioceptive memory training suggest that kinaesthesis improves with training. Before training, however, the proprioceptive performance of the children in this study was not at a level similar to that of adults. Hence, it is possible that the training protocol only accelerated the development of the children's kinaesthetic sense. In a separate study Fry-Welch (1998) used an alternate kinaesthetic training method with adult subjects. The results indicate that the kinaesthetic performance of adult subjects improves after training when compared to untrained subjects. Two additional studies also indicate that kinaesthetic performance can be improved (Perlau et al. 1995, and Birmingham et al. 1998), yet neither study used kinaesthetic training. Instead, the researchers improved kinaesthetic awareness by enhancing the proprioceptive information available to each subject. For example, Perlau et al (1995) applied an elastic 20 bandage to each subject's knee, while Birmingham et al (1998) applied a neoprene sleeve to each subject's knee. Both studies found that proprioceptive performance improved after the knee applications. Studies with children and adults suggest that kinaesthetic performance improves after training regardless of one's initial kinaesthetic acuity. Kinaesthesis varies between individuals such that some individuals have poor position sense awareness while others have inherently good kinaesthetic awareness. Regardless of one's inherent level of position sense awareness, kinaesthesis improves with training or when the proprioceptive information is enhanced. Coordination Coordination is "the behavior of two or more joints in relation to each other to produce skilled activity" (Schmidt 1988, p265). Accordingly, coordination tasks include multijoint movement sequences such as locomotion, throwing, speech, and keyboarding (Cordo et al 1995). The list of coordinated tasks is endless, suggesting that the brain lacks the capacity to store a memory for each task. Consequently, several theories exist explaining our ability to perform multiple movements without the need for a memory for each individual task. Theories of multijoint movement include the motor program and schema theories. Schmidt suggests that individuals develop a motor program to perform coordinated tasks (Schmidt 1988, p225). A motor program is defined as the development of an abstract representation of a movement producing a coordinated sequence when it is initiated. Sensory information is crucial to the development of a motor program as it is used before, during and after a given movement. Hence, sensory information during the three phases 21 of movement allows for an individual to adjust the motor program to improve performance on a subsequent movement. Another theory called the schema theory, suggests that a person develops a "rule, concept, or relationship formed on the basis of experience" to perform a movement (Schmidt 1988 p491). According to this theory the central requirements of the task are important, while the details are less important. Furthermore, its framework is made up of two schemas: recall and recognition. The recall schema, concerned with the production of movement, develops a relationship between the outcome of the movement and the past parameters used to create this outcome. The recognition schema, concerned with response evaluation, develops a relationship between movement outcomes, initial conditions and the sensory consequences produced by these combinations (Schmidt 1988, p484-486). Additional coordination theories include the response-chaining hypothesis, the equilibrium-point model and the impulse-timing model. The response-chaining hypothesis asserts that each subsequent event of a movement is triggered by the sensory feedback o f the previous event (Schmidt 1988, p225). The equilibrium-point model argues that an equilibrium point between the agonist and the antagonist muscles facilitating the movement (Schmidt 1988, p224) determines the end-point of a movement. The impulse-timing model proposes that the "movement trajectory is determined by impulses that determine the amount and timing of applied forces" which are required to achieve a goal (Schmidt 1988, p224). Motor skills and coordination develop until roughly about 18 years of age, peak around 25 to 30 years of age, and then afterwards decline with age (Kottke 1980). Despite the decline in coordination after age thirty, coordination may be maintained or 22 improved through practice of the task. The training of coordination involves perception, precision, perpetual practice, peak performance and progression (Kottke et al 1978). O f these five components, perception is provided by one's kinaesthetic awareness, suggesting that kinaesthesis has a role in coordination. In addition, Kottke et al (1978) recommend breaking down coordinated activities into smaller components of the entire movement so that these units can be practiced in isolation before performing the entire activity. Consequently, improving a subject's sense of kinaesthesia, a component of coordination, may improve their coordination on a multijoint movement task. A l l o f the coordination theories implicate the importance of proprioception in coordinated tasks. For example, the motor program theory, schema theory and response-chaining hypothesis suggest that sensory feedback is vital to multijoint movement sequences. While the equilibrium-point and impulse-timing model suggest that muscle properties are used to perform a movement. Previous research suggests that muscle plays a dominant role in proprioception, consequently the importance of proprioception in the equilibrium-point and impulse-timing model is implicated. A role for proprioception in coordination is also implicated by the training of motor skills. Both the theories and the experiments involving coordination training suggest that kinaesthesis plays a vital role in coordination. Additional studies support a relationship between kinaesthesis and coordination. Coordination is involved in the majority of all our everyday tasks. Both the theories and the training of coordination implicate the importance of kinaesthesis in multijoint movements. 23 Stages of Motor Learning Schmidt (1988) discusses several sources which suggest that subjects pass through three different stages when learning a new skill (Schmidt 1988, p460). These three stages are the cognitive phase, the associative phase and the automatic phase. The first stage of learning is the cognitive phase and it is characterized by dramatic gains in performance. Performance during this stage is usually inconsistent as the subject learns the appropriate strategies for performing the task. The second stage of learning is the associative phase and it is characterized by subtle performance adjustments. During this phase "performance improvements are more gradual and movements become more consistent" (Schmidt 1988, p460). The second stage of learning can last for several days or many weeks. The third and final stage of motor learning is the automatic phase. Learners do not enter this phase until they have spent several months or even years practicing the task. During this phase the performance of the task is more or less automatic such that subjects can perform the task while simultaneously performing alternate tasks. A s this phase is termed "automatic" very few changes in performance occur during this phase. Both the absolute constant error and the variable error are measures that can assess one's performance during the three stages of motor learning. Absolute constant error measures the bias in performance, while variable error measures the consistency o f performance. Both error scores are probably very large during the beginning of the cognitive phase of learning as performance is usually very inconsistent during this stage. However, the cognitive phase is also characterized by dramatic performance gains, consequently both of the error scores are probably reduced during the later stages of this 24 phase. When learners reach the associative phase their performance becomes more consistent, accordingly the variable error score is continually reduced during this stage. Finally, when learners reach the automatic phase their performance becomes more or less automatic. Consequently, there are probably no changes to the two error scores during this stage of motor learning. A Relationship between Kinaesthesis and Coordination Kinaesthesis is one's sense of body awareness including sensations of joint position and joint motion (Barrack et al 1984 and Grigg 1994). Coordination, on the other hand, is defined as "the behavior of two or more joints in relation to each other to produce skilled activity" (Schmidt 1988 p.265). The above definitions suggest that performance on coordinated tasks rely on kinaesthetic awareness (Schmidt 1988 and Kottke et al 1978). Several studies provide results supporting a relationship between coordination and proprioception. Both Schmidt (1988) and Kottke et al (1978) proposed a role for proprioception in coordination. Schmidt (1988 p.228) postulates that kinaesthetic awareness is important before, during and after a given movement, while Kottke et al (1978 p.570) suggest that kinaesthetic awareness serves mainly as a feedback mechanism at the end of a given movement. Although proprioceptive feedback is available during movement, some evidence implies that this feedback occurs too slowly to be of use during movement (Kottke et al 1978). In contrast, Schmidt (1988 p.486) suggests that kinaesthetic feedback is used at varying times during movement depending on the movement speed. Despite the opposing views of Schmidt (1988) and Kottke et al (1978), several studies 25 provide results supporting the vital role of kinaesthetic awareness in multijoint coordination. In an effort to provide a greater understanding of the role between kinaesthesis and coordination, several authors repeatedly tested the coordination of patients with large fiber sensory neuropathy. By nature, the kinaesthetic awareness in the limbs and the extremities of neuropathy patients is diminished. Consequently, these patients have difficulty with fine coordination tasks such as buttoning their clothing and bringing food to their mouths using a fork and a spoon. In 1993 Sainburg compared the performance of a slicing gesture (similar to slicing a loaf of bread) between a control group and subjects with large fiber sensory neuropathy. The results suggest that the performance of neuropathy patients is worse than the performance of the control subjects. Neuropathy patients' performance was less linear and less planar than controls. An additional study by Gordon et al (1995) compared the performance on a reaching task between two neuropathy patients and a control group. Similar to Sainburg et al (1993), the results indicate that the performance of both neuropathy patients is more impaired than controls. Their performance was less accurate, showing errors in both the direction and the extent of their movement. The results from these two studies imply that kinaesthetic awareness is important to the programming and the planning of multijoint movements. Results from both studies indicate that kinaesthetic awareness is vital to coordination. An additional study by Cordo (1990) examined the role of kinaesthesia in a multijoint movement sequence, this time, among healthy individuals. The coordination task in this experiment was similar to that of a Frisbee toss, such that subjects had to open their thumb and index finger as their elbow passed through a target. The results from this 26 study suggest that subjects use kinaesthetic information to correct errors while performing a movement and to trigger the movement of other joints during a multijoint task. The definitions of kinaesthesia and coordination suggest that they are intimately linked. According to coordination theories, the speed of movement may determine how kinaesthesia contributes to coordination (Schmidt 1988 and Kottke et al 1978). Regardless of when kinaesthetic feedback is used during a multijoint task studies using both neuropathy patients and healthy volunteers suggest the importance of kinaesthesis in coordination. Bilateral Transfer Can the training of one limb affect the performance of the contralateral, untrained, limb? This question is addressed by several studies, and many of these studies show that bilateral transfer occurs between limbs for a variety of tasks (Yue and Cole 1992 and Byrd et al 1986). In addition, one of these studies indicates that limb dominance and age affect bilateral transfer. In a study by Yue and Cole (1992) subjects performed a maximal voluntary contraction ( M V C ) of their left hypothenar muscles causing abduction of the left fifth finger. After twenty training sessions the experimenters compared the strength changes of the left hypothenar muscles between the training and the control (untrained) group. In addition, the experimenters compared the strength gains of the right untrained hypothenar muscles between the two groups. The increase in strength of the left (trained) hypothenar muscles of the control and M V C group was 3.7% and 29.75% respectively. While the 27 increase in strength of the right (untrained) limb for the control and M V C groups was 2.3% and 14.43% respectively. The results from testing the contralateral, untrained, limb suggest that bilateral transfer occurs during strength training. A separate experiment by Byrd et al (1986) explored the effects of bilateral transfer among females between 7 and 17 years of age performing a rotary pursuit-tracking task. Subjects performed a series of trials tracking a target with one limb and then performed the same task with their contralateral limb. The experimenters measured performance as the time tracking the target. Half of the subjects performed the first set of trials with their preferred hand followed by a set of trials with their contralateral hand. The remaining subjects performed the first set of trials with their non-preferred hand followed by a set of trials with their preferred hand. The results from this experiment indicate that bilateral transfer also occurs during a rotary pursuit-tracking task. Secondly, the results indicate that bilateral transfer is greater when subjects perform the first set of trials with their preferred limb. Thirdly, the findings indicate that transfer is greater among the older, 17-year-old subjects, implying that older subjects gain more benefit from bilateral transfer. Several studies provide results suggesting that bilateral transfer occurs between limbs. While the number of tasks in which bilateral transfer occurs and the amount of training required for it to occur are not outlined, the potential clinical benefits are endless. For example, bilateral transfer can potentially be used to decrease practice time (Dunham 1977) and maintain the strength of an injured limb by training the contralateral, uninjured limb. In addition, transfer could potentially be used to strengthen or improve the function 28 of hemiparetic limbs among stroke patients or to improve limb function among subjects with a neuromuscular disorder such as multiple sclerosis or cerebral palsy. Findings from the two studies above imply that cross education occurs in both strength training and rotary pursuit-tracking tasks. The results also suggest that both limb dominance and age affect bilateral transfer. While both studies provide positive results, several questions regarding bilateral transfer remain unanswered. For example, does kinaesthetic training of one limb improve the kinaesthetic awareness of the contralateral untrained limb? 29 Summary of Hypotheses The primary purpose of this experiment is to observe any improvements in coordination after kinaesthetic training. Accordingly the first hypothesis is that proprioceptive training improves coordination. To test this hypothesis performance on a task involving coordination wi l l be evaluated before and after kinaesthetic training. Only the subjects from the two training groups (group two and group three) wi l l undergo kinaesthetic training, while subjects from the control group (group one) w i l l not receive any training. Comparison of the coordination performance measures before and after the training sessions wi l l display any improvements in coordination. If coordination improves after training, one must assume that proprioceptive acuity also improves after training. Consequently, an inherent hypothesis of this experiment is that proprioceptive acuity improves after proprioceptive training. In addition to testing coordination before and after training, the kinaesthetic awareness o f the control and trained subjects wi l l be tested before and after training. Comparison of the kinaesthetic performance measures before and after the training sessions wi l l display any improvements in proprioceptive acuity. The second purpose of this experiment is to observe any improvements in coordination or proprioceptive acuity of the left limb after proprioceptively training the right limb. Therefore the third hypothesis is that training will improve the performance of the contralateral (untrained) limb. To test this hypothesis both the coordination and proprioception of the left limb of all subjects wi l l be tested before and after the kinaesthetic training protocol. Comparison of the coordination and 30 proprioceptive performance measures before and after the training sessions wi l l display any improvements in the left, untrained limb. Finally, it is important to know i f proprioceptive training has any lasting effects. To test any long-term effects of kinaesthetic training, subjects from the two training groups wi l l participate in two retention tests following the post-training session. The performance measures from the two retention tests wi l l be compared to the performance from the post-training test to determine the extent of the retention. 31 Chapter H Methodology Subjects A total o f twenty-one right hand dominant, healthy female subjects between the ages of 18 and 30 (average age was 24) volunteered to participate in this study. Subjects did not have any previous musculoskeletal injuries of the upper limbs within the previous five years, and they did not have any known neurological disorders. Seventeen o f the twenty-one subjects participate in regular exercise (aerobic or strength training exercise at least three times per week). Most of the subjects have participated in a variety of sports at a recreational level except for one subject who was a national runner, one subject who was a national cyclist and two subjects who are varsity soccer players. Prior to participation all subjects read and signed an informed consent form in accordance with the guidelines provided by the University o f British Columbia. In addition, all subjects completed an activity questionnaire prior to testing. Subjects were divided into three equal groups consisting of a control (group one) and two experimental groups. Subjects who could only participate for two days were automatically placed in the control group. A l l other subjects were randomly placed in one of the two experimental groups. The two experimental groups consisted of an actively trained group of subjects (group two) and a passively trained group of subjects (group three). Procedure For all testing and training, subjects wore a short sleeved shirt or a thin long sleeved shirt and they were seated in a chair with their arm abducted by approximately 60 32 degrees, their elbow flexed to an angle of approximately 30 degrees, with their forearm semipronated. Each subject's elbow was placed over the axis of rotation of the lever arm (manipulandum) and the forearm was placed in a u-shaped cuff that allowed for horizontal flexion and extension of the forearm. Refer to figure 1 for a schematic representation. The wrist was placed in a rigid splint to prevent any movement of the wrist and forearm. Subjects were seated and braced against a high back chair using a waist belt and two shoulder straps, which prevented any changes in posture during the testing and training sessions. In order to minimize any changes in the position of each subject between the different days of testing the manipulandum was always placed in the same position with respect to the chair. Throughout the experiment all subjects were blindfolded, in order to prevent the use of any visual cues. During the coordination tests one copper plate was attached to the thumb and one copper plate was attached to the index finger of all subjects. The copper plate on the thumb was taped to a positive wire while the copper plate on the index finger was taped to a negative wire. These two copper plates acted as a current switch. When the two plates were in contact the signal measured zero volts and when the two plates were apart the signal measured five volts. The current switch was removed for the kinaesthetic training and testing trials. Throughout the kinaesthetic training sessions surface recording electrodes were placed over the biceps and triceps muscles of subjects in the passively trained group in order to monitor the electromyographic ( E M G ) data from these muscles. The E M G data served only to ensure that the subjects in the passively trained group were relaxed during their training sessions. 33 On the first day of testing, each subject was trained to move her limb at approximately 50 degrees per second. After learning the speed of movement all subjects provided a baseline measure of coordination and proprioception for both their right and left upper limb at a proximal and distal angle. Control subjects returned approximately ten days after the baseline testing to provide a second measure of coordination and proprioception of their right and left limb at both target angles. Within one week of providing the baseline measures, subjects from the two training groups returned for four consecutive days of proprioceptive training of the right limb. On the fifth consecutive day all o f the training subjects returned for re-testing of the coordination and proprioception of their right and left limb at both target angles. In addition, subjects from the two training groups returned for re-testing of the coordination and proprioception of both of their arms one and three weeks following training. To prevent the use of timing and distance cues during the testing and training sessions a random starting angle between 20 and 30 degrees was used for each trial. Hardware The manipulandum was designed to allow for low friction rotation about the elbow in the horizontal plane. The manipulandum consisted of a lever arm, a shaft, a potentiometer, a support block, an adjustable wrist support and a plum line. The lever arm was placed on top of the shaft allowing for rotation about a central axis. The shaft was placed in a series of support plates allowing the central axis to be maintained. A high precision, full rotation, linear potentiometer that was mounted to the bottom of the shaft displayed the position o f the lever arm on a computer screen. A n adjustable rigid 34 hand support mounted to the distal end of the lever arm prevented flexion and extension of the wrist, and supination or pronation of the hand and forearm. The hand support could be adjusted either proximally or distally from the axis of rotation to accommodate for differences in forearm length. A n I B M Pentium installed with the Spike2 (version 2.0) software program, the C E D 1401 interface, a linear potentiometer, an attenuator and a current switch were used to collect all o f the data. A fifteen-volt power supply provided current to the potentiometer. Current passed from the power supply to the potentiometer, through an attenuater and to the C E D 1401 before being converted for entering the computer. The potentiometer displayed a value between positive and negative five volts on the computer screen. The system was calibrated on three separate occasions to ensure that the potentiometer provided a reliable output. Spike! The Spike2 software program is a computer application that displays and records the sampled data. This software program can be used to create a variety of sampling configurations that allows one to choose the number of channels, the sampling frequency and the length of recording. In addition, this program displays on-line recording o f the output so that the experimenter can view the data as it is being sampled. However, the Spike2 software program wi l l only display values between positive and negative five volts. 35 C E D 1401 The C E D 1401 interface must be used with the Spike2 software program to sample data. The C E D 1401 acts as an analog to digital board so that the signal can be viewed on the computer screen. Potentiometer A high precision, full turn, linear potentiometer purchased from Electrosonic was used during this experiment. The signal from the potentiometer was sampled at 100 H z and one volt equaled approximately 16 degrees of rotation. The signal from the potentiometer was both reliable and accurate. Prior to the beginning of the experiment the signal from the potentiometer was sampled for two or three continuous minutes while the lever arm remained stationary to ensure that the signal did not drift during that time frame. This method of analyzing any drift in the signal from the potentiometer was carried out on several occasions both immediately after the equipment was turned on and after the equipment was used for about half an hour. In addition, the signal was repeatedly recorded with the lever arm in a series of positions to ensure the accuracy o f the signal. Furthermore the potentiometer had the capacity to measure angles to an accuracy o f less than 0.5 degrees of rotation. Attenuator The voltage from the potentiometer ranged between positive and negative fifteen volts, however the computer only reads values between positive and negative five volts. The attenuator reduced the current passing from the potentiometer to the C E D 1401. Consequently, the attentuator allowed the testing range of the lever arm (20 to 170 degrees) to be recorded between positive and negative five volts. I f the attenuator was 36 not used, the computer program would not be able to display the range of the potentiometer used in this experiment. Current Switch The current switch consisted of two wires (one positive and one negative) connected to a single B N C cable. A nine-volt power supply connected to the B N C cable provided current to the switch. Current passed from the power supply to the switch and then to the C E D 1401 before entering the computer. Black electrical tape attached each wire to a separate copper plate. Adhesive tape attached one copper plate to the subject's index finger, and the other copper plate to the subject's thumb. When the plates were in contact the signal measured zero volts and when the plates were apart the signal measured five volts. Calibration A large protractor constructed from cardboard was placed beneath the lever arm. The vertex of the protractor corresponded to the axis of rotation of the manipulandum. A plum line from the end of the lever arm allowed for accurate positioning and repositioning of the lever arm over the degrees of rotation displayed on the cardboard protractor. The plum line was a pinpoint of light from a laser pointer mounted on the end of the manipulandum. The potentiometer was calibrated three times to ensure that it provided a consistent and accurate measure. For each calibration the lever arm was positioned over the protractor at five-degree increments between 20 and 160 degrees of rotation. The position of the lever arm at each of the five degree increments was recorded, copied and transferred to an excel file, where a graph and a polynomial equation were created. The polynomial equation [angle = (-0.068*(y)A2)+(15.949*(y))-37 2.9826] was used to convert the recorded voltage values into the corresponding degrees of rotation. E M G Muscle activity was monitored from the upper arm of all passively trained subjects by placing one pair of recording electrodes on the belly of the biceps muscle and one pair of recording electrodes on the belly of the triceps muscle. In addition, one recording electrode was placed on the fifth metacarpal to act as a ground. Before placing the electrodes, the skin was prepared by rubbing the area with sandpaper in order to remove any dead skin cells, afterwhich the area was cleaned with alcohol. Two nine-volt batteries provided power to the preamplifying unit of the E M G system. The E M G signal was amplified 15000 times before entering the computer and all E M G data was collected at 100 Hz . Muscle activity is usually collected at a higher frequency in order to prevent aliasing of the signal. However, in this experiment the E M G served only as a visual source of data to ensure that the biceps and triceps muscles of the passively trained subjects remained relaxed throughout the training paradigm. Data Collection Protocols Velocity of Movement Training Before testing began all subjects learned to move their limb at a velocity between 45 and 55 degrees per second (+ or - five degrees). To learn this speed o f movement subjects moved their limb, with the use of vision, a distance of 100 degrees within two beats of a metronome. The metronome was set at a cadence of one beat per second. Subjects continued to perform the movement in time to the metronome until they were 38 comfortable with the speed of movement. Throughout the experiment the principal investigator subjectively monitored the speed of movement. I f subjects moved too fast they were reminded to use a slow and controlled movement. In contrast, i f subjects moved too slow they were instructed to move slightly faster. Coordination Testing Protocol The coordinated movement task is similar to throwing a Frisbee. Subjects had to extend their elbow from a random starting position between 20 and 30 degrees. During the limb extension subjects had to open their thumb and index finger as their elbow passed through a target angle. Refer to diagram 2 for a schematic representation. Before testing began, subjects received a visual demonstration of the task and verbal instructions on performing the task. Subjects were instructed to extend their forearm and open their thumb and index finger as their forearm passed through the target. Subjects were instructed not to stop at the target, but to extend their limb through the target and stop shortly after opening their thumb and index finger. In addition, subjects were instructed that they would receive the target position only once before performing ten trials at the target angle. During the testing trials, the experimenter passively moved each subject's forearm to one of two target angles (55 and 115 degrees), and passively returned the limb to a random starting angle between 20 and 30 degrees of rotation. Presentation of each target lasted a duration of four seconds. Subjects then performed ten consecutive trials at the first target. After saving the data from the first ten trials, the second target angle was presented to the subject, followed by ten consecutive trials at the second target. Before performing the second set of ten trials, subjects were re-instructed to extend their limb 39 while opening their thumb and index finger as their limb passed through the target. The proximal target was always presented before the distal target and the right limb was tested first for three of the subjects from each group while the left limb was tested first for four of the subjects from each group. The presentation order of the two targets remained the same for each session in order to maintain consistency between subjects. Kinaesthetic Testing Protocol The kinaesthetic testing consisted of an angle replication task. Subjects had to extend their limb from a random starting position between 20 and 30 degrees and then stop their limb when they felt that it had reached the target. Before testing began subjects received a visual demonstration of the task and verbal instructions on performing the task. Subjects were instructed to extend their limb and stop at the target. In addition, they were informed that they could make one correction to their movement i f they felt they had over or undershot the target. After replicating the target angle subjects were instructed to indicate the end of their movement by saying ok, so that the experimenter could mark the end of the movement on the screen. Subjects were also instructed that they would only receive the target once before performing ten trials at the target. During the testing trials the experimenter passively moved each subject's forearm to one of two target angles (55 and 115 degrees of rotation) and passively returned the limb to a random starting position between 20 and 30 degrees of rotation. Presentation of each target lasted a duration of four seconds. Subjects then performed ten consecutive active replication trials at the first target angle. After saving the data from the first target, subjects were presented with the second target angle. Subjects then performed ten 40 consecutive trials at the second target angle. The proximal target was always presented before the distal target and the right limb was tested first for three of the subjects from each group, while the left limb was tested first for four of the subjects from each group. On each day o f testing subjects were evaluated on the following eight conditions: 1. Coordination of the right limb at the proximal target (CRP) 2. Coordination of the right limb at the distal target (CRD) 3. Coordination o f the left limb at the proximal target (CLP) 4. Coordination of the left limb at the distal target (CLD) 5. Kinaesthesis o f the right limb at the proximal target (KRP) 6. Kinaesthesis of the right limb at the distal target ( K R D ) 7. Kinaesthesis o f the left limb at the proximal target ( K L P ) 8. Kinaesthesis of the left limb at the distal target ( K L D ) Active Kinaesthetic Training Protocol During the active kinaesthetic training sessions subjects actively replicated a series of proximal (less than 90 degrees) and distal (greater than 90 degrees) target angles with their right limb in blocks of five trials. After each replication, subjects received feedback about their movement that included the magnitude and direction of their error. A t the beginning o f this training protocol subjects were passively presented with one of four proximal (between 30 and 90 degrees) targets and passively returned to a random starting position. The presentation o f each target lasted for four seconds. Subjects then actively replicated the target, and made one correction to their movement i f they felt they had over or undershot the target. When subjects completed the movement their limb was repositioned at the target to provide feedback about the magnitude and direction of their error. For example i f a subject moved her limb to a position of 60 degrees and the target was 55 degrees, the experimenter passively moved the subject's limb to the correct target of 55 degrees and indicated that this is the target before returning the limb to the starting position. Refer to figure 3 for a schematic 41 representation. Subjects performed five consecutive replications of the first target, receiving feedback after every trial. Presentation of a second proximal target followed by five consecutive replications at that target followed the first target. Once again subjects received feedback after every trial. The same protocol was used for the two remaining proximal targets and the four remaining distal targets (between 90 and 160 degrees). The targets were the same on each day of training. The four proximal targets were always presented before the four distal targets, however, the presentation order of the four proximal and four distal targets varied on each day of training. Passive Kinaesthetic Training Protocol For this training protocol, subjects passively replicated a series of proximal (less than 90 degrees) and distal (greater than 90 degrees) target angles with their right limb in blocks o f five trials. The active and passive training groups received the same set of target angles. After each replication, subjects received feedback about their movement that included the magnitude and direction of their error. At the beginning of this protocol each subject's forearm was passively moved to one of four proximal targets and then passively returned to a random starting position. Presentation of each target lasted for four seconds. Next, the experimenter passively moved each subject's limb into extension. A l l subjects were instructed to tell the experimenter to stop the movement when they felt that their limb reached the target. After making the initial stop subjects were permitted to ask the experimenter to make one correction to their movement. To make the correction, subjects asked the experimenter to move their limb into flexion or extension. Once again, subjects had to tell the 42 experimenter to stop the movement when they felt that the correction was made. After replicating the target, the experimenter moved each subject's limb to the correct target angle in order to provide feedback about the movement before returning the limb to a random starting position. For example i f a subject moved her limb to a position of 60 degrees and the target was 55 degrees, the experimenter would passively move the subject's limb to the correct target of 55 degrees. The experimenter would indicate this position as the correct target before returning the limb to a random starting angle. Refer to figure 3 for a schematic representation. Subjects performed five consecutive replications at the first proximal target, with feedback after each trial, followed by five consecutive replications at each of the remaining proximal and distal targets. Each target was passively presented once before each set of five replications. On each day of training, subjects completed the four proximal targets before completing the four distal targets, however, the presentation order of both the proximal and distal targets varied on each day of training. Recording and Collecting Data The spike 2 (version 2.0) software program was used to view and record the output from the potentiometer, the current switch and the E M G unit. Using the Spike 2 software program sampling configurations were created to permit simultaneous viewing of the different outputs. A l l outputs displayed a value in volts on the computer screen and all o f the data was collected at 100 Hz . Coordination Testing Data. A sampling configuration with two channels was constructed to record all o f the coordination data; one channel for the output from the potentiometer and the second channel for the output from the current switch. Both 43 channels were viewed simultaneously. Consequently, the opening o f the thumb and index finger, as indicated by a change in the voltage from zero to five volts, corresponded to the position of the lever arm at that point in time. Prior to the testing trials the target position was marked on the computer screen by typing the letter ' z ' . Kinaesthetic Testing Data. A sampling configuration with only one channel was constructed to record the data from the kinaesthetic testing trials. The single channel recorded and displayed the output from the potentiometer. Typing the letter ' z ' on the computer screen marked the target position for each set of kinaesthetic trials and a different letter from the alphabet marked the position of the lever arm on all of the replication trials. Kinaesthetic Training Data. A sampling configuration with one channel was constructed to collect and record the training data from the actively trained subjects. The single channel corresponded to the output from the potentiometer. Each target angle was marked on the computer screen by typing the letter ' z ' . In addition, the letter 'a ' , 'b ' , ' c ' , ' d ' , or 'e ' marked the position of all of the replication trials. A sampling configuration with three channels was constructed to collect all the training data for the passively trained subjects. Channel one recorded and displayed the output from the potentiometer. Channels two and three recorded and displayed the output from the E M G data for the biceps and triceps muscles. Each time a subject's arm was placed at a target angle the position was marked on the computer screen by typing the letter ' z ' . In addition, all of the passive replication trials were marked on the screen by typing the letter 'a ' , 'b ' , ' c ' , ' d ' , or 'e'. The E M G display was used only as a visual tool 44 to ensure that the biceps and triceps muscles of all of the subjects in this group were relaxed. Moving and Converting Data Coordination. A vertical cursor placed over the change in voltage of the current switch provided the position of the lever arm when the subject opened his thumb and index finger. The value in volts of the position of the lever arm was then copied and moved into an Excel file. Once the data was in Excel the voltage values were converted into degrees o f rotation for further analysis. Kinaesthetic Testing and Training. A vertical cursor placed over each letter provided the position of the lever arm after each angle replication trial. The voltage values from the lever arm position were copied and then pasted into an Excel file. Once the data was in an Excel file the values were converted into degrees of rotation for further analysis. Overall Procedure On the first day of testing all subjects read and signed an informed consent form and completed an activity questionnaire. In addition, subjects received verbal instructions regarding the procedures, and time commitment. The sequence of testing on the first day and for each subsequent day of testing was coordination of limb a, kinaesthetic testing of limb a, coordination testing of limb b, and kinaesthetic testing of limb b. The testing sequence between the two limbs varied between subjects to remove any ordering effects in the data, however the proximal angle was always tested before the distal angle. Control subjects returned within seven to ten days for a second testing session while the experimental subjects returned on the following Monday, for four 45 consecutive days of training of the right limb. In addition, subjects from the two training groups returned on the fifth consecutive day (Friday), for re-testing of both their right and left arm. Approximately one and three weeks following the post-training test all training subjects returned for re-testing. A l l testing sessions were approximately 45 minutes in length, while all training sessions were approximately 30 minutes in length. Statistical Analysis Two different measures were calculated to evaluate the performance for each subject. The two evaluation measures are the absolute constant error ( ICE) ) and the variable error (VE) . The absolute constant error measures the amount o f bias in responding without any indication to the direction of the bias (Schmidt 1988). Variable error is a measure of the inconsistency in responding or the variability o f a subject around his mean response (Schmidt 1988). The following two formulas were used to calculate the two performance measures: absolute constant error = |Z(x-T)/10| variable error = V[Z(x-ave)/10] where x = the subjects score on each trial T = the target for each set of scores ave = the average performance for each set o f scores The constant error, which measures the bias in responding including the direction of the bias as well as the variable error, which is a function of the constant error and the variable error were also examined. However, analysis of the constant and variable error did not contribute any additional information to the results so they are not discussed in this paper. 46 After training one would expect to see a decrease in both the absolute constant error and the variable error. A decrease in the absolute constant error would indicate that the bias in performance is closer to the target after training, while a decrease in the variable error would indicate that the consistency of performance is better on day two than on day one. Design This study employed a repeated measures design with one between subject factor and two within subject factors. The between subject factor is the group, consisting of a control (group one) and two training groups (groups two and three). The two within subject factors are day (day one and day two) and limb (right and left). For all calculations the significance level was set at alpha = 0.05. Analysis of Hypotheses Coordination. A repeated measures A N O V A was used to compare the changes between the three groups across the two days of testing. The analysis consisted of one between subject factor and two within subject factors. The between subject factor was the group (group one, group two and group three), while the two within subject factors were the day (testing day one and testing day two) and limb (right and left). Kinaesthesis. Same as coordination Training. A repeated measures A N O V A was employed to observe any significant differences between the two groups across the four days of training. The analysis consisted of one between subject factor and two within subject factors. The between subject factor was the group (group two and group three), while the within subject factors 47 were the day (training day one, training day two, training day three and training day four) and angle (proximal and distal). Retention. A repeated measures A N O V A was employed to determine i f there were any significant differences between the two training groups on the retention tests. The analysis consisted of one between subject factor and two within subject factors. The between subject factor was the group (group two and group three) while the within subject factors were the day (testing day two, testing day three, and testing day four) and limb (right and left). 4 8 Chapter III Results Group comparisons of kinaesthetic performance across the two days of testing A repeated measures A N O V A with one between subject factor and two within subject factors was used to compare the changes in performance from the pre and post-training sessions for the kinaesthetic condition and the coordination condition. The two conditions were analyzed separately. The between subject factor was the group (group one, group two and group three) while the within subject factors were the day (testing day one and testing day two) and the limb (right and left). For all calculations the significance level was set at alpha = 0.05 and this procedure was used to analyze the two performance measures ( |CE| and V E ) . The three-way A N O V A s yielded seven effects; Group (G), Day (D), Limb (L), G x D , G x L , D x L , and G x D x L . Unless otherwise specified, only the statistically significant effects are reported for each A N O V A . The first two hypotheses suggest that there is an improvement in performance on the second day of testing. The day by group interaction contrasts the changes in performance between day one and day two over the three groups. Consequently, the day by group interaction was used to analyze the first two hypotheses. This interaction determines the significance of the difference in performance from day one to day two between groups one, two and three. When this interaction is significant a test of simple main effects was performed to determine the significance of the changes in performance from day one to day two within each group. Error bars were not included in the graphs contained in the results section because the in some cases the error bars were so large that they would not fit on the graph. 49 However, the standard deviations for each of the mean values for all of the graphs are contained in the tables in appendix 'a ' that correspond to each graph. Analysis of Coordination Performance Absolute Constant Error Analysis Results from the A N O V A and the mean values for the main effects and interactions are listed in Tables l a through l h . The A N O V A results indicated that the day by group interaction was significant [F(2,18)=8.180, p=0.003]. The day by group interaction indicates that the difference in performance between day one and day two was not the same for groups one, two and three. The day by group interaction is illustrated in the following figure. Figure 4: Absolute constant error analysis of the day*group interaction for coordination Group one and group two display similar changes in the bias of their performance such that the performance bias moved closer to the target on day two. In contrast, the 50 performance bias of group three moved further away from the target on day two. A test of simple main effects did not reveal any significant changes in performance between day one and day two for group one, group two or group three. Although the change in performance between the three groups was significant, the change in performance within each group was not significant. Variable Error Analysis Results from the A N O V A and the mean values for all effects and interactions are listed in tables 2a through 2h. The A N O V A results did not reveal a significant day by group interaction [F(2,18)=2.036, p=0.160]. This result indicates that the difference in performance between day one and day two for group one, two and three were not significantly different from each other. The day by group interaction is illustrated in the following figure. Group 1 Group 2 Group 3 1 2 Day Figure 5: Variable error analysis of the day*group interaction for coordination 51 This graph shows that all three groups show the same trend in their performance and that the performance of all three groups demonstrated more consistency in their performance on day two than on day one. However, the changes within each group were not significant. Although the day by group interaction was not significant the A N O V A results revealed a significant day main effect. The consistency of performance on day one and day two was 5.6 and 4.7 degrees, respectively and this was significant at [F(l,18)=4.810, p=0.042]. This result indicates that the performance on day two, averaged over all other factors, was more consistent than the performance on day one. Analysis of Kinaesthetic Performance Absolute Constant Error Analysis Results from the A N O V A analysis and the mean values for the main effects and interactions are listed in tables 3a through 3h. The day by group interaction was not significant [F(2,18)=3.282, p=0.061] indicating that the difference in performance between day one to day two for groups one, two and three were not significantly different from each other. The mean values for the day by group interaction are represented in the figure below. 52 re > c re o E 0) 5 Q) 4 X3 • Group 1 — a — Group 2 Group 3 Day Figure 6: Absolute constant error analysis of the day*group interaction for kinaesthesis This graph demonstrates that the bias in performance moved further away from the target for group one and group three. In addition, this graph indicates that the performance bias of group two moved closer to the target on the second day of testing, however their change in performance was not significant. Variable Error Analysis Results from the A N O V A and the mean values are listed in tables 4a through 4h. The A N O V A results indicate that the day by group interaction was not significant [F(2,18)=0.329, p=.724] demonstrating that the difference in performance between day one and day two was not significantly different for groups one, two and three. The mean values for the day by group interaction are represented in the following figure. 53 • Group 1 —m— Group 2 Group 3 1 2 Day Figure 7: Variable error analysis of the day*group interaction for kinaesthesis This graph demonstrates that all three groups show almost no change in the consistency of their performance between day one and day two because the largest change in performance is only 0.3 degrees. Despite the non-significant day by group interaction the results from the A N O V A revealed a main limb effect [F(l,18)=8.761, p=0.008] indicating that the consistency in performance of the right and left limbs averaged over all other factors were different from each other. The mean consistency in performance of the right and left limb was 2.8 and 3.5 respectively. This result indicates that the performance of the right limb was more consistent than the performance of the left limb. Changes across the four days of Training A repeated measures A N O V A compared the changes in performance across the four days of training between group two and group three. The design consisted of one between subject factor and one within subject factor. The between subject factor was the group (group two and group three) while the between subject factor was the day (training day one, training day two, training day three and training day four). For all calculations 54 the significance level was set at alpha = 0.05 and this statistical procedure was used to analyze the two performance measures ( |CE| and V E ) . Absolute Constant Error Analysis Results from the A N O V A and the mean performance values are listed in tables 5a through 5d. Neither the day main effect [F(3,12)=1.595, p=0.228] nor the day by group interaction was significant [F(3,12)=2.443, p=0.124] indicating that averaged over the two groups there were no changes over the four days, and that this pattern was the same for each group. The day by group interaction is illustrated in the following figure. 1.4 .E 1.2 = g 1 ra >-> gVj.8 ra -° 0.6 0.4 -Group 2 -Group 3 2 3 Day Figure 8: Absolute constant error analysis of the day*group interaction for training This graph demonstrates that there is no trend in the changes in the performance bias across the four days of training for group two and group three. Variable Error Analysis Results from the A N O V A and the mean performance values are listed in tables 6a through 6d. Neither the day main effect [F(3,12)=2.312, p=0.120] nor the day by group 55 interaction was significant [F(3,12)=2.05, p=0.124] indicating that averaged over the two groups there were no changes over the four days, and that this pattern was the same for each group. The day by group interaction is illustrated in the following figure. — G r o u p 2 —a—Group 3 Figure 9: Variable error analysis of the day*group interaction of the training This figure illustrates that the consistency in performance of group two and group three shows almost no change across the four days of training. In addition, the mean consistency in performance of groups two and group three averaged over the four days was 2.62 and 2.14 degrees, respectively. This was significant at [F( 1,12)= 10.814, p=0.006]. This indicates that the performance of group three was more consistent than the performance of group two. Retention A repeated measures A N O V A was used to examine the retention of any improvements in performance on the proprioception and the coordination tasks both one and three weeks following training. The design consisted on one between subject factor and two within subject factors. The retention of the kinaesthetic performance and the 56 coordination performance were analyzed separately. The between subject factor was the group (group two and group three) while the within subject factors were the day (testing day two, testing day three and testing day four) and the limb (right and left). This statistical procedure was used to analyze the two performance measures ( |CE| and V E ) . Only groups two and three participated in the four days of training, therefore only these two groups were used for this analysis. A s this analysis examines the retention of performance only the interactions regarding group performance across the three days of testing w i l l be discussed. Retention of Coordination Performance Absolute Constant Error Analysis Results from the A N O V A and the mean values for the effects and interactions are listed in tables 7a through 7h. The day by group interaction was not significant [F(l,18)=2.271, p=0.149]. This result indicates that the difference between day two, day three and day four were not significantly different for group two and group three. The day by group interaction is illustrated in the following figure. 57 ••—Group 2 •—Group 3 1 2 3 Day Figure 10: Absolute constant error analysis of the day*group interaction for the retention of coordination This figure demonstrates that for these subjects the bias in performance for group two shows almost no change on the two retention tests while the bias in performance for group three was closer to the target on the first retention test than on the post-training test. The bias in performance for group three shows almost no change on the second retention test when compared to the first retention test. However, these differences were of insufficient magnitude (p=0.15) to be able to generalize beyond the sample. Variable Error Analysis Results from the A N O V A and the mean values for the effects and interactions are listed in tables 8a through 8h. The day by group interaction was not significant [F(l,18)=0.672, p=0.530]. This result indicates that the difference between day two, day three and day four was not significantly different for group two and group three. The day by group interaction is illustrated in the following figure. 58 —•—Group 2 —©—Group 3 1 2 3 Day Figure 11: Variable error analysis of the day*group interaction for the retention of coordination This graph demonstrates that there is almost no change in the consistency of performance between day two, day three and day four for group two and group three. Retention of Kinaesthetic Performance Absolute Constant Error Analysis Results from the A N O V A and the mean values for the effects and interactions are listed in tables 9a through 9h. The day by group interaction was not significant [F(l,12)=0.965, p=0.378]. This result indicates that the difference in the performance bias between day two, day three and day four was not significantly different for group two and group three. The day by group interaction is illustrated in the following figure. 59 Figure 12: Absolute constant error analysis of the day*group interaction of the retention of kinaesthesis This graph indicates that group two and group three show almost no change in the bias of their performance on the two retention tests. Variable Error Analysis Results from the A N O V A and the mean values for the effects and interactions are listed in tables 10a through lOh. The day by group interaction was not significant [F(l,18)=0.027, p-0.973]. This result indicates that the difference between day two, day three and day four was not significantly different for group two and group three. The day by group interaction is illustrated in the following figure. 60 Figure 13: Variable error analysis of the day*group interaction of the retention of kinaesthesis This figure illustrates that there is almost no change in the consistency of performance from day two, day three and day four for group two and group three. Type I E r r o r A type I error occurs when the results show a significant effect or interaction in the sample when no differences exist in the population. The probability of having a type I error is calculated using the significance level and the total number of tests used in the analysis. The following formula was used to calculate the probability of making a type I error in this analysis: Error = l - ( l - a ) A k Where a = significance level (0.05) k = the total number of all tests For this experiment the total number of tests was 52, therefore the probability of making a type I error was 93%. Consequently, the large number of tests lead to a high probability of making a type I error. 61 Chapter IV Discussion Subject Allocation Subjects were randomly assigned to the three groups, however subjects who could only participate for two days were automatically placed in the control group. In addition, four of the subjects who participated in this study were national or varsity athletes. It was previously mentioned that athletes may have a greater kinaesthetic acuity than non-athletes. Consequently, the inclusion of these four athletes may have biased the results. As a result of the random subject allocation there was one athlete in the control group, one athlete in the actively trained group and two athletes in the passively trained group. Accordingly, the athletes were distributed throughout the three groups. In addition, the removal of each athlete from their respective groups did not cause any noticeable changes in the average performance values for each group, indicating that the inclusion of the athletes did not skew the data. Velocity of Movement Before testing began subjects were trained to move their limb at a velocity between 45 and 55 degrees per second. The testing protocol used in this experiment only permitted subjective monitoring of the velocity of movement for each subject during the testing and training sessions. Analysis of the speed of movement from the data files reveals that the speed of movement actually ranged between 40 and 55 degrees per second during the testing sessions and during the active and passive training sessions. 62 Changes in Performance on the Coordination Task The A N O V A results revealed a significant day by group interaction for the absolute constant error analysis of coordination. The mean values indicated that the bias in performance was closer to the target on the post-training test for group one and group two. In contrast, the bias in performance was further away from the target on the post-training test for group three. Group one did not participate in proprioceptive training, therefore the change in the performance bias of this group is probably the result of familiarity with the task on the second day of testing. Group two participated in active kinaesthetic training, however the change in the bias of performance is less than the change of group one, the control group. Consequently, the change in the performance bias of group two cannot be attributed to the kinaesthetic training. Similar to group one the change in the performance bias demonstrated by group two is probably the result of familiarity with the task on the second day of testing. Despite a significant day by group interaction the changes within each group were not significant. These results suggest that both the active and the passive kinaesthetic training did not improve the performance bias on the coordination task. In addition, the A N O V A results did not reveal a significant day by group interaction for the variable error analysis of coordination. The mean values indicate that there is more consistency in performance on day two than on day one for group one and group two, while there is almost no change in the consistency of performance for group three. Although group one and group two show more consistency in their performance on day two, the changes in performance were not significant. Consequently, these changes are probably the result of familiarity with the task on the second day of testing. 63 These results suggest that both active and passive kinaesthetic training do not improve the consistency of performance on the coordination task. Possible explanations for the lack of improvement in the bias of performance and the consistency of performance for group two and group three include the movement speed and various aspects of the training protocol. Several sources suggest that some movements, especially fast movements, do not use sensory information (Kottke 1978 and Leonard 1998, p208). The task for this experiment was similar to throwing a Frisbee and it was used in this experiment because Cordo (1990) demonstrated that subjects use their kinaesthetic acuity when performing this task at 22 degrees per second. In the present experiment the speed of movement ranged between 40 and 55 degrees per second and the faster movement speed may have prevented subjects from using sensory information to perform the coordination task. When performing slow movements (22 degrees per second or less) subjects may be able to use sensory feedback during the movement (Cordo 1990), however at faster movement speeds subjects may only be able to use sensory feedback as a post-response mechanism. If the movement speed used in this experiment prevented subjects from using sensory information to perform the coordination task then improving one's kinaesthetic awareness would not have improved their performance on the task. Various aspects of the training may also explain the lack of improvement on the coordination task. Both the amount of training and the intensity of the training may not have been sufficient to improve coordination. In addition, the benefits from the training protocol may not carryover into the coordination task used in this experiment. During the four days of training subjects practiced replicating a target position with the target as the 64 endpoint of the movement. However, performance on the coordination task required subjects to identify the target position while their limb moved through the target, rather than indicating the target at the end of the movement. Consequently, the benefits of this training protocol may only be evident on a coordination task that is a series of endpoints such as slicing a loaf of bread (Sainburg et al 1993). Changes in Performance on the Kinaesthesis Task The A N O V A results did not reveal a significant day by group interaction for the absolute constant error analysis. The mean values indicate that the bias in performance of group one and group three is further away from the target on the post-training test, while the performance bias is closer to the target on day two than on day one for group two. Although the change in the bias of performance for group two was not significant, there are several possible explanations underlying the change in their performance. For example, cortical plasticity is one possible mechanism underlying the change in performance of group two after training. Cortical plasticity occurs in many areas of the brain including the sensory, sensorimotor and motor cortices (Leonard 1998, p210 and 219). The cortex contains receptive fields or maps that represent different parts of the body such that stimulation of the cortical map evokes movement (motor cortex) or sensation (sensory cortex) of the corresponding limb. However, the size of these cortical maps is susceptible to change with activity (Jenkins et al 1990 and Nudo et al 1996). Accordingly the size of the sensory, sensorimotor and motor cortices representing the right limb could have expanded across the four days of training thereby improving performance on the kinaesthetic task on the second day of testing (Kaas 1991). Another 65 possible mechanism underlying the change in performance on the kinaesthetic task is that group two improved the feed-forward system of the cerebellum. The cerebellum receives afferent information from the somatosensory receptors as well as the motor commands originating from the cortex allowing the cerebellum to act as a comparator as it "compares the actual movement being performed to the movement desired by the brain" (Leonard 1998 p.50). In addition, the cerebellum is a feed-forward system that contributes to the motor programming of voluntary movement (Leonard 1998 p.50). During the training sessions group two performed a series of active angle replications. After each replication the cerebellum received afferent information from the sensory receptors as well as the motor commands associated with the movement. However, at the end of each replication the experimenter moved each subject's limb to the correct target angle thereby providing subjects with the error of their movement. The external feedback provided by the experimenter may have also provided the cerebellum with an additional source of afferent information that could be compared to the motor command originating from the cortex. Over the four days of training the cerebellum may have improved the accuracy of its feed-forward system as a result of the repeated comparisons between the sensory information that was available after the movement and after the corrected movement with the motor command used to produce the movement. Overall, the lack of a significant day by group interaction suggests that both active and passive kinaesthetic training do not improve the bias in performance on the acuity task. In addition, the A N O V A results did not reveal a significant day by group interaction for the variable error analysis of kinaesthesis. The mean values indicate that all three groups show almost no change iri the consistency of their performance between 66 day one and day two. These results suggest that both active and passive kinaesthetic training do not improve the consistency of performance on the kinaesthetic acuity task. Additional analysis indicates that the amount and extent of the improvement on the kinaesthetic task varied between subjects such that the subjects with poor initial performance demonstrated the greatest changes in performance after training. For example, subject ' a ' with a baseline performance of 20 degrees had a post-training performance of 4 degrees, while subject 'b ' with a baseline performance of 7 degrees had a post-training performance of 5 degrees. The different extents of change in performance across subjects in group two suggest that some subjects are more susceptible to the mechanisms underlying the changes in performance (Birmingham et al 1998). Changes in the Performance of the Trained and Untrained Limb Results from the A N O V A s did not reveal any significant limb by day by group interactions suggesting that the changes in performance of the right and left limb were not different from each other. These results suggest that active and passive kinaesthetic training do not improve the performance bias or the consistency in performance of the trained and the untrained limb on either the coordination or the kinaesthetic task. Coordination Theories Although the performance on the coordination task did not improve after training, the schema theory of coordination underlies the basis of the training protocol used in this experiment. The schema theory consists of the recall and the recognition schema. The recall schema, concerned with the production of movement, develops a relationship 67 between the outcome of the movement and the past parameters used to create this outcome. The recognition schema, concerned with response evaluation, develops a relationship between movement outcomes, the initial conditions and the sensory consequences produced by these combinations (Schmidt 1988, p484-486). On each day of testing the initial conditions and the sensory consequences were available to each subject. On each day of training the initial conditions, the sensory consequences and the outcome of the movement were available to each of the trained subjects. Consequently, over the four days of training subjects may have used the recognition schema to evaluate their movement and then use this evaluation to improve the recall schema which is concerned with the production of their movement. L i m b Effect The main limb effect only occurred in the variable error analysis of the kinaesthetic task. The limb effect indicates that the performance of the right limb was more consistent than the performance of the left limb on the kinaesthetic task. A l l of the subjects that participated in this study are right hand dominant. Consequently, the limb effect is probably the result of the limb dominance of all subjects. D a y Effect The main day effect only occurred in the variable error analysis of the coordination task. The day effect indicates that there is more consistency in performance on the post-training test than on the pre-training test. The day effect only occurred in the variable error analysis of coordination and not in the absolute constant error analysis of 68 coordination. Accordingly, one might suggest that changes in performance appear in the consistency of performance before appearing in the bias of performance. Group comparisons across the four days of training The A N O V A results only reveal a group effect for the variable error analysis of the four days of training. The group effect indicates that the performance of group three is more consistent than the performance of group two. The active training of group two involves feedback from muscle, skin and joint receptors in addition to the motor program and the sense of effort associated with the movement. The passive training of group three only involves feedback from muscle, joint and skin receptors. Consequently, subjects from the active group may produce more errors in their movement because these subjects need to resolve more factors during training. The additional factors involved in the active movement could be providing conflicting information regarding the position of the limb, leading to uncertainty about the limb's position in relation to the target and leading to an error in performance. Another possible explanation for the larger performance errors among group two than among group three is the attenuation of sensory information associated with active movement. Both Birmingham et al (2000) and Collins et al (1998) provided results implying that sensory information is attenuated during active movement. Attenuation of the sensory feedback would create uncertainty about the movement leading to a larger error in performance during active movement. The sensory afferents are also attenuated during passive movements but not to the same extent as during active movement (Collins et al 1998). Therefore, the passively trained subjects are closer to the 69 target than the actively trained subjects because their sensory feedback shows less attenuation. Changes at the Receptor Level as a Result of Training A s previously mentioned there are three receptors that contribute to kinaesthesia, joint, skin and muscle. Afferent information from the joint receptors code for limb position at the end or near the extremes of joint movement. The afferent information from skin receptors is important in providing kinaesthetic acuity of the hand and extremities. In contrast to the skin and joint afferents, information from the muscle afferents faithfully code limb position throughout the joint range of motion. During this experiment subjects were trained to reproduce elbow joint angles. The joint angles used in this experiment were within the midrange of limb movement, therefore the joint receptors were probably not trained over the four days of training. In addition, this experiment used elbow joint angles and the elbow jo in is not considered an extremity, therefore the skin afferents were probably not trained during the four days of training. Consequently, any changes at the receptor level would probably be attributed to the muscle spindle as the spindle codes the entire range of motion at all joints. Retention Clinical ly it is important to know the long-term effects of training. For example, i f a physiotherapist spends five hours one week improving a patient's mobility, the physiotherapist would want to know the retention of any improvements attained during the week. Therefore, the final aim of this experiment was to demonstrate the extent of 70 the retention of improvement among group two and three. The A N O V A results did not reveal any retention of performance on the coordination or kinaesthetic tasks. The lack of retention suggests that the mechanisms responsible for the changes in the bias and the consistency of performance are short-term and transient. Cortical plasticity was previously mentioned as a mechanism that changed performance. Plasticity implies that the representation of the cortex changes with activity and decreases with inactivity (Nudo et al 1996 and Kaas 1991). The loss of the change in performance supports cortical plasticity as the mechanism underlying the change in performance because the area representing the right limb would have expanded during training thereby improving performance on the post-training session. However, when the subjects ceased training the representation of the limb would have decreased, leading to a decline in performance on the retention tests. Conclusions The results from this experiment imply that unilateral kinaesthetic training does not improve coordination of the trained and untrained limb. The results also imply that both active and passive unilateral training does not improve kinaesthetic awareness of the trained and untrained limb. Furthermore, the effects of training are transient as evidenced by the lack of retention on the one and three week retention tests. In addition, this experiment supports the hypothesis that active movements attenuate afferent sensory information. While several mechanisms underlying the changes in performance are outlined in the discussion, the particular mechanisms remain unanswered. 71 Sources of Error Sources of error in this experiment exist in both the equipment and the procedure. During this experiment a blindfold prevented subjects from using any visual information during the experiment. After removing the blindfold on each day of testing or training several subjects reported feeling sleepy. Consequently, there may have been changes in the motivation level of each subject as a result of wearing the blindfold. Future experiments should consider alternate methods of removing visual information in order to prevent fluctuations in each subject's level of motivation. In addition, each subject's posture remained constant during the testing and training sessions, however subjects did not necessarily sit in the exact same position on subsequent days of testing or training. While the chair that subjects sat in was always placed in the same position with respect to the manipulandum, subjects may have sat in a slightly different position for each session. Lastly, the repositioning of the limb over the target is another source of error. Over the testing sessions and especially over the four days of training, each subject's limb was repeatedly repositioned over the target angles. Repositioning of the limb was performed manually using a plum line that extended from the end of the manipulandum to the protractor at the bottom of the manipulandum. Consequently, the limb was not positioned in the exact same position each time. Future experiments should consider alternate methods that would provide precise reposition of the limb at each target. A n additional limitation of this experiment may exist in the allocation of subjects into the three groups. Before testing began subjects were randomly assigned to one of the three groups and subjects who could only participate for two days were automatically 72 placed in the control group. Consequently, the baseline values of each group may not have been similar across the performance measures. To remove any bias in the baseline data between the three groups, subjects could be allocated to one of the groups based on their baseline performance. This method of subject allocation would ensure that all three groups displayed similar performance values on the first day of testing. Future Considerations Kinaesthetic training is a new area of research that has many potential benefits for sports and rehabilitation settings, however the potential benefits of kinaesthetic training remain unanswered. The present experiment attempted to explore the potential benefits of kinaesthetic training on one's coordination. While the results did not demonstrate any significant change in coordination, subjects from the active training group improved their kinaesthetic awareness on the post-training session. In addition, the results indicate that subjects do not retain their improved performance one and three weeks following training. Although this experiment did not improve one's coordination, additional experiments using a different coordination task or an alternate training protocol might provide contrasting results. For example, future experiments could modify the training protocol of the present experiment to improve the effectiveness of the training; potential modifications include the amount and intensity of the training. Findings from any future studies could be compared to the results from the present experiment to determine the effectiveness of any changes in the protocol. In addition, future experiments should consider including subject populations with a decreased sense of kinaesthetic awareness in comparison to adults. Populations that 73 have a lower sense of kinaesthetic awareness than adults include children and the elderly. A s presented in the discussion subjects with poor initial performance demonstrated the largest improvements; therefore it may be speculated that children and the elderly would demonstrate the greatest benefits from kinaesthetic training. Furthermore, additional experiments could examine the effects of kinaesthetic training on a variety of coordination tasks. Additional tasks could include handwriting ability, slicing a loaf of bread, buttoning one's shirt and bringing a fork to one's mouth. Future experiments could also examine the effects of training on sports related tasks such as throwing a dart and performing a tennis serve. 74 References A L L E G R U C C I M . , W H I T N E Y S. L . , L E P H A R T S. 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Journal of Neurophsyiology 67(5): 1114-1122, 1992. 79 Appendix A Source df F value Sig-Between Subjects Group 2 0.902 0.423 Within Subjects Limb 1 1.288 0.271 L imb* Group 2 1.350 0.284 Day 1 0.077 0.785 Day* Group 2 8.180 0.003 Limb*Day 1 1.532 0.232 Limb*Day*Group 2 0.056 0.945 Table la: A N O V A results for the |CE | analysis of coordination Group Mean 1 7.2 2 6.0 3 6.3 Table lb: Mean performance values for each group for the |CE | analysis of coordination Limb Mean Right 7.0 Left 6.1 Table lc: Mean performance values for each limb for the |CE | analysis of coordination Day Mean 1 6.6 2 6.5 Table Id: Mean performance values for each day for the |CE | analysis of coordination 80 Group Limb Mean 1 Right 8.6 Left 5.9 2 Right 6.1 Left 5.9 3 Right 6.2 Left 6.5 Table le: Mean performance values for the group*limb interaction for the |CE | analysis of coordination Group Day Mean SD 1 1 8.4 1.81 2 6.0 1.44 2 1 6.4 1.73 2 5.6 1.89 3 1 5.0 2.35 2 7.7 2.46 Table If: Mean performance va ues and standard deviations for the group*day interaction for the |CE | analysis of coordination Limb Day Mean Right 1 6.6 2 7.4 Left 1 6.6 2 5.5 Table l g : Mean performance values for the limb*day interaction for the |CE | analysis of coordination 81 Group Limb Day Mean 1 Right 1 9.1 2 8.0 Left 1 7.7 2 4.1 2 Right 1 6.2 2 6.0 Left 1 6.6 2 5.2 3 Right 1 4.3 2 8.1 Left 1 5.6 2 7.3 Table l h : Mean performance values of the group*limb*day interaction for the |CE | analysis of coordination Source df F value Sig. Between Subjects Group 2 2.316 0.127 Within Subjects Limb 1 0.157 0.696 Limb* Group 2 0.663 0.527 Day 1 4.810 0.042 Day* Group 2 2.036 0.160 Limb*Day 1 0.069 0.796 Limb*Day*Group 2 0.226 0.800 Table 2a: A N O V A results for the V E analysis of coordination Group Mean 1 6.2 2 4.7 3 5.0 Table 2b: Mean performance values for each group for the V E analysis of coordination Limb Mean Right 5.2 Left 5.4 Table 2c: Mean performance values for each limb for the V E analysis of coordination 82 Day Mean 1 6.0 2 4.7 Table 2d: Mean performance values for each day for the V E analysis of coordination Group Limb Mean 1 Right 6.5 Left 6.0 2 Right 4.3 Left 5.1 3 Right 4.9 Left 5.1 Table 2e: Mean performance values for the group*limb interaction for the V E analysis of coordination Group Day Mean SD 1 1 7.7 3.52 2 4.8 0.76 2 1 5.1 1.26 2 4.3 1.06 3 1 5.1 1.49 2 5.0 1.17 Table 2f: Mean performance va ues and standard deviations for the group*day interaction for the V E analysis of coordination Limb Day Mean Right 1 5.9 2 4.5 Left 1 6.0 2 4.9 Table 2g: Mean performance values for the limb*day interaction for the V E analysis of coordination 83 Group Limb Day Mean 1 Right 1 8.2 2 4.8 Left 1 7.2 2 4.9 2 Right 1. 4.5 2 4.0 Left 1 5.7 2 4.6 3 Right 1 5.1 2 4.8 Left 1 5.1 2 5.2 Table 2h: Mean performance values of the group*limb*day interaction for the V E analysis of coordination Source df F value Sig. Between Subjects Group 2 0.602 0.558 Within Subjects L imb 1 0.217 0.647 L imb* Group 2 1.332 0.289 Day 1 0.885 0.359 Day*Group 2 3.282 0.061 Limb*Day 1 0.899 0.356 Limb*Day*Group 2 2.1816 0.086 Table 3a: A N O V A results for the |CE | analysis of kinaesthesis Group Mean 1 5.7 2 4.6 3 4.6 Table 3b: Mean performance values for each group for the |CE | analysis of kinaesthesis Limb Mean Right 5.1 Left 4.9 Table 3c: Mean performance values for each limb for the |CE | analysis of kinaesthesis 84 Day Mean 1 5.3 2 4.7 Table 3d: Mean performance values for each day for the |CE | analysis of kinaesthesis Group Limb Mean 1 Right 5.9 Left 5.6 2 Right 5.3 Left 3.9 3 Right 4.2 Left 5.1 Table 3e: Mean performance values for the group*limb interaction for the |CE | analysis of kinaesthesis Group Day Mean SD 1 1 5.6 3.1 2 5.9 3.4 2 1 6.1 3.1 2 3.2 1.1 3 1 4.2 1.6 2 5.0 1.3 Table 3f: Mean performance values and standard deviations for the group*day interaction for the |CE | analysis of kinaesthesis Limb Day Mean Right 1 5.6 2 4.6 Left 1 5.0 2 4.8 Table 3g: Mean performance values for the limb*day interaction for the |CE | analysis of kinaesthesis 85 Group Limb Day Mean 1 Right 1 6.3 2 5.5 Left 1 4.9 2 6.3 2 Right 1 7.3 2 3.3 Left 1 4.9 2 3.0 3 Right 1 3.3 2 5.1 Left 1 5.2 2 5.0 Table 3 h : Mean performance values of the group*limb*day interaction for the |CE | analysis of kinaesthesis Source df F value Sig. Between Subjects Group 2 0.274 0.764 Within Subjects Limb 1 8.761 0.008 Limb* Group 2 0.732 0.495 Day 1 0.096 0.760 Day* Group 2 0.329 0.724 Limb*Day 1 0.103 0.752 Limb*Day*Group 2 0.061 0.941 Table 4a: A N O V A results for the V E analysis of kinaesthesis Group Mean 1 3.2 2 3.0 3 3.3 Table 4b: Mean performance values for each group for the V E analysis of kinaesthesis Limb Mean Right 2.8 Left 3.5 t Table 4c: Mean performance values for each limb for the V E analysis of kinaesthesis 86 Day Mean 1 3.1 2 3.2 Table 4d: Mean performance values for each day for the V E analysis of kinaesthesis Group Limb Mean 1 Right 2.9 Left 3.4 2 Right 2.8 Left 3.2 3 Right 2.7 Left 3.8 Table 4e: Mean performance values for the group*limb interaction for the V E analysis of kinaesthesis Group Day Mean SD 1 1 3.1 0.43 2 3.2 1.07 2 1 3.1 0.74 2 2.9 0.55 3 1 3.1 1.05 2 3.4 1.04 Table 4f: Mean performance va ues and standard deviations for the group*day interaction for the V E analysis of kinaesthesis Limb Day Mean Right 1 2.8 2 2.8 Left 1 3.4 2 3.6 Table 4g: Mean performance values for the limb*day interaction for the V E analysis of kinaesthesis 87 Group Limb Day Mean 1 Right 1 2.9 2 2.9 Left 1 3.3 2 3.5 2 Right 1 2.9 2 2.7 Left 1 3.4 2 3.1 3 Right 1 2.6 2 2.8 Left 1 3.5 2 4.1 Table 4h: Mean performance values of the group*limb*day interaction for the V E analysis of kinaesthesis Source df F value Sig. Between Subjects Group 1 2.755 0.123 Within Subjects Day 1 1.595 0.228 Day*Group 1 1.421 0.262 Table 5a: A N O V A results for the |CE | analysis of training Group Mean 2 1.1 3 0.8 Table 5b: Group means for the |CE | analysis of training Day Mean 1 1.0 2 0.8 3 0.9 4 1.2 Table 5c: Day means for the |CE | analysis of training Group Day Mean SD 2 1 1.3 0.78 2 0.8 0.42 3 1.1 0.41 4 1.3 0.49 3 1 0.7 0.39 2 0.9 0.31 3 0.7 0.28 4 1.0 0.49 Table 5d: Mean values for the day*group interaction for the |CE | analysis of training Source df F value Sig. Between Subjects Group 1 10.814 0.006 Within Subjects Day 1 2.312 0.120 Day* Group 1 2.050 0.151 Table 6a: A N O V A results for the V E analysis of training Group Mean 2 2.6 3 2.1 Table 6b: Group means for the V E analysis of training Day Mean 1 2.3 2 2.4 3 2.2 4 2.5 Table 6c: Day means for the V E analysis of training 89 Group Day Mean SD 2 1 2.5 0.78 2 2.7 0.42 3 2.4 0.41 4 3.0 0.49 3 1 2.1 0.39 2 2.2 0.31 3 2.1 0.28 4 2.1 0.49 Table 6d: Mean values for the day*group interaction for the V E analysis of training Source df F value Sig. Between Subjects Group 1 1.030 0.330 Within Subjects Limb 1 0.131 0.724 Limb*Group 2 0.171 0.686 Day 1 3.294 0.076 Day*Group 2 2.271 0.149 Limb*Day 1 0.117 0.890 Limb*Day*Group 2 0.220 0.806 Table 7a: A N O V A results for the |CE | analysis of the retention of coordination Group Mean 2 5.4 3 6.2 Table 7b: Mean performance values for each group for the |CE | analysis of the retention of coordination Limb Mean Right 5.9 Left 5.8 Table 7c: Mean performance values for each limb for the |CE | analysis of coordination 90 Day Mean 2 6.7 3 5.3 4 5.5 Table Id: Mean performance values for each day for the |CE | analysis of the retention of coordination Group Limb Mean 2 Right 5.6 Left 5.3 3 Right 6.2 Left 6.3 Table 7e: Mean performance values for the group*limb interaction for the |CE | analysis of the retention of coordination Group Day Mean SD 2 2 5.6 1.89 3 4.8 2.00 4 5.9 1.95 3 2 7.7 2.46 3 5.8 1.63 4 5.2 0.37 Table 7f: Mean performance va ues and standard deviations for the group*day interaction for the |CE | analysis of the retention of coordination Limb Day Mean Right 2 7.1 3 5.3 4 5.4 Left 2 6.2 3 5.4 4 5.6 Table 7g: Mean performance values for the limb*day interaction for the |CE | analysis of the retention of coordination 91 Group Limb Day Mean 2 Right 2 6.0 3 4.7 4 6.1 Left 2 5.2 3 4.9 4 5.6 3 Right 2 8.1 3 5.9 4 4.7 Left 2 7.3 3 5.8 4 5.7 Table 7h: Mean performance values of the group*limb*day interaction for the |CE| analysis of the retention of coordination Source df F value Sig. Between Subjects Group 1 0.833 0.379 Within Subjects L imb 1 0.263 0.617 Limb*Group 2 0.295 0.597 Day 1 0.445 0.652 Day* Group 2 0.672 0.530 Limb*Day 1 1.111 0.364 Limb*Day*Group 2 0.373 0.697 Table 8a: A N O V A results for the V E analysis of the retention of coordination Group Mean 2 4.5 3 4.9 Table 8b: Mean performance values for each group for the V E analysis of the retention of coordination Limb Mean Right 4.8 Left 4.6 Table 8c: Mean performance values for each limb for the V E analysis of coordination 92 Day Mean 2 4.6 3 4.9 4 4.6 Table 8d: Mean performance values for each day for the V E analysis of the retention of coordination Group Limb Mean 2 Right 4.6 Left 4.3 3 Right 4.9 Left 4.9 Table 8e: Mean performance values for the group*limb interaction for the V E analysis of the retention of coordination Group Day Mean SD 2 2 4.3 1.06 3 4.9 0.96 4 4.2 1.33 3 2 5.0 1.17 3 4.9 0.74 4 5.0 2.02 Table 8f: Mean performance va ues and standard deviations for the group*day interaction for the V E analysis of the retention of coordination Limb Day Mean Right 2 4.4 3 5.1 4 4.8 Left 2 4.9 3 4.6 4 4.3 Table 8g: Mean performance values for the limb*day interaction for the V E analysis of the retention of coordination 93 Group Limb Day Mean 2 Right 2 4.0 3 5.4 4 4.4 Left 2 4.8 3 4.4 4 3.9 3 Right 2 4.8 3 4.9 4 5.1 Left 2 5.2 3 4.9 4 4.8 Table 8h: Mean performance values of the group*limb*day interaction for the V E analysis of the retention of coordination Source df F value Sig-Between Subjects Group 1 5.269 0.041 Within Subjects Limb 1 0.063 0.806 Limb* Group 2 0.494 0.496 Day 1 0.118 0.737 Day*Group 2 0.965 0.345 Limb*Day 1 0.228 0.641 Limb*Day*Group 2 1.936 0.189 Table 9a: A N O V A results for the |CE | analysis of the retention of kinaesthesis Group Mean 2 3.7 3 4.8 Table 9b: Mean performance values for each group for the | C E | analysis of the retention of kinaesthesis Limb Mean Right 4.3 Left 4.1 Table 9c: Mean performance values for each limb for the |CE | analysis of kinaesthesis 94 Day Mean 2 4.1 3 4.7 4 3.9 Table 9d: Mean performance values for each day for the |CE | analysis of the retention of kinaesthesis Group Limb Mean 2 Right 3.5 Left 3.8 3 Right 5.1 Left 4.4 Table 9e: Mean performance values for the group*limb interaction for the |CE | analysis of the retention of kinaesthesis Group Day Mean SD 2 2 3.2 1.11 3 4.3 1.18 4 3.5 1.17 3 2 5.0 1.33 3 5.1 1.69 4 4.3 1.94 Table 9f: Mean performance values and standard deviations for the group*day interaction for the |CE | analysis of the retention of kinaesthesis L imb Day Mean Right 2 4.2 3 5.0 4 3.8 Left 2 4.0 3 4.4 4 4.0 Table 9g: Mean performance values for the limb*day interaction for the |CE | analysis of the retention of kinaesthesis 95 Group Limb Day Mean 2 Right 2 3.3 3 4.3 4 2.8 Left 2 3.0 3 4.3 4 4.2 3 Right 2 5.1 3 5.6 4 4.7 Left 2 5.0 3 4.5 4 3.8 Table 9h: Mean performance values of the group*limb*day interaction for the |CE | analysis of the retention of kinaesthesis Source df F value Sig. Between Subjects Group 1 3.636 0.081 Within Subjects L imb 1 5.164 0.042 L imb* Group 2 0.074 0.790 Day 1 0.329 0.723 Day*Group 2 0.027 0.973 Limb*Day 1 0.955 0.399 Limb*Day*Group 2 0.971 0.393 Table 10a: A N O V A results for the V E analysis of the retention of kinaesthesis Group Mean 2 2.8 3 3.5 Table 10b: Mean performance values for each group for the V E analysis of the retention of kinaesthesis Limb Mean Right 2.9 Left 3.4 Table 10c: Mean performance values for each limb for the V E analysis of kinaesthesis 96 Day Mean 2 3.2 3 3.3 4 3.0 Table lOd: Mean performance values for each day for the V E analysis of the retention of kinaesthesis Group Limb Mean 2 Right 2.6 Left 3.1 3 Right 3.2 Left 3.8 Table lOe: Mean performance values for the group*limb interaction for the V E analysis of the retention of kinaesthesis Group Day Mean SD 2 2 2.9 0.55 3 2.9 0.66 4 2.7 0.67 3 2 3.4 1.04 3 3.6 0.93 4 3.3 1.06 Table lOf: Mean performance values and standard deviations for the group*day interaction for the V E analysis of the retention of kinaesthesis Limb Day Mean Right 2 2.7 3 3.0 4 3.0 Left 2 3.6 3 3.6 4 3.1 Table lOg: Mean performance values for the limb*day interaction for the V E analysis of the retention of kinaesthesis 97 Group Limb Day Mean 2 Right 2 2.7 3 2.5 4 2.7 Left 2 3.1 3 3.4 4 2.7 3 Right 2 2.8 3 3.5 4 3.2 Left 2 4.1 3 3.7 4 3.5 Table lOh: Mean performance values of the group*limb*day interaction for the V E analysis of the retention of kinaesthesis 98 Appendix B Subject Movement Correlation Matrix for C E analysis KR1 KR2 KL1 KL2 CR1 CR2 CL1 CL2 KR1 Pearson 1.000 Sig. N 21 KR2 Pearson 0.156 1.000 Sig. 0.249 N 21 21 KL1 Pearson 0.450 0.146 1.000 Sig. 0.020 0.263 N 21 21 21 KL2 Pearson 0.127 0.504 0.473 1.000 Sig. 0.292 0.010 0.015 N 21 21 21 21 CR1 Pearson -0.017 -0.220 -0.111 -0.107 1.000 Sig. 0.471 0.169 0.316 0.322 N 21 21 21 21 21 CR2 Pearson -0.018 0.451 0.412 0.653 0.122 1.000 Sig. 0.470 0.020 0.032 0.001 0.299 N 21 21 21 21 21 21 CL1 Pearson 0.431 0.313 -0.041 0.142 -0.016 0.035 1.000 Sig. 0.026 0.083 0.430 0.269 0.472 0.440 N 21 21 21 21 21 21 21 CL2 Pearson 0.078 0.072 0.011 -0.352 0.001 -0.117 0.026 1.000 Sig. 0.368 0.377 0.481 0.059 0.499 0.306 0.455 N 21 21 21 21 21 21 21 21 101 Correlation Matrix for V E analysis KR1 KR2 KL1 KL2 CR1 CR2 CL1 CL2 KR1 Pearson 1.000 Sig. N 21 KR2 Pearson 0.177 1.000 Sig. 0.221 N 21 21 KL1 Pearson 0.337 -0.033 1.000 Sig. 0.068 0.443 N 21 21 21 KL2 Pearson -0.091 0.173 -0.173 1.000 Sig. 0.348 0.227 0.227 N 21 21 21 21 CR1 Pearson -0.100 -0.231 -0.048 0.033 1.000 Sig. 0.333 0.157 0.418 0.443 N 21 21 21 21 21 CR2 Pearson 0.329 -0.071 0.528 -0.039 -0.005 1.000 Sig. 0.073 0.380 0.007 0.434 0.491 N 21 21 21 21 21 21 CL1 Pearson 0.112 -0.133 0.269 -0.188 0.363 0.495 1.000 Sig. 0.315 0.283 0.119 0.207 0.053 0.011 N 21 21 21 21 21 21 21 CL2 Pearson 0.097 0.240 0.030 0.592 -0.120 0.093 0.168 1.000 Sig. 0.338 0.148 0.448 0.002 0.303 0.344 0.234 N 21 21 21 21 21 21 21 21 102 

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