( ' anaanv .2007 Aiiichigan State University This is to certify that the thesis entitled BODYBLADE: EFFECTS OF RHYTHMIC STABILIZATIONS ON ROTATOR CUFF MUSCLES MEASURED BY EMG, AMONG FEMALES AGES 19-25 presented by Kristen Rodriguez Sutton has been accepted towards fulfillment of the requirements for the MS degree in Kinesiolgy / Major Professor’s Signature 6/é/06 Date MSU is an Aflinnative Action/Equal Opportunity Institution _ —.—.—.— -A-n-n---------I-D-I-l-n-n-o----n--l-l--n-l-t-I-o-J--I-I-1—h-I-I-‘-I-O-I-v-o-O-l-I-.-l-‘--t--'-'. v V'fi o «' PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 5/08 KtlPrqlAchresIClRC/DateDue indd BODYBLADE: EFFECTS OF RHYTHMIC STABILIZATIONS ON ROTATOR CUFF MUSCLES MEASURED BY EMG, AMONG FEMALES AGES 19-25. BY Kristen Rodriguez Sutton A THESIS Submitted to Michigan State University In partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Kinesiology 2006 ABSTRACT BODYBLADE: EFFECTS OF RHYTHMIC STABILIZATIONS ON ROTATOR CUFF MUSCLES MEASURED BY EMG, AMONG FEMALES AGES 19-25. BY Kristen Rodriguez Sutton Purpose: The purpose of this study was to examine the difference in the amount of muscle recruitment across six shoulder muscles comparing the four positions performing both static holds and rhythmic stabilizations using the Bodyblade”. Methods: A total of 20 female subjects volunteered for this study. Using electromyography, all participants performed eight exercises using the Bodyblade“ (four static hold exercises, four rhythmic stabilization exercises) in four different shoulder positions. Results: Results revealed a greater percent of maximal voluntary contraction while performing rhythmic stabilization compared to static hold activities using the Bodyblade". Teres minor produced the greatest percent of muscle recruitment during the Bodyblade" exercises in the shoulder shrug, front raise and IR/ER positions. The front raise Bodyblade“ exercise produced the greatest muscle recruitment across the six muscles. Conclusion: Results of this study suggest that rhythmic stabilization provides greater rotator cuff muscle recruitment compared to a static hold with the Bodyblade". This supports the use of the Bodyblade“ among sports medicine professionals as a proficient rehabilitation tool for the rotator cuff muscles. DEDICATION To Rod and Margaret Rodriguez You have brains in your head, You have feet in your shoes You can lead you life any direction you chose You’re on your own now And you know what you know And you are the GUY Who will decide where you go! DR. SUEUSS ifi ACKNOWLEDGEMENTS I would like to acknowledge the efforts of my thesis committee. Through all the trials and tribulations in the past two years, you stood by my side, giving me confidence, support and inspiration. Thank You for all your time and effort. To Dr. Powell, thank you for help as an advisor for the past two years. All your efforts are greatly appreciated. To Dr. Tracey Covassin, thank you for all your support. Thank you for the late evenings, early morning testing subjects and for all your tireless efforts to help make this happen. You have been a mentor, a teacher and most of all a friend. To Dr. Larry Nassar, thank you for the inspiration to become a better athletic trainer, as well as a better person. Thank you for your guidance and willingness to help. To Dr. Derek Scott, thank you for your time and knowledge. Your willingness to help was greatly appreciated. To GM Pugh and Nathan Cline, thank you for sharing your experiences, for holding me to high standard and believing that I was capable of achieving them. Thank you for your guidance as mentors and as friends. To the graduate athletic training class of 2006, thank you for being a second family. Julie, thank you for lending a shoulder to cry on or a ear to talk to. I could not have done it without you. To my parents, thank you for always being there, for all your love and support throughout the past 23 years. And to Kenny, Charlie and Casey, thank you for your light heartedness and love. To Justin, thank you for always being a friend when times got tough. iv TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES CHAPTER 1 Overview of Problem Significance of Problem Statement of the Purposem. Need for Study Research Question ..... . Definitions CHAPTER 2 Anatomy of the Shoulder Supraspinatus Infraspinatus Teres Minor Subscapularis Bodyblade” T Static verses Rhythmic Stabilization using the Bodyblade Use of Specific Shoulder Positions Muscle Recruitment during Activity Variation ........... Motor Unit Recruitment using Electromyographymmmm Electromyography Noise Interference Implication of Literature Review to the Proposed Study CHAPTER 3 Research Design Participants Instrumentation Bodyblade“I Electromyography Data Collection Procedures Statistical Analysis CHAPTER 4 Subject Demographics Static Stabilization verses Rhythmic Stabilization Shoulder Shrug Lateral Raise vii xi \lmmmeH 10 10 ll 11 ll 13 15 17 18 l9 19 20 22 22 24 25 25 25 27 31 33 34 34 34 35 Front Raise Internal Rotation/External Rotation Rotator Cuff and Accessory Shoulder Musculature ........ Anterior Deltoid Pectoralis Major Serratus Anterior Supraspinatus Infraspinatus Teres Minor CHAPTER 5 Analysis of Static verses Rhythmic Stabilization Exercises Analysis of the Six Muscles across the Eight Exercises Utilization and Clinical incorporation of the Bodyblade“ ' Limitations Future Research Implications Conclusion BIBLIOGRAPHY APPENDICIES A. UCRIHS Study Approval Form B. Human Subjects Consent Form C. Health History Questionnaire D. Descriptive Statistics vi 36 37 38 38 39 4O 41 42 43 44 45 47 48 49 50 51 53 56 58 61 64 66 LI ST OF TABLES Table 1: Subject Demographic Information 34 Table 2 Comparison of Means between Static Hold Exercise and Rhythmic Stabilization" Exercise by the Anterior Deltoid 64 Table 3 Comparison of Means between Static Hold Exercise and Rhythmic Stabilization” Exercise by the Pectoralis Major 64 Table 4: Comparison of Means between Static Hold Exercise and Rhythmic Stabilizationm Exercise by the Serratus Anterior 6S Table 5: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization” Exercise by the Supraspinatus 6S Table 6: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization“ Exercise by the Infraspinatus 66 Table 7: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization”I Exercise by the Teres Minor 66 Table 8: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization”I Exercise in Shoulder Shrug Position 67 Table 9: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization" Exercise Lateral Raise Position 67 vfi Table 10: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization” Exercise Front Raise Position 68 Table 11: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization” Exercise IR/ER Position 68 Table 12: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization" Exercise in Shoulder Shrug Position 69 Table 13: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization” Exercise in Lateral Raise Position 69 Table 14: Comparison of Means between Static Hold Exercise and Rhythmic Stabilizationm Exercise in Front Raise Position 69 Table 15: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization" Exercise in IR/ER Position 70 Table 16: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization" Exercise by the Anterior Deltoid 7O Table 17: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization” Exercise by the Pectoralis Major 70 Table 18: Comparison of Means between Static Hold Exercise and Rhythmic StabilizationTu Exercise by the Serratus Anterior 71 V/iii Table 19: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Supraspinatus 71 Table 20: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Infraspinatus 71 Table 21: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Teres Minor 71 Table 22: Pair wise Comparison for Shoulder Shrug with Static Hold 72 Table 23: Pair wise Comparison for Shoulder shrug with Rhythmic Stabilization 73 Table 24: Pair wise Comparison Static Hold for Lateral Raise with 74 Table 25: Pair wise Comparison Rhythmic Stabilization for Lateral Raise with 75 Table 26: Pair wise Comparison for Front Raise with Static Hold. 76 Table 27: Pair wise Comparison for Front Raise with Rhythmic Stabilization 77 Table 28: Pair wise Comparison for IR/ER with Static Hold 78 Table 29: Pair wise Comparison for IR/ER with Rhythmic Stabilization Exercise 79 ix Table 30: Repeated Measures ANOVA for Delayed Comparing Four different Positions during Static Hold and Rhythmic Stabilization across Six Muscles 80 Table 31: Repeated Measures ANOVA for Delayed Eight Exercises Comparing Six Muscles across Eight Exercises . 80 LIST OF FIGURES Figure 1: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Shoulder Shrug Position .. 35 Figure 2: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Lateral Raise Position .. 36 Figure 1: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Front Raise Position .. 37 Figure 4: Comparison of Means between Static Hold Exercises and Rhythmic Stabilization Exercises in Internal/External Position 38 Figure 52: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Anterior Deltoid 39 Figure 63: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Pectoralis Major 40 Figure 74: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Serratus Anterior 41 Figure 85: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Supraspinatus 42 xi Figure 96: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Infraspinatus 42 Figure 7: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Teres Minor 43 xfi CHAPTER 1 INTRODUCTION Overview of Problem As insight develops in the fields of exercise physiology and biomechanics, rehabilitation tools are greatly enhanced. Based on the theory of proprioception and neuromuscular facilitation, the Bodyblade” was developed as a self executed rhythmic stabilization tool. This investigation attempted to identify which rotator cuff muscles were recruited while using the BodybladeTu for static hold and rhythmic stabilization exercises. Differences between six muscles were observed in order to determine which had the greatest and which had the least amount of muscle recruitment across a total of eight exercises. In 1994, Bruce Hymanson developed the Bodybladem to strengthen and rehabilitate the shoulder (www.bodyblade.com). Most clinicians believe it is obvious that the rotator cuff muscles are activated while performing these exercises. Yet, little research has been published on recruitment of muscle activity when using the Bodyblade”. Stone, Partin, Lueken, Timm, & Edward (1994) examined the Bodyblade” for performance and strength enhancements while Schulte & Warner (2001) used a Cybex Electronic Digital Inclinometer 320 to measure gains in proprioceptive response. Although both of these studies showed an overall gain in proprioception and function, the question arises as to the amount of neuromuscular recruitment initiated by the rotator cuff muscles when performing rhythmic stabilizations using the Bodyblade”. By investigating the motor recruitment of the rotator cuff muscles and additional scapular stabilizers alternative exercise tools can be identified. Over the past decade, Bodybladem has been a rehabilitation tool that allows athletes to work scapular stabilizing muscles through self induced rhythmic stabilization. The Bodybladem was incorporated into rehabilitation protocols to produce co—contractions of shoulder musculature. This creates approximation of the shoulder while enough force is produced to rhythmically move the tips of the blade. Although there is little research to support specific muscle innervations during rhythmic stabilization exercises using the Bodyblade", there have been a number of studies discussing rhythmic stabilization as a component of proprioception (Leggin & Kelly, 2000). Theoretically, rhythmic stabilization exercises using the Bodyblade" promote synergistic muscles to co-contract, improving proprioception of the rotator cuff muscles. Previous research on Bodyblade“’I examined performance enhancement protocols in sports such as baseball and softball (Schulte & Warner, 2004). The athletes tested used the Bodyblade” to mimic their throw through a full range of motion. Throwing acceleration was measured before and after completing the Bodyblade” regiment. Results suggest that using Bodyblade“I increased speed in which the ball was thrown. Significance of Problem The Bodyblade” is used both in the medical world and among strength and conditioning specialists. The Bodyblade” is an integral part of many rehabilitation and maintenance protocols for athletes. By providing evidence of the effectiveness in activating the rotator cuff muscles using the Bodyblade", more athletic trainers may be inclined to use it as an alternative to manual rhythmic stabilization exercises. Furthermore, it may allow athletes to facilitate strengthening and maintenance rehabilitation protocols at home more regularly. Sports rehabilitation may not be the only atmosphere for the Bodyblade". Rhythmic stabilization exercises have shown improvements in an industrial setting for adhesive capsulitis in middle—aged adults (Rizk, Christopher, Pinals, Higgins, & Frix, 1983). In this case a Bodybladem may help factory and construction workers maintain shoulder strength and stability after physical therapy is completed. Hintermeister, Lange, Schultheis, Bey, and Hawkins (1998) determined a “take home” program of Thera—band exercises for postoperative patients improved strength and proprioception. A similar protocol could be created for the Bodyblade” which may produce parallel benefits for the patients. The shoulder is an inherently unstable joint due to the anatomical relationship of the glenoid fossa and the humeral head, creating a lack of bony stability. This relationship reinforces the importance of surrounding muscular strength, the rotator cuff muscles. The glenohumeral joint relies on both static and dynamic stabilizers in order to function properly. Neuromuscular control is dependent on proprioceptors located in the joint capsule, as well as muscular strength. Many injuries are sustained when stress is placed on a shoulder with weak surrounding musculature. Likewise, after a traumatic injury has occurred to the shoulder, the rotator cuff muscles play an active role in protecting it from further injury. After surgery, it is vital for patients to maintain strength of the rotator cuff muscles in order to maintain stability. A study by Kelly, Williams, Cordasco, Backus, Otis, Weiland, Craig, Wickiewicz, & Warren (2005) was conducted using symptomatic and asymptomatic adults with rotator cuff tears. Electromyography was used to measure rotator cuff activation during the performance of 10 functional tasks. Asymptomatic participants tended to have increased firing patterns of the muscles, while symptomatic participants continued to rely on “torn tendons and periscapular muscle substitution, resulting in compromise” (Kelly et al., 2005). Researchers suggested that the rotator cuff muscles aid in protecting the shoulder from major injury. Myer, Yan—ying—yu, McMahon, Rodosky, and Lephart (2004) demonstrated greater firing pattern in unstable an glenohumeral joint. Statement of the Purpose The purpose of this study was to determine the amount of muscle recruitment occurring across six shoulder muscles during static and dynamic actions of the Bodyblade", measured by electromyography (EMG). The goal was to specifically describe which shoulder position was most effective in facilitating recruitment of the six shoulder muscles examined; anterior deltoid, serratus anterior, pectoralis major, supraspinatus, infraspinatus and teres minor. From these results, specific shoulder positions can be implemented in exercise and rehabilitation that result in high levels of muscle activation. Need for Study The current study will help develop suggestions for arm positions that may improve rotator cuff muscle rehabilitation protocols. Despite the popularity of the Bodyblade”, there is a limited amount of credible research published. Data collected may assist in validating techniques currently used by medical professionals by clarifying which muscles are recruited during specific exercises. In contrast to most studies incorporating the Bodyblade", which use functionality and performance enhancement as a standard for improvement, this study will look at the EMG activity of shoulder muscles during Bodyblade" exercises. 'Research Questions 1. Is motor unit recruitment during rhythmic stabilization with the Bodyblade“I greater than recruitment during static contraction for active female college students across all four exercises? 2. Which of the six shoulder muscles has a greater percentage of reference contraction during each of the eight activities? 3. Which of the eight tests require the overall greatest amount of muscle recruitment of the six muscles being monitored? 4. Which of the eight tests require the overall least amount of muscle recruitment of any of the six muscles being monitored? Definitions The Bodyblade” is a fiber glass blade containing a plastic handle in the center and two flexible plastic tips housing weighted pieces. Using inertia, the Bodyblade” is oscillated using the shoulder muscles, as well as others, to create the desired motion. A variety of blade length and weights are available depending on desired results. The blades may also vary by pliability of the blade. The CXT was used in this study. Electromyography (EMG)- uses a recording device that measures the electrical impulse of the muscle in order to detect contraction or motor unit recruitment. EMG may be performed with electrode contact on the surface of the skin or with fine needles placed into the muscle belly. Polymeric— the process of muscular activity, which involves the eccentric loading of a muscle, followed by an immediate concentric unloading. Proprioception— the position sense of awareness as to where the body is in space. Proprioceptive neuromuscular facilitation- A variety of techniques used to perform rehabilitation using all three planes of motion in the body and the proprioceptive input from the involved joints and muscles. Rhythmic stabilization— an isometric contraction of the agonist and antagonist muscles, producing co- contractions of synergistic muscles and aiding in stability. Rotator cuff muscles- a musculotendonous structure about the capsule of the glenohumeral joint, including the 1) supraspinatus, 2) infraspinatus, 3) teres minor, and 4) subscapularis. A portion of the capsule is formed by the blending of the inserting fibers of these muscles which provide mobility and strength to the shoulder joint). CHAPTER 2 REVIEW OF LITERATURE Anatomy of the Shoulder Due to the lack of bony stability, the shoulder relies on the surrounding musculature to maintain the strength and proprioception necessary to move. The lack of bony stability creates a larger amount of force placed on the shoulder musculature; therefore, the rotator cuff muscles must withstand the increased load. The rotator cuff muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) play an active role in maintaining the stability of the glenohumeral joint. The rotator cuff sustains a number of different injuries including strains, tears, and avulsions. The glenohumeral joint is comprised of four muscles, three of them inserting on the greater tubercle of the humerus. The acronym used to remember their order of origin superior to inferior is SIT: supraspinatus, infraspinatus, and teres minor. The forth rotator cuff muscle is the subscapularis which inserts on the lesser tubercle of the humerus. The subscapularis is not directly palpable and holds little reliability when pinpointing for using fine wire needles and will not be utilized in this study. The infraspinatus, supraspinatus, and teres minor will be tested via fine wire EMG. Supraspinatus The supraspinatus originates on the middle two thirds of the supraspinous fossa and inserts on the superior aspect of the greater tubercle. To test this muscle for a reference contraction, the subject should stand with both shoulders abducted to 90 degrees, horizontally adducted 30 degrees, and internally rotated so the subject's thumbs face the floor. The tester resists maximal shoulder abduction at the forearm (Konin, Wiksten, Isear, & Brader, 2002). Infraspinatus The infraspinatus originates along the medial two thirds of the infraspinous fossa of the scapula and inserts in the middle facet of the greater tubercle of the humerus and the shoulder joint capsule (Kendall, McCreary, & Provance, 1993). In order to perform a manual muscle test, the subject must be in a seated position with the shoulder at the side and the elbow flexed to 90 degrees. The subject then resists external rotation while manual pressure is applied at the forearm. This muscle is critical in the stabilization of the humeral head in the glenoid 10 fossa. The muscle’s predominate action is external rotation. Teres Minor The teres minor originates on the upper two—third of the dorsal surface of the scapula’s lateral boarder (Kendall, McCreary, & Provance, 1993). It inserts slightly more inferior on the greater tubercle than the infraspinatus muscle. By remembering SIT, the insertions move superior to inferior. Subscapularis The subscapularis is a challenge to palpate, making it difficult to insert an EMG wire. The subscapularis originates on the upper two—thirds of the dorsal surface of the scapula and inserts on the lesser tubercle of the humerus. It is the primary internal rotator of the shoulder. Kendall, McCreary, and Provance (1993) describe the main action as medial rotation providing stabilization of the humeral head in the glenoid fossa. Bodyblade” The Bodyblade” is a fiberglass blade consisting of a handle in the center and two flexible, weighted plastic tips on each end. The Bodyblade” uses rhythmic stabilization by oscillating the tips of the blade throughout a range of different shoulder positions. 11 Rhythmic stabilization incorporates the use of both agonist and antagonist muscles co—contracting while extraneous perturbations, or forces, are exercised on the body part. This technique combines proprioception and neuromuscular stimulation to strengthen and re—educate the glenohumeral joint. Rizk et al. (1983) showed rhythmic stabilization, to be an effective method of rehabilitation for adhesive capsulitis (frozen shoulder). By the improvements seen in shoulder motion, this study suggests that rhythmic stabilization is effective for proprioception and range of motion improvements, not necessarily strength gains. Although frozen shoulder is an extreme shoulder pathology and rhythmic stabilization is only one facet of proprioceptive training, it illustrates that there is increased rotator cuff activity during proprioceptive exercises. Stone, Partin, Lueken, Timm, and Edward (1994) discussed the importance of sports specific proprioceptive training. Rehabilitation suggestions were made comparing open kinetic chain athletes consisting of volleyball players, basketball players, and weight lifters, to closed chain athletes consisting of gymnasts, swimmers, canoeists, rowers, and kayakers. According to Stone et al. (1994), it was most beneficial for an athlete to begin rhythmic 12 stabilization through a range of motion as soon as pain and strength permitted as well as progress into upper body weight bearing proprioceptive exercises. This investigation reinforces the importance of rhythmic stabilization as a rehabilitation technique for the upper extremity. Static verses Rhythmic Stabilization using the Bodyblade" Proprioception is defined as the awareness and understanding of the shoulders position in space and how it adjusts to external forces placed upon it. A key component in rehabilitation of the shoulder is proprioception. The rhythmic stabilization technique targets an increase in proprioception. .Due to the lack of structural stability, it is important for the shoulder to regain a sense of position and kinesthesia. Exercises provided by oscillatory devices, such as the Bodyblade”, are termed “co—activation exercises.” This concept entails reciprocal recruitment of the agonist and antagonist muscles in a synergistic fashion. The synergistic contraction helps maintain joint stability by co-contracting against potentially harmful external forces. This leads to the idea that there is more muscle activation with rhythmic stabilization when compared to static hold exercises. 13 Strength may be measured by a reference contraction or through sport specific functional testing. Armstrong (2002) examined the functionality of 17 male college baseball players. No direct improvement was shown in strength, yet through functional testing, throwing velocity improved following Bodyblade“ training Myers et al. (2004) described the need for proprioceptive rehabilitation, incorporating neuromuscular stimulation in patients with anterior shoulder instabilities. A comparison was made between patients with and without anterior shoulder instabilities during upper extremity perturbations in an externally rotated position. The research demonstrated both weakness and latent reactions of the musculature surrounding the shoulder. Signorile, Lister, Rossi, Ma, Stoutenburg, Adams, and Tobkin (2005) used EMG to measure the amount of motor unit firing of the scapular stabilizers during Bodyblade“, Thera-band, and cuff weight exercises. EMG recordings were collected for the upper trapezius, lower trapezius, and serratus anterior. Only two shoulder positions were examined, shoulder flexion and shoulder abduction. It was concluded that the upper trapezius had significantly greater motor unit recruitment while performing the Bodyblade” exercises when compared to the Thera-band and 14 the cuff weight. The greatest percentage of reference contraction for the lower trapezius was recorded during Bodyblade” while the shoulder was in an abducted position. During flexion and abduction, both the Bodyblade” and Thera-band exercises produced an overall greater percentage of contraction when compared to cuff weight exercises. Signorile et al. (2005) was one of the first studies published to use EMG in measuring muscular activity of the shoulder muscles with the use of the Bodyblade”. Although, Bodyblade” exercises are based on proprioception, not strength, this leads to the idea that the use of the Bodyblade“ will cause greater recruitment among rotator cuff muscles during rhythmic stabilization than with a static hold. Specific Shoulder Positions The four positions used in the current study are commonly included in the rehabilitation protocol suggested by Bodyblade“. The four different positions examined during both the Bodybladem and static hold exercises were: Shoulder Shrug (SS): neutral shoulder adduction, elbow fully extended Lateral Raise (LR): shoulder in 90 degrees of abduction, elbow fully extended, forearm pronated 15 Front Raise (FR): shoulder in 90 degrees of forward flexion, forearm pronated Internal/External Rotation (IRER): neutral shoulder adduction, 90 degrees of elbow flexion, forearm in neutral These four positions are also common in shoulder rehabilitation protocols using Thera-bands and cuff weights. Using similar positions, Hintermeister et al. (1998) studied seven exercises: external rotation, internal rotation, forward punch, shoulder shrug, and seated row with a narrow, middle, and wide grip. Increased motor recruitment of the supraspinatus, subscapularis, anterior deltoid, infraspinatus, pectoralis major, latissimus dorsi, serratus anterior, and trapezius was demonstrated during elastic band exercises. Townsend, Jobe, Pink, & Perry (1991) incorporated similar positions in their study which utilized baseball athletes participating in a shoulder strengthening maintenance program. The positions that were examined included arm elevated in the coronal plane, arm elevated in the sagittal plane, press-ups, and shoulder internal and external rotation. Each of the exercises demonstrated increased recruitment of the rotator cuff muscles. Force couples were examined of the supraspinatus and anterior 16 deltoid; these muscles aid in stabilizing the humeral head in the glenoid fossa. The results indicated that the exercises performed in the scapular plane above 90 degrees produced the highest percentage of reference contraction. Wise et al. (2004) discussed the percentage of reference contraction recruited during AROM of the shoulder in forward flexion. Results found the greatest percentage of muscle contraction in the supraspinatus followed by anterior deltoid, infraspinatus, and pectoralis major, respectively. .Muscle Recruitment during.Activity variations An examination by Hinestermeister et al. (1998) focused on muscle recruitment during Thera-band activities. For example, it was recognized that the subscapularis was used predominantly during internal rotation when compared to the infraspinatus. The infraspinatus produced the greatest percentage of muscle contraction during external rotation. The Thera-band activity in the shoulder shrug position, similar to neutral shoulder adduction, incorporated the greatest number of muscles used simultaneously, five of the seven. A number of rehabilitation exercises using elastic resistance were discussed, each of which using fine wire EMG. The findings proved for each exercise focus on a different set of 17 muscles. Therefore, it is demonstrated that muscles produce an increased contraction depending on the position of the arm and the external forces created through movement of the Bodyblade” during rhythmic stabilization. MOtor Unit Recruitment using Electromyography EMG has been used to measure the relative activation of motor units in different shoulder muscles by examining the electrical potential in the muscle. An increase in the rate of motor unit activation signifies an increase in force development. When discussing various proprioceptive techniques it is important to include the effects of motor unit reflexes. An increase in the reflex motor unit contraction may indicate an increase in the rate of force development. Also, an increase in neutral adaptations may result in an improvement in co-contractions between agonist and antagonists muscles during large motor movements. Muscular strength can be improved by increasing the number of motor units activated or by increasing the firing rate of the active motor units (Friedhelm & Culcea, 2004). Systematically, the muscle will increase the number of motor units recruited, in size order, smallest units first followed by the larger units. The additional number of 18 recruited motor units aids in a more rapid initiation of muscle contraction. Electromyography Many researchers have studied the Bodybladem measuring improvements in performance using methods such as acceleration, velocity, and strength (Schulte et al., 2001). To date, no studies have examined the activation of rotator cuff muscles during rhythmic stabilization using the Bodyblade”. Signorile et al. (2005) recently observed EMG analysis of the scapular stabilizers which compared Bodyblade”, Thera-band, and cuff weight activities. Each muscle was tested and recorded as a percentage of reference contraction. The reference contraction assisted in normalizing the data so the muscles were able to be cross examined. Nbise Interference The major problem with using fine needle EMG during Bodyblade” activities was input impedance (Rogoff et al., 1961). The use of “quiet files” assisted in establishing a baseline measurement. This helped make a greater distinction between time of activity and baseline recordings. A “quiet file” is an EMG recording done while the subject is sitting at an inactive state. The “quiet file” provided a reason for performing a static hold as a 19 control condition and for establishing a baseline. This aided in determining an increase in percentage of muscle contraction during Bodyblade” activities. Rhythmic Stabilization using the Bodyblade“ Although few studies have measured Bodybladem exercises as a direct cause of rotator cuff muscle activation, it was measured indirectly through a number of studies. Most studies used Bodyblade" exercises to examine the functional improvements of an activity following a rehabilitative protocol rather than the neuromuscular aspect of use. Rhythmic stabilization using the Bodyblade“ showed improvement in areas such as throwing acceleration (Schulte, 2001.) Bodyblade“I exercises are one of many forms of rhythmic stabilization techniques. Leggins and Kelley, (2000) discussed this technique as a form of rehabilitation tool. The rehabilitation programs in post surgical rotator cuff patients were investigated. The rehabilitation program included Bodyblade” exercises as a proprioceptive activity. Similarly, rhythmic stabilization demonstrated proficient gross improvements in shoulder rehabilitation in patients with adhesive capsulitis (Rizk et al., 1983). By using EMG to detect the difference in muscle firing patterns between static hold and rhythmic 20 stabilization, new strengthening protocols may be developed. 21 CHAPTER 3 METHODS The purpose of this study was to determine the amount of muscle recruitment occurring across six shoulder muscles during static and dynamic actions of the Bodyblade”, measured by electromyography (EMG). The goal was to specifically describe which shoulder position was most effective in facilitating recruitment of the six shoulder muscles examined; anterior deltoid (AD), serratus anterior (SA), pectoralis major (PM), supraspinatus (SS), infraspinatus (IS), and teres minor (TM). Research design A randomized, counterbalanced, within-subject experimental design was used to compare the effects of static hold and rhythmic stabilization on four different shoulder positions. Shoulder Shrug (SS): neutral shoulder adduction, elbow fully extended Lateral Raise (LR): shoulder in 90 degrees of abduction, elbow fully extended, forearm pronated Front Raise (FR): shoulder in 90 degrees of forward flexion, forearm pronated 22 Internal/External Rotation (IRER): neutral shoulder adduction, 90 degrees of elbow flexion, forearm in neutral The within-subjects design helped control for subjects' variability, such as individual differences in flexibility and strength. The counterbalancing technique helped control for practice affects that result from repeated Bodyblade” testing. The dependent variable for this study was the EMG data regarding muscle recruitment for six shoulder muscles. The data points included intramuscular fine wire needles placed in the muscle belly of three muscles; infraspinatus, supraspinatus, and teres minor. Surface electrodes were placed on the serratus anterior, anterior deltoid and pectoralis major. The independent variables for this study were the static hold exercises verses rhythmic stabilization exercise using the Bodyblade”, the four different shoulder positions tested, and the six shoulder muscles examined. Little research has validated the use of Bodyblade" as a proficient tool for rotator cuff rehabilitation and strengthening. It is unknown as to which muscles are actually firing during specific Bodyblade" exercises and which of these exercises most effectively facilitate 23 activation of the rotator cuff muscles and scapular stabilizers. This protocol studied the effects of static hold verses rhythmic stabilization using electromyographical analysis of muscle recruitment. Participants Twenty healthy females between the ages of 18 and 26 were used for this study. Participants were accepted if they were recreationally active, defined as participating in some form of physical activity a minimum of two days a week and not playing a high level sport (collegiate or professional level). Participants were recruited on a volunteer basis from a Midwestern Division I university. Consent forms and a health history questionnaire were completed and signed by all participants prior to data collection. Females with a previous history of shoulder surgery or cervical spine pathologies were excluded from the study. Individuals with major wrist, elbow, hand, or shoulder problems (i.e. chronic pain, previous diagnosis of shoulder pathology, impingement, sprains, moderate strains) during the past six months were also excluded. All participants self reported right arm dominance. Participants were restricted from upper body maximal lifting activities for at least four days prior to testing. A waiver of informed consent was required to be signed 24 prior to the beginning of the study in order to participate. Instrumentation Bodyblade” A CXT Bodybladem was used during this study. It was 40 inches long and had an approximate weight of 1.25 lbs. It is recommended for “increasing muscular endurance, balance, and coordination” (www.bodyblade.com). This Bodyblade“ is commonly used to strengthen shoulders during rehabilitation and functional exercises. Electromyography An eight-channel FM transmitter attached to the Myopac system (Run Technologies, Mission Viejo, CA) was used to detect the EMG activity of the serratus anterior, anterior deltoid, pectoralis major, infraspinatus, supraspinatus, and teres minor. The Myopac system is equipped with eight channels, each with two leads. Each of the leads has an alligator clip that attaches to the surface electrodes (AMBU, Blue Sensor electrodes, Glen Burnie, Maryland). In order to use the fine wires, each channel required individual adapter. The adapters consisted of a small rectangle with two male connectors for the alligator clips to attach and two coils to attach the fine wires. The adapters were placed on the skin using Mastisol and tape. 25 Once all electrode placements were verified through manual muscle tests, the subjects began their randomized trials. EMG data were measured by a raw voltage (volt * second) using Datapac 2K2 (Run Technologies, Mission Viejo, CA). EMG raw scores (volt* seconds) were then divided by an average reference contraction to produce a percentage of the reference contraction, similar to the procedure for measuring maximal voluntary contraction (MVC) described by Hintermeister et al. (1998). Reference contractions were obtained through a control isometric contraction. Each subject performed a reference contraction for each muscle pre-exercise and post-exercise. Each contraction lasted five seconds with at least three to five seconds of rest between the contractions. For each muscle, reference contractions were performed with a joint configuration that maximized EMG activity under isometric conditions and within a normal range of motion. The positions selected for reference contraction performance isolated each respective muscle, based on muscle strength testing positions (Kendall, McCreary, & Provance, 1993). The reference contraction value represents the average taken from pre-exercise and post-exercise manual muscle tests for each muscle. The reference contraction was used as a 26 baseline for EMG data collection during the specified activities. During an EMG reading, the signals from the leads inserted or attached to the muscle were passed to a battery operated Myopac eight-channel FM transmitter (RUN Technologies, Mission Viejo, CA). The signal was amplified by a gain of 1000 V with a single—ended amplifier with impedance greater than ten MOmega. Waveform processing was filtered with a notch Butterworth filter (60.0 Hz) and common mode rejection ratio of 130 dB at direct current with a minimum of 85 dB across the entire frequency of 10- 500 Hz. A Datapac receiving unit with a sixth order filter (gain 2, total gain 2000) further amplified the signal. The analog signal was converted to a digital signal by an analog-to-digital converter card (Run Technologies, Mission Viejo, CA) and was stored in the Datapac Software, version 3.00. The raw digital signal (reference contraction and trials) was sampled at a rate of 960 Hz and smoothed using a root mean square algorithm over a SO—ms moving window. Data Collection Procedures Testing involved two sessions, the first lasted only 15 to 20 minutes and the second involved a 60-minute time period. The first session tested the proficiency of rhythmic stabilization with the Bodyblade”. Participants 27 were considered proficient when they are able to flex the tips of the Bodyblade” with minimal movement of the shoulder. During the second testing session, participants were placed in a “quiet room” in order to reduce extraneous noise and verify proficiency of the Bodyblade” exercises. They were then familiarized with the manual muscle tests used to calculate reference contractions for each individual muscle. Participants remained seated on a medical table while the right side of the body was prepared for electrode placement. Over the areas of surface electrode placement, the participants were shaved, abraded, and cleansed with 70% isopropyl alcohol pads. The participants were then cleansed with alcohol pads over the posterior aspect of the right shoulder where the fine wires were to be inserted. All muscles with superficial orientation were assessed with surface electrodes (pectoralis major, anterior deltoid, and serratus anterior). Surface electrode placement was determined by finding the mid—point between the origin and insertion of the designated muscle. Serratus anterior was generally placed at the level of the seventh and eighth rib. After prOper preparation, two forty—millimeter-diameter self- adhesive silver/silver-chloride bipolar surface electrodes (AMBU, Glen Burnie, Maryland) were placed parallel to the 28 underlying muscle fibers. Each pair of surface electrodes had a two cm separation from the center of each electrode (Basmajian et al, 1989). Correct position of the electrode was confirmed by real-time visual inspection of the EMG signal on an oscilloscope during manual muscle testing that isolated activation in the designated muscle (Basmajian et al., 1989). Then, under sterile conditions, the fine wire needles were inserted by a sports medicine physician into the infraspinatus, supraspinatus, and teres minor. All participants were given the option to use Flori—Methane spray and stretch (Gebauer Company, Clevland, OH) for an analgesic effect prior to insertion of the fine wire needles. The fine wire electrodes consisted of a 0.002 x 8” nickel alloy wire insulated with nylon (Chalgren Enterprise, Inc. Gilroy, CA). This type of fine wire was chosen according to published recommendations (Kelly et al., 1997). Fine wires were inserted intramuscularly into the respective muscle via a disposable paired fine wire EMG needle electrode 1.5-in (3.81-cm), 27-gauge needle (Chalgren Enterprise, Inc. Gilroy, CA) (Geiringer et. a1, 1998). Two single-wire electrodes were inserted into each muscle at an interelectrode distance of one cm (Kelly et al., 1997). A forty millimeter-diameter self—adhesive silver/silver—chloride bipolar surface electrode (AMBU, 29 Blue Sensor electrodes, Glen Burnie, Maryland) was placed just inferior to the participant’s olecranon process to serve as the dispersion electrode. Prior to Bodybladem exercise, each participant was assigned a random order in which to perform the exercises. During the one—minute rest, the investigator told the participant the exercise they were to execute during the next 30-second exercise session. All participants used the right arm for all exercises. Four different positions were examined twice, once holding the Bodyblade“ in a static state and once using it during rhythmic stabilization exercises. The positions performed as a static hold acted as the control for the exercises executed with rhythmic stabilization. All eight exercises were completed in a randomly assigned order. The positions examined included: shoulder shrug, lateral raise, front raise, and internal/external rotation. No two subjects were given the same order of exercises. Each exercise was executed for 30 seconds with one minute rest between each test. During the 30 second exercise only three five-second intervals were analyzed; 5- 10 seconds, 15—20 seconds, and 25-30 seconds. After completion of all exercises, the participant performed the same manual muscle tests in the same order to calculate an 30 average reference contraction. Investigators then removed the electrodes and cleansed the affected area. The fine wires and electrode pads were removed from the participant and data were saved. Each participant was provided with a copy of the results of the study in order to better inform them of the purpose and significance of the study. If participants indicated an interest in the results of the study, they were provided with a copy of the abstract. Statistical Analysis Means and standard deviations were calculated for descriptive purposes. For clarification, the results section is limited to values based on percentage of reference contraction. Raw data that was measured in volt * seconds is available in the appendices. Reference contractions were measured as described in Muscles Testing Function (Kendall, McCreary, & Provance, 1993) for the anterior deltoid (AD), pectoralis major (PM), serratus anterior (SA), supraspinatus (SS), infraspinatus (IS), and teres minor (TM). Reference contractions were recorded prior to and again following testing exercises. The scores were combined and averaged to attain the number used as the divisor to determine percentage of reference contraction. Subjects with an increased percentage of reference contraction, when comparing static and rhythmic 31 stabilization exercises, indicated a greater amount of activity for that specific muscle in a single position. This helped normalize data across muscles to examine relative improvements from the control to experimental activities. A 2 treatment (experimental, control) X 8 exercises repeated measures analysis of variance (ANOVA) was conducted to analyze the effectiveness of each exercise. All eight EMG test scores were analyzed individually using a repeated measure ANOVA. Another 2 treatment (experimental, control) X 6 muscle (AD, PM, SA, SS, IS, TM) repeated measures ANOVA was conducted to determine the amount of muscle involved across the group. The level of significance was set at p = .05 and all analyses were conducted using SPSS version 11.1 for Windows (SPSS Inc., Chicago, IL). 32 CHAPTER 4 RESULTS The purpose of this study was to determine the amount of muscle recruitment occurring across six shoulder muscles during static and dynamic actions of the Bodyblade", measured by electromyography (EMG). For clarification, the results section is limited to values based on percentage of reference contraction. Raw data is measured in volt * seconds is available in the appendix. Static hold stabilization (SH) was used in order to compare the amount of muscle activity used while performing rhythmic stabilization (RS) exercise with the Bodyblade". The four positions performed in this study were: Shoulder Shrug (SS): neutral shoulder adduction, elbow fully extended Lateral Raise (LR): shoulder in 90 degrees of abduction, elbow fully extended, forearm pronated Front Raise (FR): shoulder in 90 degrees of forward flexion, forearm pronated Internal/External Rotation (IRER): neutral shoulder adduction, 90 degrees of elbow flexion, forearm in neutral. 33 Subject Demographics A total of 20 females (age = 21.15 i 1.76 years, height = 64.85 i 2.64 inches, weight = 143.35 i 21.35 lbs, arm length = 67.45 i 3.07 cm) volunteered to participate in the study (Table 1). Due to the within—subject experimental design, all subjects were considered part of both the experimental and the control groups. Table 1: Subject Demographic Information Demographics N Mean SD Age (years) 20 21.15 1.76 Weight (lbs) 20 143.35 21.35 Height (in) 20 64.85 2.64 Arm length (cm) 20 67.45 3.07 Static Stabilization verses Rhythmic Stabilization An individual repeated measure ANOVA was performed on each of the eight exercises across the six muscles. All eight exercises revealed significant differences across all six muscles (See Appendices, Table 22- 31). Shoulder Shrug Results reveals significant differences during rhythmic stabilization activities for shoulder shrug position between the six muscles (Ffiiuw = 532, P = 000). During the shoulder shrug position, the teres minor (TM) 34 displayed the greatest percentage of muscle contraction (74.23%) in comparison to the other five muscles tested (See Figure 1). Figure 1: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Shoulder Shrug Position Shoulder Shrug %of MVC Y9Q®9v99©4® Lateral Raise During both the static hold and rhythmic stabilization activities in the lateral raise position, there was a greater percentage of muscle recruitment from the supraspinatus (SH = 41.45%, R8 = 66.13%) and serratus anterior (SH = 37.97%, RS = 64.17%) compared to the anterior deltoid (SH = 32.66%, RS = 46.41%), teres minor (SH = 11.41%, RS = 51.32%), infraspinatus (SH = 17.83%, RS = 44.02%), and pectoralis major (SH = 12.51%, RS = 30.18%) muscles (See Figure 2). The lowest percentage of muscle 35 contraction during the lateral raise was static hold using the Bodyblade” for the pectoralis major. Figure 2: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Lateral Raise Position l Lateral Raise °/o of MVC Front Raise During the front raise activity, the greatest percentage of muscle recruitment was seen during the rhythmic stabilization activity in the teres minor (101.21%) and serratus anterior (78.09%) (See Figure 3, See Appendix Table, 9). Values greater than 100% exist due to the methods used to establish the percentage of reference contraction. As stated in chapter three, raw scores were divided by an average of two maximal contractions to produce the percentage of reference contraction. Teres minor revealed the lowest percentage of muscle recruitment during the static hold activity (22.41%). Pair-wise 36 comparisons revealed that the teres minor displayed the greatest change in the percentage of muscle contraction when comparing between the static hold and rhythmic stabilization activities. Figure 1: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Front Raise Position Front Raise 120 — 8 \\ ’ / ISH IRS %miNNC IS TM SA SS 2 AD Internal/External Rotation The teres minor (78.65%) produced the greatest percentage of muscle recruitment when compared to anterior deltoid (AD), pectoralis major (PM), serratus anterior (SA), supraspinatus (SS), and infraspinatus (IS) during the internal/external rotation rhythmic stabilization exercises. The AD (4.54%) displayed the lowest percentage of muscle contraction during the static hold position (See Figure 4, See Appendices Table 24). 37 Figure 4: Comparison of Means between Static Hold Exercises and Rhythmic Stabilization Exercises in Internal/External Position Internal/External Rotation ‘00 ISH IRS %>ofhmVC Rotator Cuff and Accessory Shoulder Musculature An individual repeated measure ANOVA was performed on each of the six muscles across the eight exercises. Each of the six muscles revealed significant differences across all eight exercises (See Appendices Tables 31-38). Anterior Deltoid The anterior deltoid displayed the greatest percentage of reference contraction when individuals performed the lateral raise (46.41%) and front raise (43.69%) using Rhythmic Stabilization activities with the Bodyblade” (See Figure 5). Static hold shoulder shrug position (1.09%) exhibited the lowest percentage of reference contraction. 38 Figure 52: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Anterior Deltoid Anterior Deltoid 5000 4000 3000 2000 1000 000 IISH IDES %of MVC Shoulder Lateral raise Front raise IFVER shrug SS-Shoulder Shrug, LR-Lateral Raise, FR-Front Raise, IR/ER—Internal External Rotation Pectoralis Major The greatest percentage of reference contraction for the pectoralis major occurred when performing IR/ER (54.54%) and FR (70.89%) during the rhythmic stabilization activity (See Figure 6). The lowest percentage of reference contraction occurred during the SS static hold position (6.08%). 39 Figure 63: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Pectoralis Major Pectoralis Major sum L) >.eomu E .00... 0 ans gzzom-r om- Shoulder shrug Lateral raise Front raise lR/EH SS—Shoulder Shrug, LR—Lateral Raise, FIE—Front Raise, IR/ER-Internal External Rotation Serratus Anterior The greatest percentage of reference contraction for the SA was demonstrated during the front raise rhythmic stabilization activity (78.09%) (See Figure 7). The second most efficient exercise in recruiting the serratus anterior muscle was shown in the lateral raise during the rhythmic stabilization activity (64.17%). The lowest percentage of reference contraction was recorded during the static hold shoulder shrug activity (9.09%). 40 Figure 74: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Serratus Anterior Serratus Anterior ISH DRS 9613fnnV13 Shoulder shrug Lateral raise Front raise lFt/ER Ss—Shoulder Shrug, LR—Lateral Raise, FR—Front Raise. IR/ER—Internal External Rotation Supraspinatus The supraspinatus displayed the greatest percentage of reference contraction when individuals performed the lateral raise during the rhythmic stabilization activity (66.13%) (See Figure 8). Static hold in both the IR/ER (5.46%) and shoulder shrug (6.97%) positions exhibited the lowest percentage of reference contraction. 41 Figure 85: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Supraspinatus Supraspinatus 80.00 60.00 40.00 . 20.00 % of MVC Shoulder shrug Lateral raise Front raise IFl/ ER ssAShoulder Shrug, LR—Lateral Raise, FR-Front Raise, IR/ER—Internal External Rotation Infraspinatus The front raise (63.71%) and IR/ER (52.83%) rhythmic stabilization activities produced the greatest percentage of muscle recruitment while the shoulder shrug static hold position (1.47%) produced the lowest percentage of muscle recruitment for the infraspinatus (See Figure 9). Figure 96: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Infraspinatus Infraspinatus 80.00 60.00 40.00 ISH HRS 20.00 7 % of MVC Shoulder shrug Lateral raise Front raise IR/ 53 SS—Shoulder Shrug, LR-Lateral Raise, FR-Front Raise, IR/ER—Internal External Rotation 42 Teres Minor The two activities that incorporated the greatest percentage of reference contraction for the teres minor were IR/ER (78.65%) and FR (101.21%) during rhythmic stabilization activities (See Figure 10). The lowest percentage of reference contraction was observed in the shoulder shrug static hold position (6.28%). Figure 7: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Teres Minor Teres Minor U >' E ISH .8 IRS o\° Shoulder shrug Lateral raise Front raise lR/BR SS—Shoulder Shrug, LR-Lateral Raise, FR-Front Raise, IR/ER-Internal External Rotation 43 CHAPTER 5 DISCUSSION The purpose of this study was to determine the amount of muscle recruitment occurring across six shoulder muscles during static and dynamic actions of the Bodyblade”, measured by electromyography (EMG). Results demonstrated four significant findings from this study. The four positions revealed a greater percentage of reference contraction while performing rhythmic stabilization compared to static hold activities using the Bodyblade”. Teres minor produced the greatest percentage of muscle recruitment when compared to anterior deltoid, pectoralis major, serratus anterior, supraspinatus, and infraspinatus during the rhythmic stabilization activity in the shoulder shrug, front raise, and IR/ER positions. The front raise rhythmic stabilization exercise produced the greatest overall muscle recruitment across the six muscles. The shoulder shrug static hold exercise produced the lowest overall recruitment of muscle activity. Analysis of Static verses Rhythmic Stabilization Exercises In all four positions, rhythmic stabilization with the Bodyblade“ produced a greater percentage of reference contraction when compared to static hold. Leggin and Kelly (2000) suggested rhythmic stabilization exercises should be incorporated during rehabilitation following rotator cuff surgery. They concluded that rhythmic stabilization enhances “strength, dynamic control, proprioception, and endurance training.” Similarly, the results of their study suggest integrating rhythmic stabilization exercises during shoulder rehabilitation to strengthen the rotator cuff muscles. In contrast to the current study, Schulte et al. (2001) used the Bodyblade” to examine proprioceptive response to exercise. Results demonstrated improvement in proprioception when incorporating the rhythmic stabilization compared to a control condition. Although there is no direct correlation between the two studies, there was an overall improvement with rhythmic stabilization compared to static hold using the Bodyblade”. The findings of the present study determined using the Bodyblade“ for rhythmic stabilization in the front raise position produced the greatest percentage of reference contraction. The pectoralis major, serratus anterior, and teres minor produced the greatest amount of activity during 45 this exercise. Hintermeister et al. (1998) observed the greatest percentage of MVC of the supraspinatus, anterior deltoid, and serratus anterior when examining the effects of elastic-band resistance on a forward punch activity. The serratus anterior, upper trapezius and lower trapezius produced the greatest percentage of MVC during rhythmic stabilization exercises in shoulder flexion when compared to the exercises performed with the Thera-band and cuff weights (Signorile et al., 2000). The study suggested that front raise BodybladeTM exercises should be incorporated in the clinical settings to increase strength of both the rotator cuff muscles and surrounding scapular stabilizers. By placing the shoulder in forward flexion, it cannot depend predominantly on ligamentous and bony support and must rely on the rotator cuff muscles and scapular stabilizing muscles to resist the oscillations of the Bodyblade“. The serratus anterior is predominantly used for protraction and helping to stabilize the scapula, whereas, the teres minor is utilized to maintain posterior capsular stability. A comparison between the four static activities revealed the shoulder shrug position elicited the lowest amount of muscle contraction. Similar to the study by Hintermeister et al. (1998) on elastic resistance, the 46 Bodybladem shoulder shrug activity exhibited the lowest percentage of reference contraction. A possible explanation may be due to positioning the shoulder in a gravity dependent position. In the same way, assuming capsular stability and intact surrounding ligaments, the humeral head is comfortably held in the glenoid fossa with minimal stress placed on adjoining musculature. In addition, Stone et al. (1994) described the benefits of incorporating proprioceptive exercises, similar to the rhythmic stabilization using the Bodyblade“. Analysis of the Six MUscles across the Eight Exercises Teres minor demonstrated the greatest percentage of reference contraction with rhythmic stabilization activities, while the anterior deltoid elicited the lowest percentage of reference contraction while using the Bodyblade“l for rhythmic stabilization. The serratus anterior displayed the greatest percentage of reference contraction and the teres minor revealed the lowest percentage of reference contraction during static hold activities. The increased use of the teres minor while performing rhythmic stabilization exercises may be attributed to the need for glenohumeral stability. The teres minor acts predominately as an external rotator and a posterior glenohumeral stabilizer, which is necessary to 47 perform oscillations of the Bodyblade“. Likewise, this may account for the increased use of the supraspinatus as a humeral head depressor. The supraspinatus aids in maintaining humeral head stability in the glenoid fossa. The use of the serratus anterior as a shoulder depressor and a scapular protractor may explain the increased activity while holding a Bodyblade" in a static position. The current study exhibited a greater percentage of muscle contraction for the serratus anterior, pectoralis major and anterior deltoid. This may be due to the extended length of time the subject held the Bodyblade”, resulting in recruitment of the scapular stabilizers in place of the rotator cuff muscles. Utilization and Clinical Incorporation of the Bodyblade" The present study provided a foundation for positions used during shoulder rhythmic stabilization using the Bodybladem in rehabilitation protocols. Until now, the Bodyblade” has been predominantly used as a tool for proprioceptive training. Demonstrating an increase in percentage of reference contraction suggests implementing the Bodyblade" for strengthening programs in the clinical setting. When treating impingement pathologies, clinicians may strengthen the teres minor to aid in depression of the humeral head and increase the subacromial space. In 48 addition, using the BodybladeTM for rhythmic stabilization in a front raise or IR/ER position may be most beneficial when working with patients lacking control of external rotation. In contrast, if the supraspinatus requires more strengthening, the lateral raise position may be more appropriate. To obtain the greatest percentage of muscle recruitment when rehabilitating the shoulder complex, it is recommended that sports medicine practitioners primarily focus on front raise and lateral raise exercises. Although shoulder shrug and IR/ER rotation exercises do produce muscle contraction, it is suggested that they are used on patients in the preliminary stages of rehabilitation. Limitations Only recreational athletes from one Division I university participated in this study. Recruiting recreational and NCAA athletes from multiple institutions across the country would provide a more diverse sample. Variables such as education level, hydration status, and hours of sleep were not controlled in this study. Another limitation was fitness levels of the participants causing them to become fatigued by the final exercise. The exercises were randomized and participants 49 were allowed to rest between sessions which minimized fatigue. Only female recreational athletes were included in this study; therefore, the results can only be generalized to the female population. Future research needs to examine male athletes using the Bodyblade”. These limitations should be addressed and controlled in future studies examining differences in the amount of muscle recruitment in the shoulder when comparing the use of the Bodyblade” in static and rhythmic stabilization positions. Future Research Considerations Future research should examine different positions incorporating the Bodyblade”. These positions should include comparisons between overhead and underarm or prone and supine in order for clinicians to develop a progression for return to play criteria. Although strength is an important aspect of rehabilitation, proprioception must also be considered when observing the effects of rhythmic stabilization exercises on the rotator cuff and scapular stabilizing muscles. Future research should examine the effects of co- activation patterns in order to determine different muscle 50 activation patterns using agonist and antagonist muscle between scapular stabilizers and rotator cuff muscles. Other areas of future interest should include the effects of Bodyblade” size in comparison to subject’s height to arm ratio. Understanding these two factors will assist clinicians in developing more efficient rehabilitation programs and prescribing the most effective Bodyblade”. The current study should be expanded to include post surgical patients, males, and athletes from a variety of sports. This may help generalize the findings of the current study to a larger population. Conclusion This study examined the percentage of reference muscle contraction during eight different exercises across six different shoulder muscles. More specifically, this study observed differences in the amount of muscle recruitment of six muscles in the shoulder comparing the use of the Bodyblade“I during four static and four rhythmic stabilization activities. This was one of the first studies to demonstrate the effects of rhythmic stabilization using Bodyblade” on the rotator cuff muscles in terms of motor unit recruitment. 51 At the present time the four positions revealed a greater percentage of reference contraction while performing rhythmic stabilization exercises compared to static hold activities. In addition, the teres minor produced the greatest percentage of muscle recruitment when compared to anterior deltoid, pectoralis major, serratus anterior, supraspinatus, and infraspinatus during the Bodyblade" activity in the shoulder shrug, front raise, and IR/ER positions. The overall greatest muscle recruitment was produced during the front raise rhythmic stabilization exercise using the Bodyblade”. In the future, studies may be conducted to help broaden the subject population, as well as help develop more effective rehabilitation protocols. 52 BIBLIOGRAPHY Bodyblade.(2004, October 12). 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Reflexive shoulder activation alterations in the shoulder with anterior glenohumeral instability. The.American Jburnal of sports medicine, 32(4), 1013-1021. Powers, S. K., Howley, E. T. (2001). Exercise Physiology: Theory and application to fitness and performance: forth edition. New York, NY. McGraw—Hill Higher Education. 54 Reinoid, M. M., Wikk, K. E., Fleisig, G. S., Zheng, N., Barrentine, S. W., Chmielewski, T., Cody, R. C., Jameson, G. G., & Andrews, J. R. (2004). Electromyographic analysis of the rotator cuff and deltoid musculature during common shoulder external rotation exercises. The JOurnal of Orthopedic and Sports Physical Therapy, 34(7), 385-94. Rizk, T. E., Christopher, R. P., Pinals, R. S., Higgins, A. C. & Frix,R. (1983). Adhesive Capsulitis (Frozen shoulder): A new approach to its management. Physical Medicine and Rehabilitation, 64, 29-33. Sadhukhan, A. K., Goswami, A., Kumar, A., & Gupta, S. (1994). Effects of sampling frequency on EMG power spectral characteristics. Electromyography and Cflinical.Neurophysiology, 34(3), 159-163. Schulte, R. & Warner, C. (2004) Oscillatory devices accelerate proprioceptive training. Biomechanics, 805, 85-91. Signorile, J.F., Lister, J. L., Rossi, G.D, Ma, F., Stoutenburg, M., Adams, J. B., & Tobkin, S. (2005). Electromyographical analysis of scapular stabilizers using Bodyblade, cuff weights and Thera-band resistance. Medicine & Science in Sports & Exercise, 37(5), 8147. Stone, J. A., Partin, N. B., Lueken, J. S., Timm, K. E., & Edward, J. (1994). Upper extremity proprioceptive training. Jburnal of Athletic Training, 29(1), 15-18. Townsend,H., Jobe, F.W., Pink, M., & Perry, J. (1991). Electromyographic analysis of the glenohumeral muscles during baseball rehabilitation programs. The American journal of Sports Medicine, 19:264-272. 55 APPENDICES 56 APPENDIX A UCRIHS Study Approval Form 57 @L E EL a TI.— OFFICE OF REGULATORY AFFAIRS BIOMIICAL .1. HEALTH nsrmmom REVIEW some (area) muumnr RESEARCH usrmmorw. REVIEW some (came) SOCIAL SCIENCE! ‘ auvrorw. I EDUCATION msrrrunom REVEW BOARD (see) 202 Old: Hall East Lanslng. Mlchlgan 48824-1046 517-355-2180 Fax: 517—432-4503 whunanresearchmsuedu 18 & BIRB: lRB@msu.edu CRIRB: grb@msu.§gu 'S U it an affirmative-action uni-opportunity institution. MICHIGAN STATE UNIVERSITY lnitiallRB Application Approval January 16, 2006 T03 John POWELL 105 IM Sports Circle MSU Category: EXPEDITED 2-4 January 12, 2006 January 11, 2007 Re: IRB it 05-951 Approval Date: Expiration Date: Title: BODYBLADE: EFFECTS OF RHYTHMIC STABILIZATION ON ROTATOR CUFF MUSCLES MEASURED BY EMG AMONG FEMALES 18-30. The Institutional Review Board has completed their review of your project I am pleased to advise you that your project has been approved. The committee has found that your research project is appropriate in design. protects the. rights and welfare of human subjects. and meets the requirements of MSU's Federal Wide Assurance and the Federal Guidelines (45 CFR 46 and 21 CFR Part 50). The protection of human subjects in research is a partnership between the IRB and the Investigators. We look forward to working with you as we both fulfill our responsibilities. ' Renewals: IRB approval is valid until the expiration date listed above. If you are continuing your project. you must submit an Application for Renewal application at least one month before explration. If the project ls completed. please submit an Application for Permanent Closure. Revisions: The IRB must review any changes In the project. prior to Initiation of the change. Please submit ' ‘ an Applicatlon for Revlslon to have your changes reviewed. It changes are made at the time of renewal. please Include an Application for Revision with the renewal application. Problems: If Issues should arise during the conduct of the research. such as unanticipated problems. adverse events. or any problem that may Increase the risk to the human subjects. notifythe IRB office promptly. Forms are available to report these issues. Please use the IRB number listed above on any forms submitted which relate to this project. or on any correspondence with the IRB offiCe. Good luck In your research. If we can be of further assistance. please contact us at 517- 355- 2180 or via email at I.RB@msu edu. Thank you for your cooperation. Sincerely. Mira; Gerald S. Schatz. J.D. BIRB Chair 0: Kristen Sutton 3059 Biber St 88 East Lansing, MI 48823 58 @L @ as OFFICE OF REGULATORY- AFFAIRS BIOMEDICAL 8 HEALTH INSTITUTIONAL REVIEW BOARD (BIRB) COMMUNITY RESEARCH Iusrnunomu. REVIEW BOARD (CRIRB) SOCIAL SCIENCEI. BEIIMORALI‘EDucArIOII nsrrrunouru. REVIEW BOARD (sIRa) 202 Old: Hall East Lansing. Mlchlgan 48824-1046 517-355-2180 Fax: 517-432-4503 wwwhumanresearchmsuedu sIRB 8 BIRB: lRB@msu.edu * CRIRB: m’ermsuedu MS U i: an aflirmatr‘te-action equal-oppornmity institution. MICHIGAN STATE UNIVERSITY Revision Application Approval January 24, 2006 _To: John POWELL 105 IM Sports Circle MSU Category: EXPEDITED 2-4 January 24. 2006 January 11. 2007 Re: IRB It 05-951 Revision Approval Date: Project Expiration Date: Title: BODYBLADE: EFFECTS OF RHYTHMIC STABILIZATION ON ROTATOR CUFF MUSCLES MEASURED BY EMG AMONG FEMALES 18-30. The Institutional Review Board has completed their review of your project I am pleased to advise you that the revision has been approved. Thls letter notes approval for the addition of two tasks to the protocol to Improve quallty of data and a revised consent form. The review by the committee has found that your revision is consistent with the continued protection of the rights and welfare of human subjects. and meets the requirements of MSU's Federal Wide Assurance and the Federal Guidelines (45 CFR 46 and 21 CFR Part 50). The protection of human subjects In research Is a ' partnership between the IRB and the Investigators. We look forward to working with you as we both fulfill our responsibilities. Renewals. I RB approval Is valid until the expiration date listed above. If you are continuing your project. you must submit an Application for Renewal application at least one month before expiration If the project is completed. please submit an Appllcatlon for Permanent Closure. Revisions: The I RB must review any changes In the project. prior to Initiation of the change. Please submit an Application for Revision to have your changes reviewed. If changes are made at the time of renewal, please Include an Application for Revision with the renewal application. Problems: If issues should arise during the conduct of the research. such as unanticipated problems, adverse events, or any problem that may Increase the risk to the human subjects. notify the IRB office promptly. Forms are available to report these Issues. Please use the IRB number listed above on any forms submitted which relate to this project. or on any correspondence with the IRB Office. Good luck in your research. If we can be of further assistance. please contact us at 517-355-2180 or via small at IRB@msu.edu. Thank you for your cooperation. Sincerely. 742%.: a— Peter Vasilenko Ill. Ph.D. BIRB Vice Chair c: Kristen Sutton 3059 Biber St 88 East Lansing. MI 48823 59 APPENDIX B Human Subjects Consent Form 60 Body blade: Effects of Rhythmic Stabilizations on Rotator Cuff Muscles Measured by EMG, Among Females Ages 18-30 Informed Consent For questions regarding this study, For questions regarding your rights Please contact: as a research participant, please contact: Dr. John Powell . Peter Vasilenko, Ph.D. Department of Kinesiology Committee on Research Involving Humans Michigan State University Michigan State University Phone: (517)432-5018 202 Olds Hall E-mail: nowelli4@msu.edu or East Lansing, MI 48824 ucrihs@msu.edu Kristen R. Sutton Phone: (517) 355-2180 Graduate Assistant Fax: (517) 432-4503 Michigan State University Email: suttonk4@msu.edu Phone: (517) 333-3768 Work: (517) 353—1655 . The purpose of this study is to Observe the activation of the rotator cufi‘ muscles using a combination of surfaceand intramuscular electromyography while using the Bodyblade in three different shoulder positiOns during static holds and rhythmic stabilization. The Body blade is a rehabilitation tool used for shoulder strengthening. Once the ends begin to move, inertia wants to keep them in motion and it's up to you to resist the blade while moving through a prederternined range of motion. Your participation in this study will consist of one 15 minute session and a second 60 minute session. The first session will be used as a practice session to allow you to become proficient at the Bodyblade. During the second session, you will be asked to return for testing. At that time, a physician will place two fine needle electrodes into each of your teres minor, infraspinatus and supraspinatus. A certified athletic trainer will then place 6 surface electrodes on the pectoralis major, serratus anterior, and anterior deltoid. You will then be asked undergo 6 separate tasks, each lasting approximately 30 seconds. The 6 tasks will be performed using a Bodyblade at three different shoulder positions using both a static hold and rhythmic stabilization. The three different shoulder positions will include: arm by your side moving the blade up and down, mimicking shoulder elevation/depression, the shoulder by your side with the elbow bent to 90 degrees, mimicking intemal/extemal rotation and arm at shoulder height moving the blade perpendicular to your arm. ‘ It is impossible for the risk of injury to be completely eliminated during physical activity. Due to the nature of the test the minor potential for misplacement of the needle may cause damage to neural or vascular sites, possible infection at insertion site, and pain from the needle placement. Measures will be taken during the test to ensure your safety during and after the needle insertion. A resident physician specializing in EMG will insert and remove the needles. A certified athletic trainer will be on hand during all testing sessions. Proper precautions will be made before and after the needle placement to help prevent infection. There will be an easily accessible phone in order to dial for emergency medical services. This' study will contribute to understanding the benefits of the Bodyblade. You will receive training and education about the use of the Bodyblade. All data will be stored in a computer which will have a password and login/user name that must be entered before the data can be accessed. All subjects can be identified by the researchers but will be aggregated in all publications, writings, and journals. Your identity and recorded information will remain confidential. Your privacy will be protected to the maximum extent allowable by law. Participation in this study is completely voluntary. There will be no monetary compensation provided in exchange for participation. In order‘to participate in this study, we need your written consent in'the spaces provided below. You may also discontinue participation at any time without penalty. Your This consent form was approved by the Biomedical and Health Institutional Review Board (BIRB) at Michigan State University. Approved 1/12/06 — valid though 1/11/07. This version supersedes all previous versions. IRB # 05-951 61 participation in this research project will not involve any additional costs to you or your health care insurer. If you are injured as a result of your participation in this research project, Michigan State University will assist you in obtaining emergency care, if necessary, for your research related injuries. If you have insurance for medical care, your insurance carrier will be billed in the ordinary manner. As with any medical insurance, any costs that are not covered or in excess of what are paid by your insurance, including deductibles, will be your responsibility. Financial compensation for lost wages, disability, pain or discomfort is not available. This does not mean that you are giving up any legal rights you may have. You may contact Dr. John Powell with any questions. Any questions concerning participation in this study should be directed to Kristen R. Sutton (517) 333- 3768 or Dr. John Powell (517)432-5018. If you have any additional questions concerning your rights as a volunteer or are dissatisfied at any time with any aspect of this study you may contact-anonymously, if you wish- Peter Vasilenko, PhD, Michigan State University’s Chair of the Committee on Research Involving , Human Subjects by phone: (517) 355-2180, fax: (517)432-4503, e-mail: ucrihs@msu.edu, or regular mail: 202 Olds Hail, East Lansing, MI 48824. Your signature below indicates your voluntary agreement to participate in this study. I, have read and agree to participate in this study as (Please Print Your Name) — described above. (Please Sign Your Name) (Date) This consent form was approved by the Biomedical and Health Institutional Review Board (BIRB) at Michigan State University. Approved 1/12/06 - valid though 1/11/07. This version supersedes all previous versions. IRB # 05-951 62 APPENDIX C Health History Questionnaire 63 Name: Date: Subject ID: Study Questionnaire Sex: Age: Weight: Height: Right arm length: How many times, on average, do you work out per week? Do you currently participate in collegiate or professional sports? Yes D No D Medical History Have you ever had surgery on your shoulder? Yes D No I] If so, right or left shoulder? Have you incurred shoulder problems, is. chronic shoulder pain, previously diagnosed shoulder pathology (impingements, sprains, moderate to severe strains, dislocations, etc.) in the past 6 months? Yes El No C] If so, please describe the injury: Have you ever been diagnosed with shoulder multi- directional instabilities? Yes El No C] If so, right or left shoulder? Have you been diagnosed with a major wrist, hand or elbow problem in the past 6 months? Yes D No C] If so, please describe the injury: Do you have a history of cervical spine injuries? Yes D NO [I If so, please describe the injury: 64 APPENDIX D Descriptive Statistics 65 Descriptive Statistics: Raw Data(Volt*seconds) Table 2: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Anterior Deltoid Mean Std. Exercise N (V*sec) Deviation Shoulder shrug static hold 20 0.038 0.021 Shoulder shrug rhythmic stabilization 20 0.202 0.152 Lateral raise static hold 20 1.170 0.557 Lateral raise rhythmic stabilization ' 20 1.633 0.814 Front raise static hold 20 1.145 0.399 Front raise rhythmic stabilization 20 1.435 0.614 IR/ER static hold 20 0.121 0.098 IR/ER rhythmic stabilization. 20 0.292 0.205 Table 3: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Pectoralis Major Mean Std. Exercise N (V*sec) Deviation Shoulder shrug static hold 20 0.057 0.014 Shoulder shrug rhythmic stabilization 20 0.252 0.108 Lateral raise static hold 20 0.115 0.049 Lateral raise rhythmic stabilization 20 0.252 0.137 Front raise rhythmic stabilization 20 0.406 0.249 Front rhythmic stabilization 20 0.620 0.334 IR/ER static hold 20 0.198 0.067 IR/ER rhythmic stabilization 20 0.463 0.176 66 Table 4: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Serratus Anterior Mean Standard Exercise N (V*sec) Dev Shoulder shrug static hold 20 0.070 0.074 Shoulder shrug rhythmic stabilization 20 0.228 0.213 Lateral raise static hold 20 0.483 0.376 Lateral raise shrug rhythmic stabilization 20 0.343 0.204 Front raise static hold 20 0.287 0.238 Front raise shrug rhythmic stabilization 20 0.563 0.383 IR/ER static hold 20 0.099 0.099 IR/ER shrug rhythmic stabilization 20 0.229 0.264 Table 5: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Supraspinatus Mean Standard Exercise N (V*sec) Dev Shoulder shrug static hold 20 0.382 0.669 Shoulder shrug rhythmic stabilization 20 1.430 0.910 Lateral raise static hold 20 2.500 1.836 Lateral raise rhythmic stabilization 20 3.240 1.826 Front raise static hold 20 1.193 0.789 Front raise rhythmic stabilization 20 2.261 1.179 IR/ER static hold 20 0.221 0.218 IR/ER rhythmic stabilization 20 1.275 1.072 67 Table 6: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Infraspinatus Mean Standard Exercise N (V*sec) Dev Shoulder shrug static hold 20 0.117 0.141 Shoulder shrug rhythmic stabilization 20 1.226 0.831 Lateral raise static hold 20 1.535 0.975 Lateral raise rhythmic stabilization 20 3.818 1.778 Front raise static hold 20 2.860 1.172 Front raise rhythmic stabilization 20 5.269 2.235 IR/ER static hold 20 1.327 0.653 IR/ER rhythmic stabilization 20 4.467 2.113 Table 7: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Teres Minor Mean Standard Exercise N (V*sec) Dev Shoulder shrug static hold 20 0.160 0.249 Shoulder shrug rhythmic stabilization 20 1.114 1.384 Lateral raise static hold 20 0.303 0.520 Lateral raise rhythmic stabilization 20 1.011 1.090 Front raise static hold 20 0.442 0.537 Front raise rhythmic stabilization 20 1.713 1.539 IR/ER static hold 20 0.507 0.836 IR/ER rhythmic stabilization 20 1.782 1.839 68 Table 8: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Shoulder Shrug Position. Mean Std. Muscle N (V*sec) Deviation Static Hold 20 0.038 0.021 AD Rhythmic Stabilization 20 0.202 0.152 Static Hold 20 0.057 0.014 PM Rhythmic Stabilization 20 0.252 0.108 Static Hold 20 0.070 0.074 SA Rhythmic Stabilization 20 0.228 0.213 Static Hold 20 0.382 0.669 SS Rhythmic Stabilization 20 1.430 0.910 Static Hold 20 0.117 0.141 IS Rhythmic Stabilization 20 1.226 0.831 Static Hold 20 0.160 0.249 TM Rhythmic Stabilization 20 1.114 1.384 Table 9: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise Lateral Raise Position Muscles N Mean Std. (V*sec) Deviation AD Static Hold 20 1.170 0.557 Rhythmic Stabilization 20 1.633 0.814 PM Static Hold 20 0.115 0.049 Rhythmic Stabilization 20 0.252 0.137 SA Static Hold 20 0.483 0.376 Rhythmic Stabilization 20 0.343 0.204 SS Static Hold 20 2.500 1.836 Rhythmic Stabilization 20 3.240 1.826 IS Static Hold 20 1.535 0.975 Rhythmic Stabilization 20 3.818 1.778 TM Static Hold 20 0.303 0.520 Rhythmic Stabilization 20 1.011 1.090 69 Table 10: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise Front Raise Position Muscles N Mean Std. (V*sec) Deviation AD Static Hold 20 1.145 0.399 Rhythmic Stabilization 20 1.435 0.614 PM Static Hold 20 0.406 0.249 Rhythmic Stabilization 20 0.620 0.334 SA Static Hold 20 0.287 0.238 Rhythmic Stabilization 20 0.563 0.383 SS Static Hold 20 1.193 0.789 Rhythmic Stabilization 20 2.261 1.179 IS Static Hold 20 2.860 1.172 Rhythmic Stabilization 20 5.269 2.235 TM Static Hold 20 0.442 0.537 Rhythmic Stabilization 20 1.713 1.539 Table 11: Comparison of Means between Static Hold Exercise and Rythmic Stabilization Exercise IR/ER Position Muscles N Mean Std. (V*sec) Deviation AD Static Hold 20 0.121 0.098 Rhythmic Stabilization 20 0.292 0.205 PM Static Hold 20 0.198 0.067 Rhythmic Stabilization 20 0 . 463 0 . 176 SA Static Hold 20 0.099 0.099 Rhythmic Stabilization 20 0 . 229 0 . 264 SS Static Hold 20 0.221 0.218 Rhythmic Stabilization 20 l . 275 l . 072 IS Static Hold 20 1.327 0.653 Rhythmic Stabilization 20 4 . 467 2 . 113 TM Static Hold 20 0.507 0.836 Rhythmic Stabilization 20 l . 782 l . 839 Descriptive Statistics (% of MVC) 70 Table 12: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Shoulder Shrug Position Shoulder Shrug Muscles SH Std Dev RS Std Dev Anterior deltoid 1.09 0.59 5.48 4.53 Pectoralis major 6.08 2.65 27.35 15.68 Serratus anterior 9.09 4.26 30.89 18.16 Supraspinatus 6.97 7.20 37.11 41.10 Infraspinatus 1.47 1.99 14.22 8.57 Teres minor 6.28 4.43 74.23 114.71j Table 13: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Lateral Raise Position Lateral Raise Muscles SH Std Dev RS Std Dev Anterior deltoid 32.66 13.96 46.41 24.74 Pectoralis major 12.51 7.57 30.18 26.15 Serratus anterior 37.97 18.42 64.17 32.59 Supraspinatus 41.45 13.58 66.13 38.55 Infraspinatus 17.83 10.84 44.01 22.53 Teres minor 11.41 10.07 51.32 48.93 Table 14: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise in Front Raise Position Front Raise Muscle SH Std Dev RS Std Dev Anterior deltoid 33.32 14.32 43.69 28.12 Pectoralis major 44.98 31.63 70.89 56.07 Serratus anterior 47.95 20.65 78.09 41.23 Supraspinatus 41.45 10.24 52.32 38.54 Infraspinatus 35.81 19.83 63.71 35.71 Teres minor 22.41 25.21 101.21 139.27 71 Table 15: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise’in IR/ER Position Internal/External Rotation Muscle SH Std Dev RS Std Dev Anterior deltoid 4.54 5.98 8.52 7.39 Pectoralis major 20.70 8.67 54.54 37.51 Serratus anterior 12.52 5.64 28.49 14.98 Supraspinatus 5.46 6.57 36.89 57.39 Infraspinatus 15.45 6.19 51.83 25.28 Teres minor 13.10 9.59 78.65 112.75 Table 16: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Anterior Deltoid SH RS Mean Std Mean Std Exercises (% MVC) IDeviation (% MVC) IDeviation Shoulder Shrug 1.09 0.59 5.48 4.53 Lateral Raise 32.66 13.96 46.41 24.74 Front Raise 33.32 14.32 43.69 28.12 Internal/External Rotation 4.54 5.98 8.52 7.39 Table 17: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Pectoralis Major SH RS Mean Std Mean Std Exercises (% MVC) Deviation (% MVC) Deviation Shoulder Shrug 6.08 2.65 27.35 15.68 Lateral Raise 12.51 7.57 30.18 26.15 Front Raise 44.98 31.63 70.89 56.07 Internal/External Rotation 20.70 8.67 54.54 37.51 72 Table 18: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Serratus Anterior SH RS Mean Mean Exercises (% MVC) Std Dev (% MVC) Std Dev Shoulder Shrug 9.09 4.26 30.89 18.16 Lateral Raise 37.97 18.42 64.17 32.59 Front Raise 47.95 20.65 78.09 41.23 Internal/External Rotation 12.52 5.64 28.49 14.98 Table 19: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Supraspinatus SH RS Exercises Mean Std Dev Mean Std Dev Shoulder Shrug 6.97 7.20 37.11 41.10 Lateral Raise 41.45 13.58 66.13 38.55 Front Raise 41.45 10.24 52.32 38.54 Internal/External Rotation 5.46 6.57 36.89 57.39 Table 20: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Infraspinatus SH RS Exercises Mean Std Dev Mean Std Dev Shoulder Shrug 1.47 1.99 14.22 8.57 Lateral Raise 17.83 10.84 44.01 22.53 Front Raise 35.81 19.83 63.71 35.71 Internal/External Rotation 15.45 6.19 51.83 25.28 Table 21: Comparison of Means between Static Hold Exercise and Rhythmic Stabilization Exercise by the Teres Minor SH RS Exercises Mean Std Dev Mean Std Dev Shoulder Shrug 6.28 4.43 74.23 114.71 Lateral Raise 11.41 10.07 51.32 48.93 Front Raise 22.41 25.21 101.21 139.27 Internal/External Rotation 13.10 9.59 78.65 112.75 73 Pair wise Comparisons Table 22: Pair wise Comparison for Shoulder Shrug with Static Hold Mean Muscles Diff Sig. 95% CI Lower Upper Bound Bound AD PM -4.99 0.000 -6.21 —3.78 AD SA -8.00 0.000 -10.06 -5.94 AD SS -5.88 0.002 -9.21 -2.55 AD IS -0.38 0.406 —l.31 0.55 AD TM -5.19 0.000 -7.11 -3.27 PM SA —3.01 0.003 -4.87 -l.14 PM SS -0.89 0.630 -4.68 2.90 PM IS 4.62 0.000 2.90 6.34 PM TM -0.20 0.874 -2.75 2.35 SA SS 2.12 0.269 -1.77 6.01 SA IS 7.62 0.000 5.25 9.99 SA TM 2.81 0.058 -0.11 5.73 SS IS 5.50 0.005 1.92 9.09 SS TM 0.69 0.724 -3.34 4.72 IS TM -4.81 0.000 -6.93 -2.70 74 Table 23: Pair wise Comparison for Shoulder shrug with Rhythmic Stabilization Muscles Mean Diff Sig. 95% CI Lower Upper Bound Bound AD PM —21.870 .000 —28.91 -14.83 AD SA —25.406 .000 —34.27 —16.54 AD SS -31.632 .003 —50.95 -12.31 AD IS —8.733 .000 -12.34 -5.13 AD TM -68.746 .015 -122.53 -14.96 PM SA -3.536 .379 -11.76 4.68 PM SS -9.762 .240 -26.61 7.08 PM IS 13.137 .000 6.75 19.52 PM TM ~46.876 .071 -98.21 4.45 SA SS -6.225 .345 -19.68 7.23 SA IS 16.674 .001 8.32 25.03 SA TM —43.340 .089 —93.86 7.19 SS IS 22.899 .018 4.31 41.49 SS TM -37.114 .073 -78.05 3.82 18 TM -60.013 .029 -113.04 -6.98 75 Table 24: Pair wise Comparison for Lateral Raise with Static Hold Muscles Mean Diff Sig. 95% CI Lower Upper Bound Bound AD PM 20.15 0.000 14.67 25.64 AD SA -5.31 0.151 —12.74 2.12 AD SS -8.79 0.085 -18.93 1.35 AD IS 14.83 0.000 7.74 21.92 AD TM 21.25 0.000 14.04 28.46 PM SA -25.46 0.000 -32.94 ‘fi17.97 PM SS -28.94 0.000 -36.91 -20.97 PM IS -5.32 0.028 —10.00 -0.63 PM TM 1.10 0.635 —3.68 5.88 SA SS -3.48 0.558 -15.69 8.72 SA IS 20.14 0.000 12.28 28.00 SA. TM 26.56 0.000 17.82 35.30 SS IS 23.62 0.000 15.23 32.02 SS TM 30.04 0.000 22.10 37.99 IS TM 6.42 0.026 0.86 11.98 76 Table 25: Pair wise Comparison for Lateral Raise with Rhythmic Stabilization Muscles Mean Diff Sig. 95% CI Lower Upper Bound Bound AD PM 16.231 .004 5.76 26.70 AD SA -17.760 .019 -32.20 -3.33 AD SS -19.719 .043 -38.76 —0.68 AD IS 2.408 .691 -10.07 14.88 AD TM -4.901 .617 -25.09 15.29 PM SA -33.992 .000 -44.86 -23.12 PM SS -35.951 .000 -50.42 -21.48 PM IS -13.823 .013 —24.41 -3.23 PM TM -21.133 .025 -39.30 -2.96 SA SS -1.959 .763 -15.37 11.45 SA IS 20.168 .012 4.90 35.44 SA TM 12.859 .267 -10.68 36.40 SS IS 22.128 .027 2.82 41.44 SS TM 14.818 .248 -11.23 40.86 IS TM -7.309 .468 -27.97 13.35 77 Table 26: Pair wise Comparison for Front Raise with Static Hold Muscle Mean Diff Sig. 95% CI Lower Upper Bound Bound AD PM -11.66 .073 -24.50 1.18 AD SA -14.63 .003 —23.73 -5.53 AD SS 10.88 .011 2.79 18.97 AD IS -2.49 .604 -12.40 7.41 AD TM 10.91 .050 0.00 21.81 PM SA -2.97 .675 -17.58 11.64 PM SS 22.54 .014 5.20 39.88 PM IS 9.17 .242 -6.72 25.05 PM TM 22.57 .006 7.22 37.92 SA SS 25.51 .000 15.71 35.31 SA IS 12.14 .025 1.68 22.59 SA TM 25.54 .001 12.35 38.73 SS IS -13.37 .003 -21.61 -5.14 SS TM 0.03 .996 -12.40 12.46 IS TM 13.40 .047 0.22 26.58 78 Table 27: Pair wise Comparison for Front Raise with Rhythmic Stabilization Muscles Mean Diff Sig. 95% CI Lower Upper Bound Bound AD PM —27.20 0.008 —46.50 -7.90 AD SA -34.41 0.002 -53.92-14.89 AD SS -8.64 0.329 -26.70 9.43 AD IS -20.02 0.009 -34.35 ~5.69 AD TM -57.53 0.047 -114.12 -0.94 PM SA -7.20 0.495 -28.87 14.46 PM SS 18.56 0.049 0.12 37.00 PM IS 7.18 0.479 —13.64 28.00 PM TM -30.33 0.266 -85.66 125.01 SA SS 25.77 0.001 11.72 39.81 SA IS 14.38 0.103 -3.19 31.95 SA TM —23.12 0.434 —83.65 37.41 SS IS -11.38 0.181 -28.53 5.? SS TM —48.89 0.108 -109.48 11.70 IS TM -37.50 0.213 -98.43 23.42 79 Table 28: Pair wise Comparison for IR/ER with Static Hold Muscles Mean Diff 95% CI Lower Upper Bound Bound AD PM —16.16 .000 -20.79 -11.52 AD SA -7.98 .000 -10.95 -5.01 AD SS -0.92 .646 -5.08 3.23 AD IS -10.91 .000 -13.51 -8.31 AD TM -8.56 .001 —13.04 -4.08 PM SA 8.18 .001 4.02 12.34 PM SS 15.23 .000 10.67 19.79 PM IS 5.25 .033 0.46 10.04 PM TM 7.60 .008 2.21 12.99 SA SS 7.05 .000 3.55 10.55 SA IS -2.93 .109 —6.58 0.72 SA TM -0.58 .765 -4.59 3.43 SS IS -9.98 .000 -14.20 -5.76 SS TM -7.64 .015 -13.61 -1.66 IS TM 2.35 .346 -2.73 7.43 80 Table 29: Pair wise Comparison for IR/ER with Rhythmic Stabilization Exercise 95% Confidence Interval for Muscles Mean Diff Sig. Difference Lower Upper Bound Bound AD PM —46.02 0.000 -62.06 -29.99 AD SA -19.97 0.000 -28.01 -11.93 AD SS —28.37 0.039 -55.22 -1.52 AD IS -43.31 0.000 -54.57 -32.04 AD TM -70.13 0.009 -120.91 -19.36 PM SA 26.05 0.003 9.89 42.21 PM SS 17.66 0.164 -7.87 43.18 PM IS 2.71 0.650 —9.61 15.04 PM TM -24.11 0.258 -67.41 19.19 SA SS -8.39 0.459 -31.63 14.85 SA IS -23.34 0.000 -33.22 —13.45 SA TM -50.16 0.058 -102.30 1.98 SS IS -14.94 0.183 -37.59 7.71 SS TM -41.77 0.121 -95.65 12.12 18 TM —26.82 0.273 -76.55 22.91 81 Table 30: Repeated Measures ANOVA for Delayed Comparing Four different Positions during Static Hold and Rhythmic Stabilization across Six Muscles Exercises SS df MS F P SSSH 1020.46 5.00 204.09 12.02 0.000 SSBB 57009.49 5.00 11401.90 5.32 0.000 LRSH 17744.84 5.00 3548.97 25.73 0.000 LRBB 18072.38 5.00 3614.48 5.33 0.000 FRSH 11708.99 5.00 2341.80 6.67 0.000 FRBB 41360.08 5.00 8272.02 2.63 0.028 IRERSH 3746.63 5.00 749.33 17.26 0.000 IRERBB 58379.93 5.00 11675.99 4.82 0.001 Table 31: Repeated Measures ANOVA for Delayed Eight Exercises Comparing Six Muscles across Eight Exercises Muscles SS 'df MS F P AD 50093.95 7.00 7156.28 50.61 .000 PM 67544.94 7.00 9649.28 19.33 .000 SA 80283.97 7.00 11469.14 49.20 .000 SS 62385.35 7.00 8912.19 13.37 .000 IS 65273.55 7.00 9324.79 42.84 .000 TM 186844.58 7.00 26692.08 5.92 .000 82