Tennis-specific extension of the International Olympic Committee consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020.

The IOC has proposed standard methods for recording and reporting of data for injury and illness in sport. The IOC consensus statement authors anticipated that sport-specific statements would provide further recommendations. This statement is the tennis-specific extension of the partner IOC statement. The International Tennis Federation Sport Science and Medicine Committee, in collaboration with selected external experts, met in June 2019 to consider athlete health monitoring issues specific to tennis. Once the IOC consensus statement was finalised, the tennis-specific consensus was drafted and agreed on by the members over three iterations. Compared with the IOC consensus statement, the tennis consensus contains tennis-specific information on injury mechanism, mode of onset, injury classification, injury duration, capturing and reporting exposure, reporting risk and study population. Our recommendations apply to able-bodied as well as wheelchair tennis players. Where applicable, specific recommendations are made for wheelchair tennis.

Kerlan-Jobe Orthopaedic Clinic (KJOC) score and scapular dyskinesis test in collegiate baseball players.

BACKGROUND: The Kerlan-Jobe Orthopaedic Clinic (KJOC) score has been used to describe various parameters of throwing shoulder and elbow function for the return to play after a long period of rehabilitation, such as after ulnar collateral ligament reconstruction. No study has yet to identify how scapular dyskinesis (SD) in baseball players affects the KJOC score. This study investigated the relationship of the KJOC score to SD evaluated in collegiate baseball players with and without upper extremity injury. MATERIALS AND METHODS: The study participants were 30 male collegiate baseball players (13 pitchers) belonging to the National Collegiate Athletic Association D-I conference. Participants were assessed with the KJOC instrument in the beginning (PRE) and end (POST) of the season. The SD test was conducted (PRE) in shoulder flexion to identify SD RESULTS: The mean value of KJOC score was significantly less in POST than that of PRE for the pitchers with SD (89.3 and 60.5, respectively; P = .001), whereas no difference was found in the KJOC score between PRE and POST for the pitchers without SD. For the position players, no difference in the mean value of KJOC score was found between PRE and POST, regardless of SD. CONCLUSION: The results of this study provide evidence that collegiate baseball pitchers with mild SD may have lower KJOC scores, particularly setup or relief pitchers.

Adaptation of muscle activity in scapular dyskinesis test for collegiate baseball players.

BACKGROUND: The characteristics of scapular muscle activities in elevation and descent exercises have yet to be elucidated to assess scapular dyskinesis. The purpose of this study was to identify the adaptation of electromyograph (EMG) activities of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and anterior deltoid (AD) muscles with different weight loads in flexion (FLX) and abduction (ABD) in collegiate baseball players. MATERIALS AND METHODS: Twenty eight individuals, including 13 pitchers, were tested. Normalized EMG signals for the UT, LT, SA, AD muscle of the both the dominant (DOM) and nondominant (NON) side were blocked at every 1 second during each of the exercises. A 3-way repeated analysis of variance design was used to identify differences in the mean values between DOM and NON and between FLX and ABD for DOM. RESULTS: The mean EMG value of the UT in the DOM was significantly less than that of the NON for all joint angles (P < .01), whereas the mean EMG value of the LT in the DOM was significantly greater than that of the NON (P < .01). In contrast, no difference in the SA EMG activity was determined between DOM and NON. However, the mean EMG value of SA in FLX was significantly greater than in ABD (P < .01). CONCLUSION: This study identified an apparent adaptation of scapular muscle activities in the currently advocated scapular dyskinesis test for healthy active overhead athletes who are vulnerable to shoulder pathologies.

Tennis injuries: epidemiology, pathophysiology, and treatment.

Tennis places high loads on the joints of players, with supraphysiologic forces being generated at the shoulder and elbow hundreds of times per match. Acute injuries tend to affect the lower extremity; chronic injuries usually involve the upper extremity. Commonly encountered upper extremity conditions include rotator cuff injury, internal impingement, superior labral tears, and epicondylitis of the elbow. Serving is the most strenuous stroke in tennis, with the highest peak muscle activity in the shoulder and forearm occurring during this stroke. The kinetic chain links upper extremity, lower extremity, and core muscle segments by transmitting coordinated activation and motion; in this regard, any pathologic process that disturbs the groin, hip, and abdominal musculature can further result in an increased risk of injury to the shoulder and upper extremity. Evolution in equipment and in play surfaces has also affected the type and frequency of injuries. Prevention programs that address the muscular imbalances throughout the kinetic chain may help reduce the incidence of both acute and chronic injuries experienced by tennis athletes.

Reproducibility and Validity of the Kerlan-Jobe Orthopedic Clinic Shoulder and Elbow Score (Japanese Version).

BACKGROUND: The Kerlan-Jobe Orthopedic Clinic (KJOC) questionnaire is a self-reported performance and functional assessment tool with good reliability and validity for overhead athletes with shoulder and elbow injuries. This study aimed to develop a Japanese version of the KJOC (J-KJOC) to clarify its reproducibility and validity for use by Japanese university baseball players. METHODS: The J-KJOC was translated according to the guidelines for cross-cultural adaptation. A total of 88 university baseball players completed the J-KJOC and the Quick-Disabilities of the Arm, Shoulder, and Hand (Q-DASH) questionnaires. Thirty players completed the J-KJOC two times after a median interval of two weeks. We assessed the absolute reliability, construct validity, internal consistency, and test-retest reliability. RESULTS: Cronbach's alpha coefficients ranged from 0.88 and the intraclass correlation coefficient for the total score was 0.91. A fixed bias was absent in the J-KJOC scores (mean difference: -2.2, 95% CI: -4.8 to 0.5). Furthermore, the J-KJOC score was correlated with the Q-DASH-disability/symptom (r = -0.60, p<0.01) and Q-DASH-sports/music (r = -0.63, p<0.01) scores but not correlated with the Q-DASH-work score (r = -0.11, p = 0.316). CONCLUSIONS: The J-KJOC questionnaire demonstrated good reproducibility and validity for assessing upper arm performance in Japanese university baseball players. The results of this study support the use of the J-KJOC for Japanese-speaking baseball players. Further research using this instrument on other types of overhead athletes is needed to determine its wider utility in sports medicine applications.

Effects of a compression garment on shoulder external rotation force outputs during isotonic contractions.

The use of compression garments (CGs) has been advocated for performance enhancement and recovery in athletes. The effect of a CG on humeral rotation motor control has not been previously tested. The purpose of this study was to examine the isotonic contraction of external rotation (ER) of the glenohumeral joint at different force outputs to determine the effect of wearing a long sleeve CG on muscular performance. Twelve male college tennis players and 12 male college soccer players were tested for ER of the dominant shoulder during both concentric and eccentric isotonic contractions. The subjects performed 5 consecutive repetitions of both concentric and eccentric ER at 20-30% and 40-50% of maximum voluntary isometric contraction (MVIC) intensities. All subjects were tested with and without CG as well as with and without ongoing visual feedback information (OVFI). The order of CG wearing and the presence of OVFI were randomly assigned across all subjects. The results indicated a significant 3-way interaction between CG wearing and OVFI across 2 loads. Specifically, significantly different mean value of the completion time was found between OVFI and no-OVFI without CG wearing at 40-50% of MVIC, whereas no difference in the completion time was found with and without OVFI with CG wearing. Taken together, with CG wearing, athletes may have ER at 40-50% of MVIC more readily maintained by peripheral feedback without visuomotor control imposed on force outputs as compared without CG wearing.

Effect of Scapular Retraction on Lower Trapezius, Infraspinatus, and Deltoid Muscle Electromyographic Activity During the Side-Lying Abduction Exercise.

Background: The lower trapezius (LT) muscle, which stabilizes the scapula posteriorly during arm elevation, has been interesting to both clinicians and researchers for its importance in throwing-related shoulder rehabilitation and injury prevention. Purpose: The purpose of this study was to investigate the electromyographic activity of the LT and other relevant muscles during scapular and shoulder activities in the side-lying position. Methods: Twenty collegiate baseball players volunteered to participate in this study. Electromyographic (EMG) output of the lower trapezius, infraspinatus, posterior deltoid, middle deltoid, serratus anterior, and upper trapezius muscles were collected. All the subjects performed isometric resistance exercises in four arm positions: 0° horizontal abduction from the coronal plane (NEUT) with protraction (NEUT-PRO), 15° horizontal adduction from the coronal plane (HADD) with protraction (HADD-PRO), and NEUT with retraction (NEUT-RET), and HADD-RET in a side-lying isometric abduction exercise with two external loads: a 9.1 kg dumbbell and 40% of the manual muscle test (MMT). The subjects also performed two more isometric resistance exercises: supine protraction and side-lying external rotation (ER) of the glenohumeral (GH) joint in GH adduction at 90° of GH ER or with as much ER as possible. All raw EMG data were normalized to maximal voluntary isometric contraction (% MVIC) of the corresponding muscle. Results: LT activity was significantly greater in HADD-RET with 9.1 kg than that of HADD-PRO (p < 0.001) (55 vs 21% MVIC) while middle deltoid muscle activity was significantly decreased in both NEUT and HADD-RET compared to that of NEUT and HADD-PRO (p < 0.001). In contrast, IS muscle activity was significantly increased in HADD-RET with 9.1 kg compared with that 40% MMT (p < 0.001) (41 vs 22% MVIC). Conclusion: LT activity was modulated by changes in scapulothoracic and glenohumeral joint positioning during a side-lying isometric abduction exercise. These findings may help clinicians to select exercises to improve scapular muscle balance ratios during rehabilitation of the shoulder complex. Level of Evidence: Level 3b, Controlled laboratory study.

Reliability of scapular classification in examination of professional baseball players.

BACKGROUND: Clinically evaluating the scapulothoracic joint is challenging. To identify scapular dyskinesis, clinicians typically observe scapular motion and congruence during self-directed upper extremity movements. However, it is unclear whether this method is reliable. QUESTIONS/PURPOSES: We therefore determined the interrater reliability of a scapular classification system in the examination of professional baseball players. METHODS: Seventy-one healthy uninjured professional baseball players between the ages of 18 and 32 years volunteered to participate. We used a digital video camera to film five repetitions of scapular plane elevation while holding a 2-pound weight. Four examiners then independently classified the motions on video into one of four types. Interrater reliability analysis using the kappa (k) statistic was performed for: (1) classifying each scapula into one of the four types; (2) classifying each scapula as being abnormal (Types I-III) or normal (Type IV); and (3) classifying both scapula as both being symmetric (both normal or both abnormal) or asymmetric (one normal, one abnormal). RESULTS: We found low reliability for all analyses. In classifying each scapula as one of the four types, reliability was k = 0.245 for the left limb and k = 0.186 for the right limb. When considering the dichotomous classifications (abnormal versus normal), reliability was k = 0.264 for left and k = 0.157 for right. For bilateral symmetry/asymmetric, reliability was k = 0.084. CONCLUSION: We found low reliability of visual observation and classification of scapular movement. CLINICAL RELEVANCE: Current evaluation strategies for evaluating subtle scapular abnormalities are limited. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

A comparison of teres minor and infraspinatus muscle activation in the prone position.

BACKGROUND: The electromyography (EMG) activity of the teres minor (TMi) and infraspinatus (IS) muscle has been demonstrated to vary depending on the arm position, such as in the coronal or scapular position, during intervention exercises. This may be reflected by different EMG activities demonstrated between the TMi and IS muscle during the acceleration and deceleration phases of the pitching motion. Tenderness in the scapular attachment site of the TMi muscle is often seen in baseball pitchers after pitching but not the attachment site of the IS muscle. However, few studies have investigated an interaction between TMi and IS muscle activity across different resistance exercises with different arm positions. The purpose of this study was to identify the feature of TMi and IS muscle activity in the presence of manual resistance applied in the prone position. METHODS: Eighteen collegiate baseball players volunteered their participation. Raw EMG amplitudes of the TMi, IS, posterior deltoid, middle deltoid, and upper trapezius muscles on the dominant shoulder were measured during intervention exercises. All subjects performed manual isometric resistance exercises: horizontal abduction (HABD) and external rotation (ER) of the glenohumeral joint with 40% of the manual maximum strength test in prone. The subjects also performed each of the HABD and ER resistance exercises with the arm actively positioned at 0° and 45° of ER of the glenohumeral joint in the coronal and scapular planes. RESULTS: Both TMi and IS muscle activities significantly increased with the arm positioned at 45° of ER compared with 0° of ER regardless of the exercise (P < .05). TMi activity was significantly greater with HABD resistance than IS muscle activity regardless of the arm positions, whereas it was significantly less with ER resistance than IS muscle activity. CONCLUSION: The findings of this study indicated that the TMi and IS muscles were most highly activated during the HABD resistance with the arm actively positioned at 45° of ER in the coronal plane. The results of this study have clinical implications regarding the careful selection of arm position in both exercise and clinical examination for the TMi and IS muscles.

Rehabilitation and Return to Sport Following Elbow Injuries.

Elbow injuries are frequently seen in throwing and overhead athletes. This review provides a framework for diagnosis, treatment, and particularly rehabilitation of common elbow pathologies, including ulnar collateral ligament injury, valgus extension overload, and medial and lateral epicondylitis. Advanced rehabilitation facilitates complete return to functional sport-specific activity and is based on objective criteria. As diagnostic and therapeutic modalities improve our understanding of elbow pathologies in the athletic patient, continued research will further elucidate objective evidence-based rehabilitation techniques.

Can the Scapular Dyskinesis Test be Associated with Throwing Related Injuries During the Course of Collegiate Baseball Seasons?

Background: A pattern of scapular dyskinesis on the dominant side has been demonstrated to be associated with a decrease in throwing arm conditions identified by a self-report outcome assessment in collegiate baseball pitchers during the course of a single season. However, it is unclear if symptomatic shoulders in baseball pitchers may be associated with the presence of scapular dyskinesis. Purpose: To study the relationship between the presence of scapular dyskinesis and throwing-related injury in collegiate baseball pitchers during each respective course of up to four subsequent seasons. Methods: A single Division 1 National Collegiate Athletic Association team participated in this study over a four-year-period. The scapular dyskinesis test was implemented during the preseason for baseball pitchers. Players were followed throughout each respective season to track the incidence of throwing-related upper extremity injuries. Results: A total of 36 collegiate baseball pitchers (height: 185.3 ± 5.6 cm, weight: 88.8 ± 7.8 kg, age: 20.0 ± 1.5 years) consisting of 57 pitcher seasons were followed in this study, in which 18 pitchers remained with the team for more than one year. Twenty-seven of the 57 pitchers were classified as having scapular dyskinesis demonstrated at around 90° of shoulder flexion on the throwing side. Five injuries (13.2% of a total of 38 injuries) were diagnosed as throwing-related shoulder injuries during the course of the intercollegiate baseball seasons. Four of the five throwing-related shoulder injuries occurred in pitchers who had scapular dyskinesis on their dominant side. Consequently, the odds ratio was 5.04 for the collegiate pitchers with scapular dyskinesis on the throwing arm side associated with a throwing-related shoulder injury compared to those with no scapular dyskinesis (p = 0.16). No relationship was identified between scapular dyskinesis on the throwing arm side and throwing-related elbow injury. Eighty-one percent of the scapular dyskinesis test results were not changed on the throwing side from the previous to the following year for those 18 pitchers who were followed for more than one season, whereas 42.9% of the results remained unchanged on the non-throwing side. Conclusion: The results suggest that collegiate baseball pitchers with dominant arm scapular dyskinesis likely are at increased risk of throwing-related shoulder injury. Level of evidence: Level 2, Prospective Cohort Study.

Age and Gender Differences in Injuries and Risk Factors in Elite Junior and Professional Tennis Players.

BACKGROUND: Elite tennis athletes experience injuries throughout the entire body. Impairments in trunk stability, lower limb flexibility, and hip range of motion (ROM) are modifiable risk factors that can impact injuries and performance. Information on nonmodifiable risk factors such as age and gender is limited. The purpose of this investigation was to provide information on risk factors to direct clinical decision-making and injury prevention and rehab programming in this population. HYPOTHESIS: Prevalence and location of injuries will differ by age group and gender. Trunk stability, lower limb flexibility, and hip ROM will differ by age group and gender. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: A de-identified database (n = 237; females = 126) from the United States Tennis Association High Performance Profile (HPP) 2014-2015 was used for the analysis. Subjects were elite junior and professional tennis players (mean age 14.6 [range, 9-27] years). The HPP is a tennis-specific assessment and questionnaire that includes retrospective information on injury history. Subjects were categorized by injury, gender, and age. Injury locations were classified by region. Trunk stability measures included drop vertical jump (DVJ), single-leg squat, and prone and side planks. Lower limb measures included hamstring, quadriceps and hip flexor flexibility, and hip rotation ROM. RESULTS: A total of 46% of athletes reported an injury. Significant differences were found for injury prevalence and location by age group. Adolescent athletes (age 13-17 years) had more trunk injuries, while adult athletes (age ≥18 years) had more lower limb injuries. Adolescent athletes performed worse on DVJ, dominant side plank, and hamstring flexibility compared with young (age ≤12 years) and adult athletes. Significant gender differences in hip ROM included internal rotation on both the dominant and nondominant sides. CONCLUSION: Impairments in trunk stability, lower limb flexibility, and hip rotation ROM may affect both health and performance outcomes in this population. Elite tennis athletes may benefit from additional off court programming to address trunk and lower limb impairments. CLINICAL RELEVANCE: Adolescent elite tennis athletes may be at higher risk of trunk injuries. Age, gender, injury history, and impairments should be considered with all assessments and programming.

Electromyography activity of the teres minor muscle with varying positions of horizontal abduction in the quadruped position.

BACKGROUND: The teres minor (TMi) muscle exposed relatively high activity during the acceleration and deceleration phases of the throwing motion, compared with the infraspinatus muscle. However, few studies have identified TMi muscle activity in intervention exercises. The purpose of this study was to investigate TMi muscle activities in different horizontal adduction positions in the quadruped horizontal abduction exercise. This study hypothesized that TMi muscle activity would differ in response to resistance application across different horizontal adduction positions. MATERIALS AND METHODS: Nineteen collegiate baseball players volunteered their participation. Raw electromyography activity of the TMi muscle along with 7 different muscles attached to the scapula on the dominant-side were collected, and normalized by each of the corresponding maximum voluntary isometric contractions. All subjects performed manual isometric resistance horizontal abduction exercises at 90° and 135° of abduction with 3 horizontal adduction angles in the quadruped position: 1) coronal, 2) scapular, and 3) sagittal plane. Electromyography data were also collected from rhythmical concentric contraction of horizontal abduction at 90° of abduction in the quadruped position. RESULTS: TMi muscle activity was significantly greater with the arm positioned in the coronal plane than that of the scapular and sagittal planes (41, 26, and 17% maximum voluntary isometric contraction, respectively) (P < .05). CONCLUSION: The present study demonstrated that TMi muscle activity varied depending on horizontal adduction positions.

Descriptive Strength and Range of Motion in Youth Baseball Players.

BACKGROUND: There are limited studies reporting descriptive strength and range of motion in youth baseball players 12 years of age or younger. PURPOSE: To establish normative data for external (ER) and internal (IR) rotation range of motion (ROM), total arc range of motion (TROM), and isometric rotator cuff strength in youth baseball players, and to compare between the dominant throwing arm (D) to the non-dominant arm (ND). STUDY DESIGN: Cross-sectional. METHODS: Patient population included 50 (5 to 12-year-old) uninjured, healthy athletes. ROM measurements were performed preseason using a goniometer for IR and ER in the supine position with the shoulder in 90 degrees of abduction (abd) with scapular stabilization. Isometric strength measurements for IR and ER were collected in both neutral and 90 degrees (deg) of abduction with the use of a hand-held dynamometer and recorded in pounds (lbs) utilizing a "make" test. Descriptive statistics were obtained for all measures. RESULTS: All data were analyzed as a single group (average age: 9.02). No significant difference in average total arc of PROM (ER+IR=Total Arc) on the D side compared to the ND side (136.7 ± 12.7 deg vs. 134.3 ± 12.3 deg). There were statistically significant differences between ER ROM (102.2 ± 7.7 deg vs. 96.8 ± 7.4 deg) and IR ROM (34.4 ± 9.0 deg vs. 37.5 ± 9.5 deg) between D versus ND arms (p= .000, .006 respectively). Mean ER strength in neutral (13.6 ± 3.4 and 12.8 ± 3.6 lbs) and 90 deg abduction (12.3 ± 3.4 and 12.5 ± 4.3 lbs) did were not significantly different between D and ND arms, respectively. Mean IR strength in neutral (18.0 ± 6.0 and 15.7 ± 4.7 lbs) and 90 deg abd (16.4 ± 5.6 and 15.0 ± 5.7 lbs) was significantly greater in the D arm vs ND arm, respectively (p=.000, .001). CONCLUSION: These data can provide descriptive information for clinicians who treat very young baseball players. These data show sport specific adaptations occur at very young ages (5-12) and are similar to prior reports on adolescent, high school and professional baseball players regarding upper extremity ROM and rotator cuff strength. LEVEL OF EVIDENCE: 3.

Rehabilitation of shoulder impingement syndrome and rotator cuff injuries: an evidence-based review.

Rehabilitation of the patient with glenohumeral impingement requires a complete understanding of the structures involved and the underlying mechanism creating the impingement response. A detailed clinical examination and comprehensive treatment programme including specific interventions to address pain, scapular dysfunction and rotator cuff weakness are recommended. The inclusion of objective testing to quantify range of motion and both muscular strength and balance in addition to the manual orthopaedic clinical tests allows clinicians to design evidence-based rehabilitation programmes as well as measure progression and patient improvement.

Clinical tests in shoulder examination: how to perform them.

BACKGROUND: This article describes the best clinical tests of shoulder function and injury as identified in a recent systematic review published in the British Journal of Sports Medicine. DISCUSSION: A description of the different tests is given, with photographs of the exact test procedure.

Step by Step Guide to Understanding the Kinetic Chain Concept in the Overhead Athlete.

PURPOSE OF REVIEW: The purpose of this review will be to provide both a historical and recent review of the role of the kinetic chain for the overhead athlete. The kinetic chain concept will then be applied to clinical exercise modifications and integrations for prevention and treatment of shoulder injury. RECENT FINDINGS: The primary conclusion reached through this review is the important role the lower extremity, trunk, and scapular region play in the development of optimal terminal segment acceleration in the overhead throwing and serving motion. Failure of any links in the kinetic chain has implications for shoulder and elbow injury in the overhead athlete. Modifications of traditional shoulder exercises emphasizing activation of the scapular stabilizers and core musculature alongside concomitant rotator cuff activation are recommended and supported in EMG research. Future research is needed to further identify risk factors and rehabilitation and prevention strategies and key clinical tests for the overhead athlete. The goal is to elucidate the important role the kinetic chain plays in both performance enhancement and injury prevention for the overhead athlete. Understanding the key role all segments of the kinetic chain play in the complex biomechanical segmental rotations required for high-level throwing and serving will assist clinicians who work with overhead athletes.

ELECTROMYOGRAPHIC ANALYSIS OF THE SCAPULAR DYSKINESIS TEST IN A BASEBALL PITCHER WITH A SLAP LESION: A CASE REPORT.

BACKGROUND AND PURPOSE: The return to play percentage of baseball pitchers who have undergone isolated superior labrum anterior-posterior (SLAP) repair has been reported to be less than 60%. Scapular dyskinesis (SD), characterized by scapular prominence during dynamic scapulohumeral movements, may be used to assist in diagnosing a baseball pitcher with shoulder pathology including a SLAP lesion. The purpose of this case report was to describe the use of the SD test to assess the scapular muscles and report EMG findings in a college baseball pitcher diagnosed with a Type 2 posterior SLAP lesion. CASE DESCRIPTION: The subject was a NCAA-D1 senior collegiate baseball right hand 3/4 slot pitcher (21 years old) with a primary complaint of pain in the anterior portion of the shoulder during the entire fall practice season, which was attributed to labral surgery performed when he was a senior in high school. No positive clinical testing of the patient was found including: the sulcus sign, tests of gross instability, and the load & shift test. A Type II posterior SLAP lesion was identified via magnetic resonance imaging. The subject presented with glenohuemral internal rotation deficit (GIRD). The SD test identified moderate to severe prominence of scapular medial boarder in shoulder flexion/extension (FLX/EXT). Furthermore, surface EMG analyses indicated that the lower trapezius (LT) muscle was abruptly inhibited on the dominant side during the descending phase of FLX, compared with the non-dominant side. Additionally, a remarkably higher ratio of upper trapezius to LT muscle EMG activity on the dominant side compared to that of the non-dominant side was identified during the descending phase from flexion. DISCUSSION: After identification of SD, an off season conservative treatment program allowed him to compete in his last college baseball season, appearing 22 times out of the bullpen in which he was credited four wins with a 3.70 earned run average (ERA) in 41.1 innings in 57 games. The SD test may play a critical role in identifying rehabilitation potential and guide the focus of the rehabilitation program to improve scapulothoracic stability and mobility for unilateral repetitive overhead athletes. Particularly the descending phase during sagittal plane motion (FLX/EXT) may effectively accentuate the scapular prominence during movement, portentially due to LT muscle activity inhibition. LEVEL OF EVIDENCE: 5 Case Report.