Shoulder pain in the overhead throwing athlete

Evaluation of the PhySens as a Wrist-Worn Wearable in Pitch Detection and Biomechanical Workload Estimation

BACKGROUND

The volume and frequency of throwing activity are among the most significant risk factors for developing overuse injuries in youth athletes. Despite introducing systematic guidelines for 'pitch counts,' throwing injuries continue to rise. Using technology to create enhanced measures of workload exposure in this unique population of athletes may help generate more effective and personalized injury prevention strategies.

HYPOTHESIS

The wrist-worn sensor system (PhySens) will: 1) accurately detect and differentiate throwing activity from other baseball movements, and 2) accurately predict ball velocity, arm slot angle, and elbow valgus torque.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 5.

METHODS

Youth pitchers (n = 10) performed a standardized protocol of pitching, field-throwing, and batting. Pitching velocity and biomechanical data were simultaneously captured by the PhySens and traditional 3-dimensional motion capture. The accuracy of the pitching detection algorithm (throw vs batting) was analyzed by comparing truth data with throwing events cataloged by the device. Ball velocity, elbow valgus torque, and arm slot angle predictions were assessed with Pearson correlation coefficients and Bland-Altman plots.

RESULTS

A total of 230 events (pitches and bat swings) were analyzed. Pitch detection was excellent, with a sensitivity of 99.4% and specificity 97.9%. Pearson correlations were significant and excellent across all predicted variables, with ball velocity r = 0.96, elbow valgus torque r = 0.95, and arm slot angle r = 0.87. The system demonstrated excellent estimations of ball velocity, elbow valgus torque, and arm slot angle.

CONCLUSION

This novel single-sensor wrist worn device was highly accurate in detecting pitching events, predicting ball velocity, and estimating arm slot angle and elbow valgus torque.

CLINICAL RELEVANCE

Throwing volume is highly associated with overuse injuries in youth baseball players. Sensor-based measures of workload monitoring can address inherent limitations related to human error and underestimation of true throwing exposure.

A narrative review of nerve compression syndromes in overhead throwing athletes

PURPOSE OF REVIEW

The purpose of this narrative review is to highlight upper extremity nerve compression syndromes and peripheral neuropathies reported in throwing and overhead athletes.

RECENT FINDINGS

The overhead-throwing athlete may experience unique patterns of injuries and pathology related to the biomechanics and demands of the throwing motion, a demanding manoeuvre that places a significant amount of stress across the upper limb. Nerve injuries that may appear in high-level throwers include suprascapular and long thoracic neuropathy, quadrilateral space syndrome, and thoracic outlet syndrome. Nerve compression syndromes around the shoulder may appear with pain, paresthesia, and upper limb weakness. Overlapping features may be common among these compression neuropathies or mimic other common shoulder pathologies. Prompt differential diagnosis and successful treatment should be based on knowledge of key anatomical features, pathophysiology, clinical examination, and appropriate paraclinical studies.

Current Concepts on the Management of Shoulder Instability in Throwing Athletes

PURPOSE OF REVIEW

The management of shoulder instability in throwing athletes remains a challenge given the delicate balance between physiologic shoulder laxity facilitating performance and the inherent need for shoulder stability. This review will discuss the evaluation and management of a throwing athlete with suspected instability with a focus on recent findings and developments.

RECENT FINDINGS

The vast majority of throwing athletes with shoulder instability experience subtle microinstability as a result of repetitive microtrauma rather than episodes of gross instability. These athletes may present with arm pain, dead arms or reduced throwing velocity. Recent literature reinforces the fact that there is no "silver bullet" for the management of these athletes and an individualized, tailored approach to treatment is required. While initial nonoperative management remains the hallmark for treatment, the results of rehabilitation protocols are mixed, and some patients will ultimately undergo surgical stabilization. In these cases, it is imperative that the surgeon be judicious with the extent of surgical stabilization as overtightening of the glenohumeral joint is possible, which can adversely affect athlete performance. Managing shoulder instability in throwing athletes requires a thorough understanding of its physiologic and biomechanical underpinnings. Inconsistent results seen with surgical stabilization has led to a focus on nonoperative management for these athletes with surgery reserved for cases that fail to improve non-surgically. Overall, more high quality studies into the management of this challenging condition are warranted.

Evolution of the throwing shoulder: why apes don't throw well and how that applies to throwing athletes

BACKGROUND

Humans have unique characteristics making us the only primate that can throw well while most other primates throw predominately underhand with poor speed and accuracy. The purpose of this study is to illuminate the uniquely human characteristics that allow us to throw so well. When treating an injury such as a labral tear or capsule tear, this study hopes the reader can gain a better understanding of the issues that lead to the tear and those that may determine the success of treatment besides the actual repair.

METHODS

In addition to a review of scientific and medical literature, information was obtained from interviews and experience with primate veterinarians, anthropologists, archeologists, and professional baseball players. These sources were used to study the connection between evolutionary throwing activities and current sports medicine issues.

RESULTS

Arm acceleration requires a functional kinetic chain, rapid motor sequences, and the ability to absorb elastic energy in the shoulder. Successful treatment of the throwing shoulder requires awareness of the shoulder's position in the kinetic chain and correction of defects in the ability to execute the kinetic chain. Some problems in the shoulder could reflect regression to a more primitive anatomy or dyskinesis. Return of performance requires regaining the elasticity in the tissues of the shoulder to temporarily store kinetic energy. For example, tissue remodeling after rotator cuff repair continues for months to years; however, the newly formed tissue lacks the same elasticity of the native tendon. This suggests why throwing performance typically does not return for 7 or more months after repair even though there may be structural integrity at 3-4 months.

CONCLUSION

The shoulder has developed uniquely in modern man for the act of throwing. The anatomic deficiencies in primates for throwing provide an illustration of the more subtle changes that a throwing athlete might have that are detrimental to throwing. Nonhuman primates have been unable to demonstrate the kinetic chain sequence for throwing secondary to the lack of neurologic pathways required. Humans are more sophisticated and precise in their movements but lack robusticity in their bone and muscle architecture, seen especially in the human rotator cuff. Successful treatment of a throwing injury requires familiarity with the conditions that cause the injury or affect the rehabilitation process. The return of performance following injury or surgery requires regaining the elasticity in the tissues of the shoulder to temporarily store kinetic energy from the kinetic chain.

Upper Body Injuries in Golfers

PURPOSE OF REVIEW

Golf is a sport that can be played by an athlete of any age, which enhances its popularity. Each golfer's swing is unique, and there is no "right" way to swing the golf club; however, the professional golfer often has more of a consistent swing as opposed to an amateur golfer. A collaborative, team approach involving the golfer with a swing coach, physical therapist, and physician often can be informative on how to prevent golf injury, but also how to treat golf injury if it occurs.

RECENT FINDINGS

As a rotational sport, the golfer needs to be trained and treated with respect for how the body works as a linkage system or kinetic chain. A warm-up is recommended for every golfer before practicing or playing, and this warm-up should account for every segment of the linkage system. Though it has been thought of as a relatively safe sport, injuries can be seen with golfers of any age or skill level, and upper body injuries involving the cervical and thoracic spine, shoulder, elbow, and wrist are common. A narrative review is provided here of the epidemiology of golf injury and common injuries involving each of these upper body regions. In addition, treatment and injury prevention recommendations are discussed.

The Thrower's Shoulder

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The thrower's shoulder has been a subject of great interest for many decades. Different theories have been proposed to clarify the pathophysiology, clinical presentation, and treatment options for this condition. In this review article, we summarize the relevant anatomy and pathophysiology and how these translate into signs, symptoms, and imaging findings. Also, a historical review of the treatment methodologies in the setting of an evolving concept is presented.

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The initial event in the cascade is thickening and contracture of the posteroinferior capsule resulting from repetitive tensile forces during the deceleration phase of throwing. This is known as "the essential lesion" and is clinically perceived as glenohumeral internal rotation deficit (GIRD), and a Bennett lesion may be found on radiographs.

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Change in the glenohumeral contact point leads to a series of adaptations that are beneficial for the mechanics of throwing, specifically in achieving the so-called "slot," which will maximize throwing performance.

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The complexity of the throwing shoulder is the result of an interplay of the different elements described in the cascade, as well as other factors such as pectoralis minor tightness and scapular dyskinesis. However, it is still unclear which event is the tipping point that breaks the balance between these adaptations and triggers the shift from an asymptomatic shoulder to a painful disabled joint that can jeopardize the career of a throwing athlete. Consequences are rotator cuff impingement and tear, labral injury, and scapular dyskinesis, which are seen both clinically and radiographically.

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A thorough understanding of the pathologic cascade is paramount for professionals who care for throwing athletes. The successful treatment of this condition depends on correct identification of the point in the cascade that is disturbed. The typical injuries described in the throwing shoulder rarely occur in isolation; thus, an overlap of symptoms and clinical findings is common.

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The rationale for treatment is based on the pathophysiologic biomechanics and should involve stretching, scapular stabilization, and core and lower-body strengthening, as well as correction of throwing mechanics, integrating the entire kinetic chain. When nonoperative treatment is unsuccessful, surgical options should be tailored for the specific changes within the pathologic cascade that are causing a dysfunctional throwing shoulder.

A Review of Upper Extremity Peripheral Nerve Injuries in Throwing Athletes

Peripheral nerve injuries in the upper extremities may be common in throwing athletes as the throwing motion places extreme stress on the dominant arm. The combination of extreme stress along with repetitive microtrauma from throwing uniquely places the throwing athlete at elevated risk of upper extremity peripheral nerve injury. However, because symptoms can be non-specific and frequent co-exist with pathology in the upper extremity, the diagnosis of peripheral nerve injury is often delayed. Diagnosis of peripheral nerve injuries may require a combination of history and physical exam, diagnostic imaging, electrodiagnostic testing, and diagnostic ultrasound guided injections. The primary management should include physical therapy focusing on throwing mechanics and kinetic chain evaluation. However, some athletes require surgical intervention if symptoms do not improve with conservative management. The purpose of this focused narrative review is to highlight upper extremity peripheral neuropathies reported in throwing athletes and to provide an overview of the appropriate clinical diagnosis and management of the throwing athlete with a peripheral nerve injury. This article is protected by copyright. All rights reserved.

Management Options for Shoulder Impingement Syndrome in Athletes: Insights and Future Directions

Athletes participating in overhead sports are at particularly high risk of shoulder impingement syndrome. Subcoracoid impingement is defined as impingement of the anterior soft tissues of the shoulder between the coracoid process and the lesser tuberosity. Subacromial impingement syndrome (SIS) occurs due to extrinsic compression of the rotator cuff between the humeral head and coracoacromial structures or intrinsic degeneration of the supraspinatus tendon and subsequent superior migration of the humerus. Internal impingement is a major cause of shoulder pain in overhead athletes, and it occurs due to repetitive impingement of the articular surface of the rotator cuff with the glenoid during maximum abduction and external rotation of the arm. When examining athletes with suspected impingement of the shoulder, it is important to discuss the sport-specific motion that regenerates the symptoms and perform a combination of physical examination tests to improve the diagnostic accuracy. Radiographic evaluation is recommended, and the extent of soft tissue abnormalities can be assessed on ultrasound or magnetic resonance imaging of the shoulder. Management of shoulder impingement syndrome can be conservative or operative, based on the severity and chronicity of symptoms and the associated structural abnormalities. This review provides an update on the management of SIS, subcoracoid impingement, and internal impingement in the athletic population.

Chronic Adaptations of the Posterior Rotator Cuff in Professional Pitchers

BACKGROUND

Because of the large forces and high frequency of throwing, the upper extremity experiences repetitive stresses that lead to acute and chronic adaptations. While the importance of pennation angle and muscle thickness as predictors of muscle force production has been shown in other populations and other joints, there has been little research done that examines these variables in the shoulders of baseball players.

PURPOSE

(1) To examine the chronic effect pitching has on the rotator cuff muscle architecture (pennation angle and muscle thickness) in healthy professional baseball pitchers, and (2) to examine the correlation between muscle architecture and clinical measures of strength and range of motion (ROM).

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Twenty-eight healthy professional pitchers were recruited during the 2019 spring training. Internal rotation (IR) and external rotation (ER) strength were measured with a handheld dynamometer and IR and ER ROM were measured with an inclinometer. A diagnostic ultrasound machine was utilized to capture images of humeral retroversion, as well as the pennation angle and muscle thickness of the infraspinatus and teres minor muscles. ImageJ software was used to quantify the pennation angle and muscle thickness.

RESULTS

There were no significant differences between the dominant and nondominant arms for ER or IR strength. Also, no pennation angle and muscle thickness differences were found between the dominant and nondominant arms. A weak positive relationship between infraspinatus muscle thickness (superficial and total) and ER strength (P = .016, R = 0.287 and P = .009, R = 0.316) and a moderate negative relationship between soft tissue glenohumeral internal rotation deficit (GIRD) and the bilateral difference of the teres minor deep pennation angle (R = -0.477, P = .008) were observed. No other significant relationships were noted.

CONCLUSION

Our results are contrary to current literature as we expected to see a stronger dominant arm, with a larger pennation angle and greater muscle thickness. Interestingly, we found that ER strength was positively related to only the thickness of the infraspinatus muscle, and that soft tissue GIRD was positively related to only the side-to-side adaptation of the pennation angle within the deep portion of the teres minor. This suggests that when posterior shoulder tightness occurs, specifically the architecture of the teres minor muscle is involved. However, the organization to which these players belonged has a very extensive training protocol throughout the year that emphasizes bilateral training during a large majority of the exercises. Therefore, the results may not be generalizable to all professional players.

CORRELATION BETWEEN THE KERLAN-JOBE ORTHOPEDIC CLINIC SCREEN AND SUBACROMIAL IMPINGEMENT TEST-ITEM CLUSTER IN COLLEGIATE BASEBALL PITCHERS: A PILOT STUDY

Background

Shoulder injuries in baseball related to throwing account for 60% of all baseball injuries and 75% of those throwing injuries occur in pitchers. Impingement is the beginning of a continuum of rotator cuff pathology that can result in pain and disability in pitchers. Identification of self-reported measures and clinical tests that can indicate early pathology of shoulder impingement is needed for overhead athletes. Early identification of shoulder impingement is important to the long-term health and function of these athletes.

Hypothesis/Purpose

The purpose of this study was to determine if a correlation exists between self-reported pain and disability using the Kerlan-Jobe Orthopedic Clinic (KJOC) score and the Park Test-Item Cluster (TIC) for subacromial impingement in college baseball pitchers. The research hypotheses are that there will be a correlation 1) between the KJOC score and the TIC by Park and 2) between the KJOC and the Hawkins-Kennedy impingement, the painful arc, and the infraspinatus muscle strength tests individually.

Design

Cross-sectional pilot study.

Methods

Twenty-one collegiate baseball pitchers completed the KJOC and then were tested using the Park test-item cluster.

Data Analysis

Kruskal-Wallis was used to test the relationship of individual demographics with KJOC scores. Spearman rho correlation was used to determine if the number of positive clinical tests in the Park TIC or with the individual tests within the TIC correlated with scores on the KJOC.

Results

No significant relationships between KJOC scores and demographics were found. A significant moderate-to-good relationship was found between the painful arc test and the KJOC (r = -.601, p = 0.00) and a significant fair correlation was found between the number of positive tests within the Park TIC and KJOC (r = -.426, p = 0.05). No significant relationships were found between the Hawkins-Kennedy and KJOC (r = -.348, p = 0.12) or between the infraspinatus strength test and KJOC (r = -.040, p = 0.86).

Conclusion

The correlations between the painful arc test and the number of positive impingement tests with the composite score on the KJOC suggests a relationship between these two outcome measures, shoulder irritability, and decreased function in collegiate baseball pitchers. Of the three tests included in the Park TIC, the painful arc test was the only one with an independent significant correlation to the KJOC. The combination of impairment-specific cluster testing and an activity-focused self-assessment tool could be utilized to identify potential pathology and alert the medical professional that assessment and intervention are necessary.

Level of Evidence

Level 2 (Diagnosis).

Tight shoulders: A clinical, kinematic and strength comparison of symptomatic and asymptomatic male overhead athletes before and after stretching

A tightness of the posterior structures of the throwing shoulder has been hypothesised to be associated with injuries and pain because of alterations of the scapular kinematics and muscular imbalances. The aims of this study were to identify the clinical and biomechanical profile of symptomatic and asymptomatic overhead athletes with a tight shoulder and to evaluate the efficiency of a self-applied stretching program. Twenty male overhead athletes were recruited. Half of them reported a painful shoulder at the beginning of the study. For four weeks, the volunteers performed daily stretching exercises. Before and after the stretching program, gleno-humeral mobility, scapular kinematics, rotator muscles strength and pain were evaluated. Before stretching, the main difference between the groups was more impingement syndrome and rotator cuff tendon lesion positive tests in the symptomatic group (p < 0.027, effect size = 0.51). After the program, pain reported by the symptomatic volunteers was reduced by approximately 40% and the gleno-humeral internal rotation bilateral difference was significantly reduced by 77.6% (p < 0.009, effect size = 0.84). In the symptomatic group, the scapula at rest was significantly more posteriorly tilted (p = 0.027, effect size = 0.69) after the stretching; a position that has been shown to limit the risk of impingement. The absence of significant differences of the profiles of the symptomatic and asymptomatic overhead athletes before stretching may indicate that the initiation of early prevention programs, including self-applied stretching, should not rely solely on biomechanical and clinical parameters and might be recommended to all players with a tight shoulder.

Effect of neuromuscular training on functional throwing performance and speed in asymptomatic cricket players

OBJECTIVE

To determine the effect of neuromuscular training on functional throwing performance and speed among asymptomatic cricket players.

DESIGN

Single-subject A-B-A design.

METHOD

Forty-three male asymptomatic sub-elite cricket players were recruited from Karnataka Institute of Cricket, Bangalore, India, with a mean age of 20.4 ± 2.03 years. Throwing accuracy and throwing speed were measured using Functional Throwing Performance Index (FTPI) and radar gun respectively, at zero, 12, 24 and 30 weeks in accordance with the A-B-A single-subject design. The neuromuscular training of the throwing arm was performed for 12 weeks, two days a week of supervised training including rhythmic stabilization drills were performed. A non-supervised training session including shoulder strengthening programme was conducted three days a week.

RESULT

Participants demonstrated significant improvement in throwing accuracy (p < 0.001) and speed (p < 0.001) after 12 weeks of neuromuscular training. Six weeks post-withdrawal of the neuromuscular training on throwing accuracy was not significant (p = 0.117), However, speed was sustained (p = 0.013).

CONCLUSION

Neuromuscular training showed an improved efficiency in throwing performance following 12 weeks of training in sub-elite cricket players. The sustained effect was not observed following 6 weeks of withdrawal of training.

Needle placement approach to subacromial injection in patients with subacromial impingement syndrome: A systematic review

BACKGROUND

Subacromial impingement syndrome (SAIS) is the most common cause of shoulder pain and is costly, in terms of disability and health service provision. Research evidence suggests that, generally, the anterior, lateral and posterior approaches are used by clinicians for subacromial injection. However, it is uncertain which of these approaches is more effective than the other in the management of SAIS.

OBJECTIVES

The aim of the present study was to determine the effectiveness of the anterior, lateral approach to subacromial injection compared with the posterior approach for the treatment of SAIS.

METHODS

A comprehensive search was undertaken of CINAHL, MEDLINE, Cochrane, PEDro and the E-Journals databases using full texts, from 1980 to April 2014 and updated in December 2016 via the Chartered Society of Physiotherapy (EBSCOhost). Studies of SAIS patients receiving cortisone injections which investigated needle placement through the lateral, posterior or anterior routes were included. Study selection, data extraction and appraisal of the study were undertaken by the researcher and his supervisor. Quality criteria were selected from PEDro, to form a checklist of 10 items.

RESULTS

A total of 4265 citations were retrieved and screened for eligibility; 39 articles were assessed as full text and 8 met the inclusion criteria. They include four randomized controlled trials and four controlled trials. Due to the varying methodological quality, and clinical and statistical heterogeneity of these studies, they were analysed qualitatively, as a meta-analysis was not possible.

CONCLUSIONS

The evidence establishing the superiority of any one method of subacromial injection approach over the other is unclear in clinical practice. This calls for further research into this area.

Image guided injection therapies in athletes-Do they work and what should we be using?

In the modern management of the injured elite athlete, the goals of guided injection therapies have extended beyond simple reduction of pain to enhancement of tissue healing and accelerated return to competition, faster than natural healing can allow. This article will review the injection therapies which are frequently used in elite sports injury management and describe other less commonly used injection therapies that are available to the treating clinician and athlete. The evidence base, where available, for each treatment option will be summarised.

Shoulder Injuries in the Overhead-Throwing Athlete: Epidemiology, Mechanisms of Injury, and Imaging Findings

The unparalleled velocity achieved by overhead throwers subjects the shoulder to extreme forces, resulting in both adaptive changes and pathologic findings that can be detected at imaging. A key biomechanical principle of throwing is achieving maximum external rotation, which initially leads to adaptive changes that may result in a pathologic cascade of injuries. In addition to the well-established concepts of glenohumeral internal rotation deficit and internal impingement, osseous and soft-tissue injuries of the shoulder unique to overhead athletes are illustrated. The epidemiology and biomechanics of throwing injuries are reviewed, and examples from the authors' institutional experience with competitive, collegiate, and professional baseball players are provided to demonstrate the constellation of unique imaging findings seen in overhead throwing athletes. Given the widespread popularity of baseball, and other sports relying on overhead throwing motions at all playing levels from recreational to professional, it is important for radiologists in various practice settings to be familiar with the special mechanisms, locations, and types of shoulder injuries seen in the overhead throwing population. ^© RSNA, 2018.

Quadrilateral Space Syndrome: Diagnosis and Clinical Management

Quadrilateral space syndrome (QSS) is a rare disorder characterized by axillary nerve and posterior humeral circumflex artery (PHCA) compression within the quadrilateral space. Impingement is most frequently due to trauma, fibrous bands, or hypertrophy of one of the muscular borders. Diagnosis can be complicated by the presence of concurrent traumatic injuries, particularly in athletes. Since many other conditions can mimic QSS, it is often a diagnosis of exclusion. Conservative treatment is often first trialed, including physical exercise modification, physical therapy, and therapeutic massage. In patients unrelieved by conservative measures, surgical decompression of the quadrilateral space may be indicated.

Shoulder Injuries in National Collegiate Athletic Association Quarterbacks: 10-Year Epidemiology of Incidence, Risk Factors, and Trends

Background:

Up to 50% of National Collegiate Athletic Association (NCAA) football players have a history of shoulder injuries. The quarterback position has been shown to have a high prevalence of these injuries because of its unique exposures. There is little information regarding the shoulder injury type and mechanism in NCAA quarterbacks.

Purpose:

To understand the 10-year epidemiology of specific shoulder injury rates in NCAA quarterbacks.

Study Design:

Descriptive epidemiology study.

Methods:

Shoulder injury data for collegiate football quarterbacks from the 2004 through 2014 academic years were analyzed using the NCAA Injury Surveillance Program (ISP) data set.

Results:

Over the 10-year study period, a total of 133 shoulder injuries to collegiate quarterbacks were reported, with 157,288 quarterback exposures. There was approximately 1 shoulder injury per 1221 exposures. The most common injuries noted were acromioclavicular sprains (45.1%, n = 60), followed by shoulder contusions (9.0%, n = 12), clavicular fractures (7.5%, n = 10), and anterior instability (5.3%, n = 7). The majority of injuries were caused by contact with a player (60.2%, n = 80) or contact with a playing surface (28.6%, n = 38), and 88% (n = 117) were deemed nonsurgical in nature.

Conclusion:

NCAA ISP data analysis suggests that collegiate quarterbacks sustain acute contact injuries 89% of the time and that they typically occur while being tackled, resulting in a time loss of less than 2 weeks. These injuries are commonly treated nonsurgically.

Peripheral nerve injury in sport: an overview

Peripheral nerve injury in sport results from acute trauma or repetitive overuse. Repetitive overuse injuries must be assessed with the broad context of tissue overload, kinetic chain continuum, periodization, recovery, equipment, and sport-specific biomechanics. Simply diagnosing the anatomic location and extent of nerve injury is inadequate. Management must consider all contributors to nerve injury. This chapter provides an overview of emerging information for assessing and managing peripheral nerve injury in sport.

Pathologies of the shoulder and elbow affecting the overhead throwing athlete

The overhead-throwing athlete is susceptible to a variety of predictable disease entities affecting the shoulder and elbow. While the pathophysiology and nomenclature of these diseases are ubiquitous throughout the clinical literature, this information is sparse within the radiology domain. We provide a comprehensive review of these unique injuries with accompanying imaging features in an effort to enhance the role of the radiologist during the management of the overhead thrower. When appropriately recognized and described, the imaging features aid in establishing a diagnosis and ultimately the implementation of appropriate clinical management.

Shoulder Injuries in the Overhead Throwing Athlete

The overhead pitching motion is a coordinated sequence of movements that subjects the shoulder to extreme forces. The ultimate goal of this complex, dynamic activity is to generate high ball velocity and accuracy. In doing so, repetitive throwing can cause adaptive and pathologic changes in the thrower's shoulder. This article reviews the relevant shoulder anatomy, the kinetic chain, and throwing mechanics, as well as common shoulder injuries and surgical options for the treating orthopedic surgeon.

The Kinetic Chain Revisited: New Concepts on Throwing Mechanics and Injury

The overhead throwing motion is a complex activity that is achieved through activation of the kinetic chain. The kinetic chain refers to the linkage of multiple segments of the body that allows for transfer of forces and motion. The lower extremities and core provide a base of support, generating energy that is transferred eventually through the throwing arm and hand, resulting in release of the ball. The kinetic chain requires optimal anatomy, physiology, and mechanics and is involved in all 6 phases of overhead throwing: windup, stride, arm cocking, acceleration, deceleration, and follow-through. Breaks or deficits in the kinetic chain can lead to injury or decreased performance. Through an understanding of the mechanics and pathomechanics seen in each phase of throwing, the clinician can better evaluate and screen for potential kinetic chain deficits in the overhead throwing athlete. The purpose of this article is to review the biomechanics of the overhead throwing motion, the role of the kinetic chain in throwing, and the clinical evaluation and management of abnormal throwing mechanics and related injuries.

Surgical Release of the Pectoralis Minor Tendon for Scapular Dyskinesia and Shoulder Pain

BACKGROUND

Pectoralis minor (PM) tightness has been linked to pain and dysfunction of the shoulder joint secondary to anterior tilt and internal rotation of the scapula, thus causing secondary impingement of the subacromial space.

PURPOSE

To describe outcomes pertaining to nonoperative and operative treatment via surgical release of the PM tendon for pathologic PM tightness in an active population.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Over a 3-year period, a total of 46 patients were enrolled (mean age, 25.5 years; range, 18-33 years). Inclusion criteria consisted of symptomatic shoulder pain, limited range of overhead motion, inability to participate in overhead lifting activities, and examination findings consistent with scapular dysfunction secondary to a tight PM with tenderness to palpation of the PM tendon. All patients underwent a lengthy physical therapy and stretching program (mean, 11.4 months; range, 3-23 months), which was followed by serial examinations for resolution of symptoms and scapular tilt. Of the 46 patients, 6 (13%) were unable to adequately stretch the PM and underwent isolated mini-open PM release. Outcomes were assessed with scapula protraction measurements and pain scales as well as American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) scores.

RESULTS

Forty of the 46 patients (87%) resolved the tight PM and scapular-mediated symptoms with a dedicated therapy program (pre- and posttreatment mean outcome scores: 58 and 91 [ASES], 50 and 90 [SANE], 4.9 and 0.8 [VAS]; P < .01 for all), but 6 patients were considered nonresponders (mean score, 48 [ASES], 40 [SANE], 5.9 [VAS]) and elected to have surgical PM release, with improved scores in all domains (mean score, 89 [ASES], 90.4 [SANE], 0.9 [VAS]; P < .01) at final follow-up of 26 months (range, 25-30 months). Additionally, protraction of the scapula improved from 1.2 to 0.3 cm in a mean midline measurement from the chest wall preoperatively to postoperatively ( P < .01), similar to results in nonoperative responders. No surgical complications were reported, and all patients returned to full activities.

CONCLUSION

In most patients, PM tightness can be successfully treated with a nonoperative focused PM stretching program. However, in refractory and pathologically tight PM cases, this series demonstrates predictable return to function with notable improvement in shoulder symptoms after surgical release of the PM. Additional research is necessary to evaluate the long-term efficacy of isolated PM treatment.

The volleyball athlete's shoulder: biomechanical adaptations and injury associations

In volleyball, the dominant shoulder of the athlete undergoes biomechanical and morphological adaptations; however, definitive conclusions about their exact nature, aetiology, purpose and associations with shoulder injury have not been reached. We present a systematic review of the existing literature describing biomechanical adaptations in the dominant shoulders of volleyball players and factors that may predispose to shoulder pain/injury. A thorough literature search via Medline, EMBASE and SCOPUS was conducted for original studies of volleyball players and 15 eligible articles were identified. Assessment of study quality was performed using the STROBE statement. The reviewed literature supports the existence of a glenohumeral internal rotation deficit (GIRD) and a possible (and less pronounced) external rotation gain in the dominant vs. the non-dominant shoulder of volleyball athletes. Unlike other overhead sports, the GIRD in volleyball athletes appears to be anatomical as a response to the repetitive overhead movements and not to be associated with shoulder pain/injury. Additionally, the dominant shoulder exhibits muscular imbalance, which appears to be a significant risk factor for shoulder pain. Strengthening of the external rotators should be used alongside shoulder stretching and joint mobilisations, core strengthening and optimisation of spike technique as part of injury management and prevention programmes.

CHRONIC UCL INJURY: A MULTIMODAL APPROACH TO CORRECTING ALTERED MECHANICS AND IMPROVING HEALING IN A COLLEGE ATHLETE- A CASE REPORT

BACKGROUND

Ulnar collateral ligament (UCL) tears and associated Tommy Johns surgical intervention from excessive and poor quality pitching has increased immensely-with more college and professional pitchers undergoing the surgery in 2014 alone than in the 1990s as a whole.(1) Faulty mechanics developed at young ages are often well-engrained by the late adolescent years and the minimal healing ability of the largely avascular UCL often leads to delayed safe return to sport.(2).

PURPOSE

The purpose of this case study was to describe an innovative, multimodal approach to conservative management of a chronic UCL injury in a college-aged baseball pitcher. This innovative approach utilizes both contractile and non-contractile dry needling to enhance soft tissue healing combined with standard conservative treatment to decrease pain and improve sport performance as measured by the Disabilities of Arm, Shoulder and Hand (DASH), Numeric Pain Report Scale (NPRS), and return to sport.

STUDY DESIGN

Retrospective Case Report.

CASE DESCRIPTION

A collegiate athlete presented to an outpatient orthopedic physical therapy clinic for treatment of UCL sprain approximately six weeks post-injury and platelet-rich plasma injection. Diagnostic testing revealed chronic ligamentous microtrauma. Impairments at evaluation included proximal stabilizing strength deficits, myofascial trigger points throughout the dominant upper extremity, improper pitching form, and inability to pitch in game conditions due to severe pain. Interventions included addressing strength deficits throughout the body, dry needling, and sport-specific biomechanical training with pitching form analysis and correction.

OUTCOMES

Conventional DASH and Sport-Specific scale on the DASH and the numeric pain rating scale improved beyond both the minimally clinically important difference and minimal detectable change over the 12 week treatment(3,4) At 24-week follow up, conventional DASH scores decreased from 34.20% disability to 3.33% disability while sport-specific DASH scores decreased from 100% disability to 31.25% disability. Although initially unable to compete due to high pain levels, the subject is currently completing his pitching role full-time with 1/10 max pain.

DISCUSSION

The approach used in this case study provides an innovative approach to conservative UCL partial tear treatment. Dry needling of both contractile and non-contractile tissue in combination with retraining of faulty mechanics may encourage chronically injured ligamentous tissue healing and encourage safe return to sport.

LEVEL OF EVIDENCE

Level 4.

Posterior shoulder instability in the athletic population: Variations in assessment, clinical outcomes, and return to sport

Posterior instability of the shoulder is becoming an increasingly recognized shoulder injury in the athletic population. Diagnostic elements, such as etiology, directionality, and degree of instability are essential factors to assess in the unstable athletic shoulder. Concomitant injuries and associated pathologic lesions continue to be a significant challenge in the surgical management of posterior shoulder instability. Return to sport and previous level of play is ultimately the goal for every committed athlete and surgeon, thus subpopulations of athletes should be recognized as distinct entities requiring unique diagnostic, functional outcome measures, and surgical approaches.

Disc Golf, a Growing Sport: Description and Epidemiology of Injuries

BACKGROUND

Disc golf is a sport played much like traditional golf, but rather than using a ball and club, players throw flying discs with various throwing motions. It has been played by an estimated 8 to 12 million people in the United States. Like all sports, injuries sustained while playing disc golf are not uncommon. Although formalized in the 1970s, it has grown at a rapid pace; however, disc golf-related injuries have yet to be described in the medical literature.

PURPOSE

To describe the most common injuries incurred by disc golf players while comparing the different types of throwing styles.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

The data in this study were collected from 883 disc golf players who responded to an online survey collected over a 1-month period. Respondents answered 49 questions related to demographics, experience, style of play, and injury details. Using a chi-square analysis, common injuries sustained in players using backhand and forehand throwing styles were compared.

RESULTS

More than 81% of respondents stated that they had sustained an injury playing disc golf, including injuries to the elbow (n = 325), shoulder (n = 305), back (n = 218), and knee (n = 199). The injuries were most commonly described as a muscle strain (n = 241), sprain (n = 162), and tendinitis (n = 145). The type of throw primarily used by players varied, with 86.2% using backhand, 12.7% using forehand, and 1.1% using an overhead throw. Players using a forehand throw were more likely to sustain an elbow injury (P = .014). Many players (n = 115) stated they had undergone surgery due to a disc golf-related injury, with the most common surgeries including meniscal, shoulder, spine, and foot/ankle surgeries.

CONCLUSION

The majority of surveyed disc golfers sustained at least 1 injury while playing disc golf, with many requiring surgery. The types of injuries sustained by players varied by the types of throw primarily used. As the sport of disc golf continues to expand, health professionals should be aware of injuries sustained, with future studies focusing on injury prevention and education strategies.

The effect of glenohumeral internal rotation deficit on the isokinetic strength, pain, and quality of life in male high school baseball players

Objective

To investigate the effects of glenohumeral internal rotation deficit (GIRD) on the isokinetic strength, body pain, and the quality of life in male high school baseball players of Korea.

Methods

Fifty-six male high school baseball players were divided into either group A (GIRD≥20°, n=12) or group B (GIRD<20°, n=44). The range of motion in the shoulder and the isokinetic strength were measured. Questionnaires were administered regarding the body pain location by using the visual analogue scale, and the quality of life was measured by using the SF-36 Form.

Results

All subjects had increased external rotation range of motion and decreased internal rotation in the throwing shoulder. The incidence of GIRD (≥20°) was 21.43% in the present study. In the isokinetic strength test, a significantly weaker muscular state at an angular velocity of 180°/s was observed in group A, compared to group B. For the comparison of the pain, the frequency of shoulder pain was higher (33.93%) than other body pain, among the study subjects.

Conclusion

GIRD is one of the main risk factors of glenohumeral joint damage, and it is correlated with reduced isokinetic strength and quality of life. High school baseball players will need appropriate shoulder rehabilitation programs for the improvement in their quality of life and performance.

Stress fracture of the scapula in a professional baseball pitcher: case report and review of the literature

We report a case of a 26-year-old, right-handed professional baseball pitcher who presented with gradually worsening right shoulder pain. Initial magnetic resonance imaging and computed tomography demonstrated a stress fracture involving the posterior aspect of the scapula at the junction between the scapular neck and body. After a period of rest, follow-up magnetic resonance imaging and computed tomography performed 3 1/2 weeks later demonstrated ongoing healing of the stress fracture.

Diagnosis and management of superior labral anterior posterior tears in throwing athletes

Injury to the superior glenoid labrum is increasingly recognized as a significant source of shoulder pain and dysfunction in the throwing athlete. Several theories have been proposed to explain the pathogenesis of superior labral anterior posterior (SLAP) tears. The clinical examination of the superior labrum-biceps tendon complex remains challenging because of a high association of other shoulder injuries in overhead athletes. Many physical examination findings have high sensitivity and low specificity. Advances in soft tissue imaging such as magnetic resonance arthrography allow for improved detection of labrum and biceps tendon lesions, although correlation with history and physical examination is critical to identify symptomatic lesions. Proper treatment of throwers with SLAP tears requires a thorough understanding of the altered biomechanics and the indications for nonoperative management and arthroscopic treatment of these lesions.

Paget Schroetter Syndrome: A case study of the chiropractor's role in recognizing and comanaging an important condition

OBJECTIVE

To emphasize the importance for health care professionals to be knowledgeable of a relatively rare form of thoracic outlet syndrome, known as Paget Schroetter syndrome. The etiology, key signs and symptoms, and the importance of immediate referral are highlighted and an introduction to manual therapists' role within a multidisciplinary team is provided.

CLINICAL FEATURES

Healthy athletes aged 15-30 are most commonly affected with 60-80% of patients reporting a history of repetitive or vigorous overhead activity prior to symptom onset.

INTERVENTION AND OUTCOME

Manual therapists have a role in recognizing, referring, and providing symptomatic relief with soft tissue therapy, correcting abnormal biomechanics, manipulations, mobilizations, and a rehabilitative program, as seen in this case report.

CONCLUSION

Early recognition and referral of Paget Schroetter syndrome are essential for optimal recovery. Manual therapists may prove to have a role in decreasing the need for surgical decompression and accelerating resumption of regular activities.

Scapular contribution for the end-range of shoulder axial rotation in overhead athletes

The aim of this study was to analyze the relative contribution of the scapular motion on the extreme range-of-motion of shoulder external and internal rotation, in overhead athletes. An electromagnetic tracking device (Flock of Birds) was used to record humeral and scapular kinematics. The dominant arm of 26 male subjects (13 athletes and 13 non-athletes) was studied while subjects actively reached end-range of internal and external rotation. Humeral and scapular angles were calculated and compared across groups by means of a t-test for independent samples. A bivariate correlation approach was used to describe the relationship between humeral angles and scapular variables. The range-of-motion of the thoracohumeral angles, during shoulder external rotation was significantly less (p < 0.05) on the athletes group, athletes also positioned their dominant scapula more retracted and posteriorly tilted. A positive correlation was found between glenohumeral angles and scapular tilt (r = 0.6777; p < 0.05). Concerning internal rotation; athletes showed significantly greater (highest) thoracohumeral angles (p < 0.05). Scapula assumed a position more in retraction and anterior tilt. Based on these findings, it is suggested that differences found in athletes seem to reveal an eventual shoulder adaptation to the throwing mechanics.

Effort thrombosis presenting as pulmonary embolism in a professional baseball pitcher

Context:

Effort thrombosis, or Paget-Schroetter’s syndrome, is a rare subset of thoracic outlet syndrome in which deep venous thrombosis of the upper extremity occurs as the result of repetitive overhead motion. It is occasionally associated with pulmonary embolism. This case of effort thrombosis and pulmonary embolus was in a 25-year-old major league professional baseball pitcher, in which the only presenting complaints involved dizziness and shortness of breath without complaints involving the upper extremity—usually, a hallmark of most cases of this condition. The patient successfully returned to play for 5 subsequent seasons at the major league level after multimodal treatment that included surgery for thoracic outlet syndrome.

Objective:

Though rare, effort thrombosis should be included in the differential diagnosis of throwing athletes with traditional extremity-focused symptoms and in cases involving pulmonary or thoracic complaints. Rapid diagnosis is a critical component of successful treatment.

Baseball and softball

Baseball and softball are among the most popular and safest sports in which children and adolescents participate. Nevertheless, traumatic and overuse injuries occur regularly, including occasional catastrophic injury and even death. Safety of the athlete is a constant focus of attention among those responsible for modifying rules. Understanding the stresses placed on the arm, especially while pitching, led to the institution of rules controlling the quantity of pitches thrown in youth baseball and established rest periods between pitching assignments. Similarly, field maintenance and awareness of environmental conditions as well as equipment maintenance and creative prevention strategies are critically important in minimizing the risk of injury. This statement serves as a basis for encouraging safe participation in baseball and softball. This statement has been endorsed by the Canadian Paediatric Society.