Throwing Shoulder Research Articles

Current Concepts

Magnetic resonance imaging (MRI) findings are common in patients and athletes with shoulder pain. Historically these anatomic derangements have been thought to be the source of the patient's symptoms, and approaches have been focused on restoring the anatomy. This manuscript will address three objectives: (1) suggest that the approach to rotator cuff disease should be based on the patient's history and physical examination, and not necessarily on the anatomic disorders apparent on imaging; (2) review the data that supports the contention that rotator cuff disease is not the source of pain in the symptomatic shoulder, and (3) describe the concept of adaptive pathology. The findings on the MRI in the thrower's painful shoulder may be adaptive, and these alterations may be required to allow performance at high levels in sport.

投球障害肩に対する肩峰下滑液包内および肩関節内局所麻酔剤注入テスト(投球テスト)の診断的価値

投球障害肩に対する肩峰下滑液包内および肩関節内局所麻酔剤注入テスト(投球テスト)の診断的価値

Physical Examination of the Overhead Athlete’s Shoulder

Overhead athletes seek the services of an orthopedic surgeon because of pain and/or dysfunction. It is important to address the cause of the symptoms more so than the source of the patient's pain, so that treatment will eliminate the problem rather than merely ameliorate symptoms temporarily. In order to accomplish a thorough assessment of shoulder function, the examiner must expand his/her view from isolated assessment of the glenohumeral joint range of motion, stability, assessment of rotator cuff strength, palpation and provocative maneuvers, and add assessment of the shoulder in the context of the kinetic chain. The examination of the thrower's shoulder, coupled with a thorough history, will usually provide a solid functional diagnosis and provide a good idea as to the presence of structural damage. As a result, the value of rehabilitation and the benefit of surgical intervention are made more predictable.

Rehabilitation After Surgical Management of the Thrower's Shoulder

The overhead throwing motion is a complex and coordinated movement pattern involving the lower extremities, the trunk, and the upper extremity. Because of these tremendous demands on the shoulder, various shoulder injuries may occur. Two of the more common injuries to throwers are shoulder instability and superior labrum anterior-posterior lesions. Although nonoperative treatment is frequently successful in treating these conditions, surgical management may be necessary for the athlete to return to their sport. The purpose of this article is to review the first 3 phases of rehabilitation after arthroscopic capsular stabilization and superior labrum anterior-posterior debridement or repair. The fourth phase, return to throwing, will be covered in the final section.

Repair of Partial Tears of the Rotator Cuff

Partial-thickness rotator cuff tears present partial disruption of tendon fibers with no communication between the subacromial bursa and the glenohumeral joint. The clinical presentation is surprisingly variable, ranging from mild discomfort to decreased throwing speed, chronic pain, and shoulder inability. The first approach to partial-thickness rotator cuff tears is usually conservative, but the hypovascularity of the critical zone and mechanical factors often result in poor spontaneous tendon healing. Surgical options include arthroscopic cuff "debridement" or "repair," performed arthroscopically or by open surgery, and subacromial decompression or debridement if necessary. No agreement has been reached on the best surgical management. However, repair is usually indicated if bursal-sided and articular tears involve more than 50% of tendon thickness; debridement is generally undertaken if <50% of the rotator cuff is torn. There is a need for randomized clinical trails formulating and testing guidelines of management and for further studies on imaging or intraoperative measures and methods to assess the thickness of the rotator cuff to inform management.

A Profile of Glenohumeral Internal and External Rotation Motion in the Uninjured High School Baseball Pitcher, Part I: Motion

The magnitude of motion that is normal for the throwing shoulder in uninjured baseball pitchers has not been established. Chronologic factors contributing to adaptations in motion present in the thrower's shoulder also have not been established. To develop a normative profile of glenohumeral rotation motion in uninjured high school baseball pitchers and to evaluate the effect of chronologic characteristics on the development of adaptations in shoulder rotation motion. Cohort study. Baseball playing field. A total of 210 uninjured male high school baseball pitchers (age = 16 ± 1.1 years, height=1.8±0.1 m, mass=77.5±11.2 kg, pitching experience=6±2.3 years). Using standard goniometric techniques, we measured passive rotational glenohumeral range of motion bilaterally with participants in the supine position. Paired t tests were performed to identify differences in motion between limbs for the group. Analysis of variance and post hoc Tukey tests were conducted to identify differences in motion by age. Linear regressions were performed to determine the influence of chronologic factors on limb motion. Rotation motion characteristics for the population were established. We found no difference between sides for external rotation (ER) at 0° of abduction (t(209) = 0.658, P = .51), but we found side-to-side differences in ER (t(209) =-13.012,P < .001) and internal rotation (t(209) =15.304, P < .001) at 90° of abduction. Age at the time of testing was a significant negative predictor of ER motion for the dominant shoulder (R(2) = 0.019, P = .049) because less ER motion occurred at the dominant shoulder with advancing age. We found no differences in rotation motion in the dominant shoulder across ages (F(4,205) range, 0.451-1.730,P > .05). This range-of-motion profile might be used to assist with the interpretation of normal and atypical shoulder rotation motion in this population. Chronologic characteristics of athletes had no influence on range-of-motion adaptations in the thrower's shoulder.

The Practical Management of Swimmer's Painful Shoulder: Etiology, Diagnosis, and Treatment

Shoulder pain is the most common musculoskeletal complaint in competitive swimmers. Problems with the shoulders of swimmers resemble that of the disabled thrower's shoulder, but the clinical findings and associated dysfunctions are not quite the same. Therefore, swimmers with shoulder pain should be evaluated and treated as a separate clinical entity, aimed toward underlying pathology and dysfunction. Balanced strength training of the rotator cuff, improvement of core stability, and correction of scapular dysfunction is central in treatment and prevention. Technical and training mistakes are still a major cause of shoulder pain, and intervention studies that focus on this are desirable. Imaging modalities rarely help clarify the diagnosis, their main role being exclusion of other pathology. If nonoperative treatment fails, an arthroscopy with debridement, repair, or reduction of capsular hyperlaxity is indicated. The return rate and performance after surgery is low, except in cases where minor glenohumeral instability is predominant. Overall, the evidence for clinical presentation and management of swimmer's shoulder pain is sparse. Preliminary results of an intervention study show that scapular dyskinesis can be prevented in some swimmers. This may lead to a reduction of swimmer's shoulder problems in the future.

The Influence Of Body Composition And Segmental Mass On Kinetic Variables Associated With Youth Throwing Injuries

Incidence of overweightness and obesity have increased dramatically in both adults and children since the mid-1970's. In children, the rate has more than tripled as documented by government agencies. The associated metabolic health risks of obesity are well known, but the risks associated with joint and ligament health remain relatively unknown, especially among overweight children participating in youth sporting activities. The purpose of this study was to investigate the influence of body composition and segmental mass variability on upper extremity ligamentous and joint injuries in youth throwing athletes. 19 youths (age: 14.0 + 1.20 yrs; height: 67.21 + 3.86 in; mass: 68.37 + 18.84 kg) were asked to throw 10 pitches at game speed into a net placed in front of them. Kinetic values at the shoulder and elbow joints were calculated using a VICON motion analysis system. Participant's body and segmental mass and composition were analyzed using a DEXA scan. The study utilized a multivariate correlation (Pearson product correlation; p < .05) and regression framework to investigate the relationship between whole body and throwing arm segmental body mass and composition measures to kinetic variables about the shoulder and elbow. Pearson product correlations revealed significant (p < .01) and positive correlations between each of the peak moment variables about the shoulder (internal rotation moment: 71 + 14 Nm, horizontal adduction moment: 94 + 17 Nm) and elbow (varus moment: 68 + 12 Nm) with each of the whole body and throwing segmental mass variables (body fat percentage: 19.30 + 8.13%; throwing arm mass: 4.1 + 1.30 kg; throwing arm fat percentage: 17.9 + 9.81%; throwing arm length: 26.7 + 2.12 in.), indicating body mass, total fat, arm length, segmental mass, and segmental fat are strongly correlated to peak moment generation about the throwing shoulder and elbow. Lean mass had a marginal significant (p < .1) effect on peak moment generation at the shoulder and elbow. The multivariate regression results showed similar results as the correlations, indicating a strong positive and significant (p < .01) relationship between each of the mass variables to that of the moment variables about the shoulder and elbow. Results suggest, as expected, that body and segmental mass play a significant role in peak moment generation about the throwing shoulder and elbow. Participants who had a greater percentage of fat mass produced greater injury correlated moments about the shoulder and elbow. Further, it should be noted, the segmental lean mass variables indicate that individuals who are fitter (i.e. have better muscle development or less fat mass) may have a reduced injury potential than that of individuals who may have a higher fat composition and less relative muscle mass. The importance of youth fitness levels has been widely documented in previous years. However, there remains a dearth of information on the impact of increased segmental fat mass on musculoskeletal injury risks in youth athletes. The current data set provides evidence that the increased mass due to accumulated fat potentially plays a crucial role in the elevation of shoulder and elbow injuries in youth throwing. Further, coaches should focus not only on improper mechanics, but also on improving the overall fitness level of their athletes.

Glenohumeral Rotational Range of Motion in Collegiate Overhead-Throwing Athletes During an Athletic Season

Repetitive throwing at high velocities leads to altered range of motion (ROM) in the dominant shoulder compared with the nondominant shoulder in overhead-throwing athletes. Loss of glenohumeral internal rotation (IR), or glenohumeral internal-rotation deficit (GIRD), is associated with shoulder injuries. Therefore, GIRD should be evaluated during the clinical examination of the thrower's shoulder. To assess glenohumeral ROM in competitive baseball and softball athletes at 3 intervals over the course of an athletic season in order to (1) examine changes in ROM over time and (2) monitor the prevalence of GIRD. Observational, repeated-measures study. Collegiate athletic training room. Forty-eight healthy National Collegiate Athletic Association (NCAA) Division I or Division II athletes (age = 19 + or - 1 years, height = 174 + or - 14 cm, mass = 77.8 + or - 18.1 kg; 19 softball, 29 baseball players). We measured glenohumeral IR, external rotation (ER), total arc (ER + IR), and GIRD at 3 times: prefall, prespring, and postspring. We calculated GIRD in 2 ways: as the difference in IR between dominant and nondominant shoulders and as the percentage of the total arc. In the dominant shoulder, ER increased during the season (F(2,96) = 17.433, P < .001), but IR remained the same (F(2,96) = 1.839, P = .17). The total arc in the dominant shoulder increased between time intervals (F(2,96) = 14.030, P < .001); the mean difference between prefall and postspring measurements was 9.694 degrees (P < .001), and the mean difference between prefall and postspring measurements was 10.990 degrees (P < .001). In the nondominant shoulder, ER increased over the season (F(2,96) = 23.395, P < .001), but IR did not change over the season (F(2,96) = 0.087, P = .90). The total arc in the nondominant shoulder increased between prefall and prespring measurements and between prefall and postspring measurements (F(2,96) = 18.552, P < .001). No changes were noted in GIRD over time. However, more athletes with GIRD were identified with the GIRD (IR difference) calculation in prefall (n = 6) than in prespring (n = 1) and postspring (n = 4) (Cochran Q = 5.2, P = .07). In addition, more athletes with GIRD were identified with the GIRD (% total arc) calculation in postspring (n = 6) than in prefall (n = 5) or prespring (n = 4) (Cochran Q = 2.6, P = .27). Healthy NCAA Division I and Division II athletes did not display changes in glenohumeral IR over an athletic season. However, they gained in ER and total arc during the season in both shoulders. Future researchers should investigate changes over multiple seasons. The 2 methods of calculating GIRD identified different athletes as having GIRD, indicating that additional investigation is warranted to determine the clinical benefits of each method.

Shoulder Injuries in the Overhead Athlete

The overhead throwing motion is an extremely skillful and intricate movement. When pitching, the overhead throwing athlete places extraordinary demands on the shoulder complex subsequent to the tremendous forces that are generated. The thrower's shoulder must be lax enough to allow excessive external rotation but stable enough to prevent symptomatic humeral head subluxations, thus requiring a delicate balance between mobility and functional stability. We refer to this as the "thrower's paradox." This balance is frequently compromised and believed to lead to various types of injuries to the surrounding tissues. Frequently, injuries can be successfully treated with a well-structured and carefully implemented nonoperative rehabilitation program. The key to successful nonoperative treatment is a thorough clinical examination and accurate diagnosis. Rehabilitation follows a structured, multiphase approach, with emphasis on controlling inflammation, restoring muscles' balance, improving soft tissue flexibility, enhancing proprioception and neuromuscular control, and efficiently returning the athlete to competitive throwing. Athletes often exhibit numerous adaptive changes that develop from the repetitive microtraumatic stresses occurring during overhead throwing. Treatment should include the restoration of these adaptations. Level 5.

Glenohumeral Internal Rotation Deficits in Professional Pitchers Enrolled in an Internal Rotation Stretching Program

Background Repetitive throwing motion creates increased external rotation and decreased internal rotation in the glenohumeral joint. There is controversy regarding the contribution of osseous and soft tissue adaptations to these changes in rotation. Objective To evaluate internal rotation deficits in the professional baseball thrower's shoulder and determine the impact of an internal rotation stretch program on that deficit. Study Design Cross-sectional study; Level of evidence, 3. Methods Eighty-five male professional pitchers were evaluated in this study. Players were divided into 2 groups based on length of participation in an appropriate internal rotation stretch program. Data were collected on internal and external rotations and total range of motion in both dominant and nondominant arms using a goniometer. Internal rotation deficit (the lack of internal rotation relative to the opposite side) was calculated. Generalized comparative statistical tests were used. Results Pitchers with 3 or more years in a stretch program (group 1) had greater internal rotation (74.3° vs 54.3°) and greater total range of motion (217.0° vs 194.2°) in dominant shoulders than did pitchers with less than 3 years (group 2). Total range of motion was greater in the dominant than in the nondominant arm for group 1. Internal rotation deficit in dominant arms was significantly greater for group 2 than for group 1. The analysis of dominant arm rotation relative to years in an internal rotation stretching program for pitchers in both groups showed a progressive increase in both internal rotation and total arc of motion with the number years in such a program plateauing after year 3. Conclusion The throwing motion shifts the total arc of motion toward external rotation and diminishes internal rotation. The increased external rotation may be attributable to increased humeral retroversion. The internal rotation deficit, however, is caused by soft tissue adaptations that can be addressed by consistent participation in a stretching program focused on internal rotation.

L'épaule du lanceur

Several theories have been developed to better understand the throwing movement. Many are contradictory and have long been based on unconvincing anatomic assumptions. Considering the large amount of experience accumulated in North America, it would appear useful to develop a new concept which could be a truly useful clinical tool for understanding and treating shoulder disorders in throwers. The gravity of shoulder disorders in throwers results from the development of an intra-articular glenohumeral injury. Shoulders considered at risk present defective RI2 and/or a SICK scapula. Nevertheless, the large majority of patients can respond to rehabilitation therapy combining a more or less intensive stretching program for the postero-inferior capsule with scapula rehabilitation exercises. Surgical treatment of the thrower's shoulder is specifically and exclusively arthroscopic. In addition, no clinical test for intra-articular injuries in this context has proven specificity or sensitivity. Similarly, care should be taken to assess the meaning of different arthroMRI or arthroCTscann diagnosis for those injury. A careful clinical assessment is necessary to understand the meaning of different radiological descriptions of glenoid rim injuries. Thus, exploratory arthroscopy, which is in reality proposed when medical treatment has failed after a period of time, can identify the cause of injury and at the same time enable its treatment.

Path of Glenohumeral Articulation Throughout the Rotational Range of Motion in a Thrower's Shoulder Model

Background Overhead-throwing athletes have increased external and diminished internal glenohumeral rotation that may alter glenohumeral kinematics. Purpose To quantify the kinematic changes present in a cadaveric model of a thrower's shoulder. Study Design Controlled laboratory study. Methods In 8 fresh-frozen cadaveric shoulders, the rotator cuff and overlying muscles were removed, and the glenohumeral capsule, coracoacromial ligament, and coracohumeral ligament were left intact. The scapula was fixed, and the humerus was placed in 90° of shoulder abduction in a 6 degrees of freedom testing device. A compressive force of 44 N was applied. A thrower's shoulder model was created, and sequential conditions were examined: intact, after anterior stretching, and after the addition of posterior-inferior capsular plication. Kinematic measurements were obtained through a complete range of glenohumeral rotation. Results Glenohumeral external rotation increased 16%, from 149° to 173° (P <. 001), after stretching in external rotation and remained increased by 11% to 166° (P <. 001) after posterior-inferior capsular plication. With the addition of the posterior-inferior capsular plication, internal rotation averaged 7°, which was not significantly different from the intact state (11°, P =. 55) or the stretched state (16°, P =. 07). The total glenohumeral rotation after stretching followed by posterior-inferior capsular plication did not differ significantly from intact state (P =. 25). At maximum external rotation, the humeral head apex was shifted posteriorly in the stretched (P =. 003) and plicated (P <. 001) states compared with the intact state. The humeral head apex was posteriorly displaced at 135° and 150° of external rotation compared with the intact condition (P =. 039 and. 049, respectively). In maximum internal rotation, anterior stretching had no significant effect on the humeral head apex position. However, after posterior-inferior capsular plication, the humeral head apex was significantly shifted inferiorly (P =. 005) and anteriorly (P =. 03) in maximum internal rotation compared with the intact state. Conclusion Significant changes in glenohumeral motion occur in this model during the simulated late-cocking and follow through phases of throwing. In this model, posterior capsular tightness alters the humeral head position most profoundly during the deceleration and follow-through phases of throwing.

Development of cadaveric models of a thrower’s shoulder

Two novel cadaveric models of a thrower's shoulder were evaluated. Both models included the capsuloligamentous and osseous components of the glenohumeral joint. In model 1 the coracohumeral ligament was retained and the glenoid was positioned parallel to the ground whereas the humerus was positioned at 60 degrees of glenohumeral elevation in the scapular plane. In model 2 the coracohumeral ligament was resected and the glenoid was positioned vertically at 30 degrees of scapular elevation whereas the humerus was positioned at 60 degrees of glenohumeral elevation in the scapular plane. Each specimen was sequentially tested under 3 conditions: intact, after nondestructive anterior capsular stretch, and after simulated posterior capsular contracture. Measurements included rotational range of motion and relative glenohumeral position from neutral to maximum external rotation of the humerus. In model 2 the glenohumeral forces were also measured by use of a 6-degree-of-freedom load cell. The stretching of the anterior capsule in model 1 was performed while the humeral head was constrained in the glenoid and in model 2 while the humeral head was unconstrained. Both models showed increased humeral external rotation and decreased humeral internal rotation similar to that seen in throwing athletes. Both models also showed an increased humeral shift inferiorly after anterior capsular stretching. Model 1 demonstrated a subsequent humeral shift superiorly after posterior capsule plication. Unconstrained specimens of model 2 dislocated posteriorly and inferiorly after posterior capsule plication when the humerus was rotated to maximum external rotation. On the basis of these findings, for future studies, constrained capsular stretching models will be further investigated.

Significance of the Estimation of Muscle Power of External rotation in the Zero Position in a Throwing Shou lder

Significance of the Estimation of Muscle Power of External rotation in the Zero Position in a Throwing Shou lder

Current concepts in the rehabilitation of the overhead throwing athlete.

The overhead throwing motion is an extremely skillful and intricate movement that is very stressful on the shoulder joint complex. The overhead throwing athlete places extraordinary demands on this complex. Excessively high stresses are applied to the shoulder joint because of the tremendous forces generated by the thrower. The thrower's shoulder must be lax enough to allow excessive external rotation, but stable enough to prevent symptomatic humeral head subluxations, thus requiring a delicate balance between mobility and functional stability. We refer to this as the "thrower's paradox." This balance is frequently compromised, which leads to injury. Numerous types of injuries may occur to the surrounding tissues during overhead throwing. Frequently, injuries can be successfully treated with a well-structured and carefully implemented nonoperative rehabilitation program. The key to successful nonoperative treatment is a thorough clinical examination and accurate diagnosis. Athletes often exhibit numerous adaptive changes that develop from the repetitive microtraumatic stresses observed during overhead throwing. Treatment should focus on the restoration of these adaptations during the rehabilitation program. In this article, the typical musculoskeletal profile of the overhead thrower and various rehabilitation programs for specific injuries are discussed. Rehabilitation follows a structured, multiphase approach with emphasis on controlling inflammation, restoring muscle balance, improving soft tissue flexibility, enhancing proprioception and neuromuscular control, and efficiently returning the athlete to competitive throwing.

Treatment of rotator-cuff pathologyin throwing athletes

The throwing athlete's shoulder is unique in many ways. The forces generated in the rotator cuff are extreme and can lead to injury due to either compression or tension. The evaluation of the thrower's shoulder must take into account the abnormalities inherent to these athletes. The information presented here represents our approach to throwers and the rotator cuff problems which are commonly encountered. Of particular importance is the attempt to treat every thrower conservatively. Only after failure of conservative measures will surgical intervention be considered. At the time of surgery, efforts are directed at not only relieving pain but also correcting any underlying pathology as it relates to pathologic laxity.

A Case Report ; Painful Throwing Shoulder Accompanied by a Peculiar Glenoid Osteochondral Injury

A Case Report ; Painful Throwing Shoulder Accompanied by a Peculiar Glenoid Osteochondral Injury

Clinical relevance of dysfunction of scapular upward rotation in painful throwing shoulders

Clinical relevance of dysfunction of scapular upward rotation in painful throwing shoulders

Injuries to the shoulder in the throwing athlete. Part two: evaluation/treatment.

In part one of this three-part series (March/April 2000), I concentrated on summarizing the biomechanics of the normal throwing shoulder and the pathophysiology of injury. A classification of injury was presented that was based on the principles contained in that article. Part two of this series will focus on the evaluation and treatment of injuries, expanded from an understanding of the principles learned in part one. The ability to perform a skillful examination, and thus develop an accurate diagnosis, is the foundation for treatment. Fortunately, many difficulties encountered in a thrower's shoulder can be treated with a nonoperative approach. However, in instances where conservative measures fail, an improved understanding of the pathophysiology of injury and the development of improved surgical techniques are leading to more accurate diagnoses and more successful rates of return of the athlete to a premorbid level of activity.