Preseason shoulder range of motion screening and in-season risk of shoulder and elbow injuries in overhead athletes: systematic review and meta-analysis.

OBJECTIVE: To characterise whether preseason screening of shoulder range of motion (ROM) is associated with the risk of shoulder and elbow injuries in overhead athletes. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Six electronic databases up to 22 September 2018. ELIGIBILITY CRITERIA: Inclusion criteria were (1) overhead athletes from Olympic or college sports, (2) preseason measures of shoulder ROM, (3) tracked in-season injuries at the shoulder and elbow, and (4) prospective cohort design. Exclusion criteria were (1) included contact injuries, (2) lower extremity, spine and hand injuries, and (3) full report not published in English. RESULTS: Fifteen studies were identified, and they included 3314 overhead athletes (baseball (74.6%), softball (3.1%), handball (16.1%), tennis (2.0%), volleyball (2.0%) and swimming (2.2%)). Female athletes are unrepresented (12% of the overall sample). Study quality ranged from 11 to 18 points on a modified Downs and Black checklist (maximum score 21, better quality). In one study, swimmers with low (<93°) or high (>100°) shoulder external rotation were at higher risk of injuries. Using data pooled from three studies of professional baseball pitchers, we showed in the meta-analysis that shoulder external rotation insufficiency (throwing arm <5° greater than the non-throwing arm) was associated with injury (odds ratio=1.90, 95% confidence interval 1.24 to 2.92, p<0.01). CONCLUSION: Preseason screening of shoulder external rotation ROM may identify professional baseball pitchers and swimmers at risk of injury. Shoulder ROM screening may not be effective to identify handball, softball, volleyball and tennis players at risk of injuries. The results of this systematic review and meta-analysis should be interpreted with caution due to the limited number of studies and their high degree of heterogeneity. PROSPERO REGISTRATION NUMBER: CRD42017072895.

Biomechanical Comparison of Knotless All-Suture Anchors and Knotted All-Suture Anchors in Type II SLAP Lesions: A Cadaveric Study.

PURPOSE: To compare the biomechanical performance of knotless versus knotted all-suture anchors for the repair of type II SLAP lesions with a simulated peel-back mechanism. METHODS: Twenty paired cadaveric shoulders were used. A standardized type II SLAP repair was performed using knotless (group A) or knotted (group B) all-suture anchors. The long head of the biceps (LHB) tendon was loaded in a posterior direction to simulate the peel-back mechanism. Cyclic loading was performed followed by load-to-failure testing. Stiffness, load at 1 and 2 mm of displacement, load to repair failure, load to ultimate failure, and failure modes were assessed. RESULTS: The mean load to repair failure was similar in groups A (179.99 ± 58.42 N) and B (167.83 ± 44.27 N, P = .530). The mean load to ultimate failure was 230 ± 95.93 N in group A and 229.48 ± 78.45 N in group B and did not differ significantly (P = .958). Stiffness (P = .980), as well as load at 1 mm (P = .721) and 2 mm (P = .849) of displacement, did not differ significantly between groups. In 16 of the 20 specimens (7 in group A and 9 in group B), ultimate failure occurred at the proximal LHB tendon. Failed occurred through slippage of the labrum in 1 specimen in each group and through anchor pullout in 2 specimens in group A. CONCLUSIONS: Knotless and knotted all-suture anchors displayed high initial fixation strength with no significant differences between groups in type II SLAP lesions. Ultimate failure occurred predominantly as tears of the proximal LHB tendon. CLINICAL RELEVANCE: All-suture anchors have a smaller diameter than solid anchors, can be inserted through curved guides, preserve bone stock, and facilitate postoperative imaging. There is a paucity of literature investigating the biomechanical capacities of knotless versus knotted all-suture anchors in type II SLAP repair.

Injury Occurrence in Male Handball Players and its Impact on Physical Constitution.

In male handball, limited knowledge exists about the body posture and postural control in correlation to their injury occurrence and their impact on physical constitution. 91 male handball players participated and were asked about playing position and years, NSAIDs intake, sustained injuries and therapy duration. A three-dimensional back scanner and a pressure measuring plate were used. Shoulder injuries cause a differing scapular height and increase the vertebrae rotation in correlation to playing years. Lower limb injuries lead to a decrease on the Centre of Pressure (CoP) with growing game experience. Wing players show the lowest injury risk. Lower limb and shoulder girdle are mostly affected regarding the incidence of injuries. Pivot players suffer most injuries in the lower limb area (59%), whereas wing players mostly have shoulder injuries (19%). Being injured, 21% of the players continue playing, 79% pause for a minimum of six months (25%). No correlation can be determined between level of profession, use of NSAIDs and body posture or postural control. Playing position, employment situation or NSAIDs have no influence on type of injury, body posture or postural control. While shoulder injuries can be recognized in the vertebrae area, lower limb injuries can affect the CoP.

Decreased external rotation strength is a risk factor for overuse shoulder injury in youth elite handball athletes.

PURPOSE: Overuse shoulder injuries are common in youth handball, but research is limited. The purpose of this study was to identify pre-season risk factors associated with overuse shoulder injuries in this population. METHODS: One-hundred and thirty-eight (70 boys and 68 girls) youth elite players (age 14.1 ± 0.8 years, height 175.2 ± 8.2 cm, weight 64.0 ± 9.6 kg) completed a pre-season screening protocol. Passive glenohumeral range of motion and maximum external (ER) and internal rotation (IR) strength were measured with a manual goniometer and a hand-held dynamometer. Scapular dyskinesia and maximum throwing velocity were also assessed. Players completed standardised questionnaires over the 2017-2018 season and reported any overuse shoulder symptoms. RESULTS: Decreased isometric and eccentric ER strength was identified as a risk factor for overuse shoulder injury, both for absolute (OR 10.70, 95% CI 1.2-95.6, p = 0.034) and normalised ER strength (OR 1.2, 95% CI 1.0-1.4, p = 0.015) and the ER:IR strength ratio (OR 1.2, 95% CI 1.1-1.5, p = 0.012). ER gain of more than 7.5° (p = 0.025) and GIRD of more than 7.5° (p = 0.014) were identified as risk factors for overuse shoulder injury in girls. Scapular dyskinesia (OR 1.1, n.s.) and maximum throwing velocity did not seem to contribute to injury risk. The average response rate was 63%. CONCLUSION: In elite youth handball, deficits in ER strength is a risk factor for overuse shoulder injury for both sexes; ER gain and GIRD are only risk factors for girls. Focused pre-season assessments may aid the identification of risk factors for shoulder overuse injuries and the application of specific programmes to reduce risk. LEVEL OF EVIDENCE: II.

Does scapular corrective taping alter periscapular muscle activity and 3-dimensional scapular kinematics? A systematic review.

STUDY DESIGN: This is a systematic review. INTRODUCTION: Scapular taping is widely used in the management of scapular dysfunction. However, its effects on the scapular kinematics and the electromyography (EMG) activity of the periscapular muscles are not clear. PURPOSE OF THE STUDY: The purpose of the study was to systematically review the current literature to examine whether scapular corrective taping alters the EMG activity of the periscapular muscles and the 3-dimensional scapular kinematics. METHOD: MEDLINE and Web of Science databases were searched using specific mesh terms up to April 2018. A hand search was also conducted on the reference list of the included articles. A total of 157 studies were identified, and they were further analyzed for the eligibility to the systematic review. Studies that investigated the effects of scapular corrective taping on the EMG activity of the periscapular muscles and on the 3-dimensional scapular kinematics on patients with shoulder problems or asymptomatic subjects were eligible for the systematic review. The Cochrane Effective Practice and Organization of Care criteria were modified and used for the risk-of-bias assessment. RESULTS: Eleven articles met the inclusion criteria and were included in the systematic review. Five studies investigated the effects of corrective taping on the scapular kinematics and 8 studies reported the effects of corrective taping on the EMG activity of the periscapular muscles. There was an agreement among the studies that scapular upward rotation is increased with the corrective taping, while there are inconsistent results concerning the scapular external rotation and posterior tilt. In addition, studies mostly reported that corrective taping decreases the activity of the upper trapezius, while it has conflicting effects on the activity patterns of other periscapular muscles. DISCUSSION: Scapular corrective taping was found to increase the scapular upward rotation; however, its effects on scapular external rotation and posterior tilt are controversial. It was also found that corrective taping might decrease the EMG activity of the upper trapezius, while it had no effects on the activity of lower trapezius, and its effects on other periscapular muscles were controversial. CONCLUSION: The results of the studies indicated that scapular corrective taping might alter the 3-dimensional scapular kinematics, while there are controversies about the effects of corrective taping on the EMG activity of the periscapular muscles. Further studies are needed to clarify the conflicts.

Three-Dimensional Analysis of Scapular Kinematics During Arm Elevation in Baseball Players With Scapular Dyskinesis: Comparison of Dominant and Nondominant Arms.

BACKGROUND: The knowledge of 3-dimensional scapular kinematics is essential for understanding the pathological lesions of the shoulder and elbow in throwing athletes. Many studies about alterations of the resting scapular position, dynamic scapular motion, or scapular dyskinesis (SD) have been conducted, yet none of them have identified a consistent pattern of altered scapular kinematics in throwing athletes. Hypothesis/Purpose: To analyze the 3-dimensional scapular kinematics of dominant and nondominant arms in baseball players with a pathological condition of the shoulder or elbow. STUDY DESIGN: Cross-sectional study. METHODS: Bilateral scapular positions, consisting of upward rotation (UR), superior translation (ST), internal rotation (IR), protraction (PRO), and anterior tilting (AT) with an arm at rest and at 150° forward elevation, were measured among 319 baseball players with SD using 3-dimensional computed tomography. Angular values of scapula were compared between dominant and nondominant arms with statistical analysis. LEVEL OF EVIDENCE: Level III, diagnostic study. RESULTS: The scapular position of dominant arms showed significantly more AT, less ST at rest and more UR and IR and less ST, PRO, and AT at 150° full forward elevation compared with the nondominant arms. The magnitude of mean change of UR, IR, PRO, and AT during arm elevation increased significantly between the paired arms (P value: UR, ST, PRO, and AT: <.001 and IR: .001). CONCLUSION: When compared with the nondominant arms, UR, AT, and PRO with the arm at 150° forward elevation of dominant symptomatic arms in baseball players tilted toward positive compensation, whereas IR altered toward negative decompensation. In addition, the angular increment of the scapula increased significantly in dominant symptomatic arms compared with the nondominant arms.

Professional advancement, performance, and injury characteristics of baseball players entering the Major League Baseball draft after treatment for shoulder injuries.

BACKGROUND: How shoulder injuries treated before the Major League Baseball (MLB) draft affect the player's performance over their career is unclear. The purpose of this study was to determine whether prior shoulder injuries were associated with a difference in the level of performance and advancement of MLB draftees. METHODS: Before entering the draft, 119 professional baseball players from 2004 to 2010 were treated for a shoulder injury (73% treated surgically) as an amateur. A 3:1 matched case-control was performed to players without prior shoulder injuries by age, position, round selected, and signing bonus. Follow-up data were collected in 2016, and professional advancement, disabled list time, and in-game performance statistics for pitchers were analyzed and compared. RESULTS: Players with a prior shoulder injury had a statistically higher chance to be assigned to the disabled list then controls (P = .03), but there was no difference in disabled list time or professional advancement. Pitchers with a prior shoulder injury pitched a statistically lower number of innings per game than controls (P = .04). All other in-game performance statistics were not statistically different. The type of treatment did not have any effect on future performance or advancement. CONCLUSIONS: Professional baseball players treated for prior shoulder injuries at the amateur level were more likely to sustain future disability than their matched controls, but it did not affect professional advancement.

The infraspinatus test may not be used to screen for shoulder external rotator strength deficits among patients with shoulder pathology.

BACKGROUND: The infraspinatus test is often used to determine the presence of shoulder external rotator strength deficits. As the accuracy of this test has not been established adequately, the purpose of this study was to determine the accuracy of the infraspinatus test in detecting shoulder external rotator strength deficits. METHODS: Sixty-two patients with a unilateral shoulder disorder underwent the infraspinatus test followed by instrumented assessment of shoulder external rotator muscle strength. The infraspinatus test was rated positive or negative based on the presence or absence of a strength deficit on the involved compared with the uninvolved shoulder. The instrumented strength assessment was rated positive or negative based on 4 cutoff thresholds for the presence of a strength deficit on the involved side: ≥10%, ≥15%, ≥20%, or ≥30%. The Sensitivity, specificity, positive and negative likelihood ratio of the infraspinatus test was determined based on each cutoff threshold. RESULTS: Sensitivity ranged from 52.5 to 61.1%, specificity ranged from 72.7 to 90.9%, the positive likelihood ratio ranged from 2.24 to 5.77, while the negative likelihood ratio ranged from 0.52 to 0.59. CONCLUSIONS: As considerable external rotator strength deficits may frequently exist among patients with a negative infraspinatus test, this test may not serve a good screening test for external rotator strength deficits. Contrarily, clinicians can be reasonably certain of the presence of an external rotator strength deficit given a positive infraspinatus test.

Isolated Infraspinatus Atrophy Secondary to Suprascapular Nerve Neuropathy Results in Altered Shoulder Muscles Activity.

CONTEXT: Isolated infraspinatus atrophy (IIA) is a common condition among overhead activity athletes, which affects the hitting shoulder and is caused by suprascapular nerve injury. The loss of infraspinatus function could lead to altered activity of the glenohumeral and scapulothoracic (ST) muscles and compromise the optimal shoulder function. OBJECTIVE: To assess the surface electromyographic (sEMG) activity patterns, relationships, and response latencies of relevant shoulder girdle muscles in professional volleyball players with IIA and in healthy control players. DESIGN: Cross-sectional study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-four male professional volleyball players (12 players with diagnosed IIA and 12 healthy players) recruited from local volleyball teams. INTERVENTION(S): sEMG activity of anterior, middle, and posterior deltoid; upper, middle, and lower trapezius; and serratus anterior (SA) was recorded and evaluated during a movement of shoulder abduction in the scapular plane, monitored with an optoelectronic motion capture system. MAIN OUTCOME MEASURE(S): sEMG activity, relationships, and response latencies of the selected muscles were analyzed with analysis of variance models to highlight statistical differences within and between groups. RESULTS: Athletes with IIA demonstrated significant higher deltoid and trapezius muscles activity and lower SA activity compared with the contralateral shoulder and healthy athletes. The shoulder with IIA also showed a higher activity ratio between the upper trapezius and other ST muscles in addition to anticipated activation of the upper trapezius and delayed activation of the SA, with regard to the onset of shoulder movement. CONCLUSIONS: This study highlighted altered shoulder muscle activity levels, ST muscles imbalances, and abnormal ST recruitment patterns in the hitting shoulder of professional volleyball players with IIA, secondary to suprascapular nerve neuropathy. Such shoulder girdle muscles' impairments may compromise the optimal scapulohumeral rhythm and function, increasing the risk of acute and overuse shoulder injuries.

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.

The effectiveness of conservative and surgical treatment for shoulder stiffness: a systematic review of current literature.

Introduction: Currently, no therapeutic intervention is universally accepted, and the most effective management for restoring motion and diminishing pain in patients with shoulder stiffness has yet to be defined. This systematic review analyses outcomes of conservative and surgical interventions to treat shoulder stiffness. Source of data: A systematic review of literature according to the PRISMA guidelines was performed. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, Ovid and Google Scholar databases using various combinations of the keywords 'shoulder', 'shoulder stiffness', 'stiff shoulder', 'conservative', since inception of databases to June 2018 was performed. Areas of agreement: Shoulder stiffness could be treated with conservative means including nonsteroidal anti-inflammatory medications, corticosteroid injections, or transcutaneous electrical nerve stimulation, manipulation under anaesthesia, and arthroscopic capsular release. Areas of controversy: No therapeutic intervention is universally accepted, and the most effective management to restore motion and diminish pain in patients with shoulder stiffness has yet to be defined. Growing points: The rate of failure after treatment for stiff shoulder is higher in the surgical group than in the conservative group. Areas timely for developing research: There is insufficient evidence to establish whether surgical or conservative management is the best choice to manage shoulder stiffness. Prospective, randomized studies are needed to establish whether surgical or conservative management produce a clinically relevant difference in functional outcome.

Many Shoulder MRI Findings in Elite Professional Throwing Athletes Resolve After Retirement: A Clinical and Radiographic Study.

BACKGROUND: Anatomic findings on MRI scans of the shoulder likely affect patients differently based on their physical demands and fitness levels. The natural history of these anatomic findings once professional overhead athletes retire remains unclear. A better understanding of what happens with these findings after retirement may influence how we manage shoulder problems in athletes. PURPOSE: (1) What is the natural history of MRI-observed findings in the throwing and nonthrowing shoulders of professional European handball players after retirement from the sport? What proportion of these individuals have diagnosable findings on MRI, and do these findings disappear after retirement? (2) Do clinical findings such as Constant and Murley score and shoulder ROM change after retirement in these professional overhead athletes? METHODS: The inception cohort of this series consisted of the entire Swiss National European handball team except the goalkeepers. These 30 professional players also played in the highest Swiss handball league in 2001. None of these players previously had shoulder surgery. During their career, they had a clinical assessment and bilateral shoulder MRI as part of an earlier study. We sought to evaluate the players who had retired and did not have a history of shoulder surgery, to evaluate the natural history of MRI-observed findings made in the initial study during their professional career. Of the 30 players, 10 were excluded (four continued to play professionally, four declined participation, and two had surgery after the initial study), leaving 20 (66%) for analysis at a mean of 6 years (SD, 3 years) after retirement. To gain a better understanding of the evolution of these MRI findings in the longer-term, we also evaluated 18 additional former professional European handball players who did not have any history of shoulder surgery, had all played in the highest Swiss league and for the National Team, and had terminated their career at a mean of 15 years (SD, 3 years) ago. All the subjects in both study groups (those at 6 and 15 years after retirement) underwent a detailed interview, standardized clinical examination including ROM measurements, collection of the Constant and Murley scores and the subjective shoulder value of both shoulders, and bilateral shoulder MRI. MRI findings (consisting of abnormalities and normal variations) were reported as radiographic diagnoses, independent of the potential that these findings could be considered normal variations in people in this age group. RESULTS: At the initial MRI evaluation, the proportion of active professional European handballers with diagnosable MRI findings in the throwing shoulder was 19 of 20 (95%) and for the handballers with nonthrowing shoulders was 17 of 20 (85%), while 15 years after retirement, both shoulders of all subjects showed MRI findings. None of the rotator cuff tears progressed to full-thickness tears after retirement. In the throwing shoulders, we observed fewer individuals with ganglion cysts larger than 5 mm (initial followup: six of 20 [30%] versus 6 years after retirement: 0 of 20 (0%); odds ratio, 14.5; [95% CI, 0.7-283]; p = 0.044). The Constant and Murley score increased in the throwing shoulder from 93 points (SD, 6 points) at initial followup to 98 points (SD, 3 points) at a mean of 6 years after retirement (mean difference, 5 points; SD, 5 points; 95% CI, 2.5-7.4; p < 0.001), and to 97 points (SD, 3 points) at a mean of 15 years after retirement. However these differences are below the typically reported minimum clinically important difference for the Constant and Murley score, and so are unlikely to be clinically relevant. External rotation in 90° abduction remained increased in the throwing shoulder compared with the nonthrowing shoulder up to 15 years after retirement (initial followup: mean difference, 8°; p = 0.014; 15 years after retirement: mean difference, 4°; SD, 15; p = 0.026). Internal rotation remained decreased in the throwing compared with the nonthrowing shoulders (during the career: mean difference, 5° [SD, 10°], p = 0.036; 15 years after retirement: mean difference, 3° [SD, 4°], p = 0.021). CONCLUSIONS: Our data suggest that findings of the throwing shoulder like partial rotator cuff tears, bony cysts and ganglions do not progress after retirement, and sometimes they resolve. Because of this and because many MRI changes correlate poorly with clinical symptoms, the indication for surgical treatment of these findings should be questioned very carefully. LEVEL OF EVIDENCE: Level II, prognostic study.

The epidemiology of MRI detected shoulder injuries in athletes participating in the Rio de Janeiro 2016 Summer Olympics.

BACKGROUND: To use Magnetic Resonance Imaging (MRI) to characterize the severity, location, prevalence, and demographics of shoulder injuries in athletes at the Rio de Janeiro 2016 Summer Olympic Games. METHODS: This was a retrospective analysis of all routine shoulder MRIs obtained from the Olympic Village Polyclinic during the Rio 2016 Summer Olympics. Imaging was performed on 1.5 T and 3 T MRI, and interpretation was centrally performed by a board-certified musculoskeletal radiologist. Images were assessed for tendon, muscle, bone, bursal, joint capsule, labral, and chondral abnormality. RESULTS: A total of 11,274 athletes participated in the Games, of which 55 (5%) were referred for a routine shoulder MRI. Fifty-three (96%) had at least two abnormal findings. Seven (13%) had evidence of an acute or chronic anterior shoulder dislocation. Forty-nine (89%) had a rotator cuff partial tear and / or tendinosis. Subacromial / subdeltoid bursitis was present in 29 (40%). Thirty (55%) had a tear of the superior labrum anterior posterior (SLAP). CONCLUSION: Our study demonstrated a high prevalence of both acute and chronic shoulder injuries in the Olympic athletes receiving shoulder MRI. The high rates of bursal, rotator cuff, and labral pathology found in these patients implies that some degree of glenohumeral instability and impingement is occurring, likely due to fatigue and overuse of the dynamic stabilizers. Future studies are needed to better evaluate sport-specific trends of injury.

Type VIII SLAP Repair at Midterm Follow-Up: Throwers Have Greater Pain, Decreased Function, and Poorer Return to Play.

PURPOSE: To evaluate and compare midterm outcomes and return to play (RTP) of throwers and nonthrowers who underwent type VIII SLAP repair. METHODS: With 4-year minimum follow-up, stability, pain, range of motion (ROM), Kerlan-Jobe Orthopaedic Clinic (KJOC), and American Shoulder and Elbow Surgeons (ASES) scores; surgical satisfaction; and RTP were compared between throwing and nonthrowing athletes who underwent repair of type VIII SLAP lesions between 2003 and 2014. RESULTS: 46 patients (27 throwers and 19 nonthrowers) were included. The athletes were aged 24.2 ± 9.2 years at the time of surgery. The mean follow-up period was 6.6 ± 2.0 years. A significant improvement in stability, pain, ROM, KJOC, and ASES scores was seen after surgery in both throwers and nonthrowers (P < .05). When postoperative outcomes were compared, throwers had more pain (P = .047), decreased ROM (P = .03), lower KJOC scores (52.2 ± 24.0 in throwers vs 87.5 ± 18.8 in nonthrowers, P < .0001), and lower ASES scores (43.5 ± 7.1 in throwers vs 48.3 ± 3.0 nonthrowers, P = .02). There was no difference in stability (P = .06), surgical satisfaction (96.3% in throwers vs 100% in nonthrowers, P > .99), or overall RTP (70.4% in throwers vs 94.7% in nonthrowers, P = .06). However, throwers were less likely to RTP at their preoperative level (37.0% in throwers vs 73.7% in nonthrowers, P = .02). CONCLUSIONS: Surgical repair of type VIII SLAP tears led to significant improvements in stability, pain, ROM, and outcome scores at midterm follow-up. Compared with nonthrowers, throwers had significantly more pain, less ROM, and worse function. Throwers were also less likely to RTP at their preoperative level. These findings suggest that type VIII SLAP tears should be repaired in all athletes because outcomes do improve, although throwers require specific counseling and expectation management regarding their ability to RTP at their preinjury level. LEVEL OF EVIDENCE: Level III, therapeutic case-control study.

The Superior Glenohumeral Joint Capsule Alone Does Not Prevent Superior Translation of the Humeral Head: An In Vitro Biomechanical Study.

PURPOSE: To answer 2 questions: What is the main structure that prevents the superior translation of the humeral head, the supraspinatus or the superior capsule (SC)? And what mechanism does the principal structure rely on to prevent the superior translation of the humeral head, the spacer effect or the tensional hammock effect? METHODS: Eight shoulder specimens were assessed using a custom biomechanical testing system. Glenohumeral superior translation and subacromial peak pressure were compared using 6 models: the intact joint model, supraspinatus dysfunction model, supraspinatus defect model, SC tear model, SC defect model, and irreparable rotator cuff tear (IRCT) model. RESULTS: Compared with the intact joint model, the supraspinatus defect model significantly increased the superior translation (by 2.6 mm; P < .001) and subacromial peak pressure (by 0.43 MPa; P = .013) at 0° glenohumeral abduction, while the SC defect model unremarkably altered the superior translation at 0° (by 0.6 mm; P = .582) and 45° (by 0.3 mm; P = .867) of glenohumeral abduction and the subacromial peak pressure at 0° (by 0.11 MPa; P = .961), 30° (by -0.03 MPa; P = .997), and 45° (by -0.33 MPa; P = .485) of glenohumeral abduction. The supraspinatus dysfunction model significantly increased the superior translation at 0° (by 1.7 mm; P < .001), 30° (by 1.2 mm; P = .005), and 45° (by 0.8 mm; P = .026) of glenohumeral abduction, but not the subacromial peak pressure compared with the intact joint model. However, no significant differences were found between the supraspinatus defect model and the supraspinatus dysfunction model with respect to the superior translation or subacromial peak pressure (all P > .05). CONCLUSIONS: The anatomic SC has a negligible role in preventing the superior translation of the humeral head. CLINICAL RELEVANCE: SC reconstruction is not a simple anatomic reconstruction, and its promising clinical outcome may be due to tensional fixation technique and choice of graft.

Rotational glenohumeral adaptations are associated with shoulder pathology in professional male handball players.

PURPOSE: Glenohumeral range of motion adaptations may affect throwing athletes and contribute to shoulder injury. The purpose of this study was to evaluate shoulder rotation deficits among elite professional handball players and its correlation to the presence of shoulder pain and morphological changes. METHODS: Eighty-seven elite professional handball players and 41 healthy non-athlete volunteers participated in the study. Evaluations included measurement of range of internal and external rotation, total arch of motion, identification of shoulder pain and ultrasound scan for diagnosis of rotator cuff tears and internal impingement. RESULTS: Glenohumeral rotational deficits (>20-25°) were found among 11 players group (13%). The throwing shoulders in the players group showed a decrease in internal rotation and an increase in external rotation with significantly larger ranges among players compared to the non-athlete group. Internal rotation deficit >20° was associated with higher incidence of shoulder pain among players. Both internal rotation deficits (>25°) and total arch of motion deficit (>20°) co-existed with higher incidence of internal impingement. Shoulder pain was common (36/97-41%) and was associated with decreased external rotation and total arch of motion. Internal impingement (found in 13/87-15%) correlated with decreased rotation ranges and a greater deficit in total arch of motion, whereas higher gain in external rotation correlated with a partial rotator cuff tear (found in 12/87-14%). CONCLUSIONS: Shoulder pathologies and problems commonly affected the group of handball players. Greater glenohumeral rotational deficits in throwing shoulders of handball players correlate with shoulder pain and internal impingement, while increased external rotation with partial rotator cuff tears. Such deficits affect 13% of the athlete population. Major clinical relevance of the study is to monitor handball players' shoulders both clinically and by proper imaging. Evaluation of range of rotation seems to identify shoulders at risk of the pathology. LEVEL OF EVIDENCE: Cross-Sectional study with control group, Level II.

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.

[Arthroscopic-assisted stabilization of medial shoulder instability in a Miniature Poodle]. / Arthroskopisch-assistierte Stabilisation einer medialen Schulterinstabilität bei einem Zwergpudel.

INTRODUCTION: A 12-year old female miniature Poodle was presented because of a 4/4 right fore-limb lameness. The orthopedic examination demonstrated pain at palpation of the right shoulder and an abduction angle of 55 °. MRI examination confirmed injuries consistent with a traumatic medial shoulder instability with no evidence of shoulder dysplasia. A partial rupture of the subscapularis tendon and complete detachment of the cranial gleno- humeral ligament were confirmed with arthroscopy. The joint was successfully stabilized using an arthroscopic assisted prosthetic suture.

Shoulder and Lower Back Joint Reaction Forces in Seated Double Poling.

Overuse injuries in the shoulders and lower back are hypothesized to be common in cross-country sit-skiing. Athletes with reduced trunk muscle control mainly sit with the knees higher than the hips (KH). To reduce spinal flexion, a position with the knees below the hips (KL) was enabled for these athletes using a frontal trunk support. The aim of the study was to compare the shoulder joint (glenohumeral joint) and L4-L5 joint reactions of the KL and KH sitting positions. Five able-bodied female athletes performed submaximal and maximal exercise tests in the sitting positions KL and KH on a ski ergometer. Measured pole forces and 3-dimensional kinematics served as input for inverse-dynamics simulations to compute the muscle forces and joint reactions in the shoulder and L4-L5 joint. This was the first musculoskeletal simulation study of seated double poling. The results showed that the KH position was favorable for higher performance and decreased values of the shoulder joint reactions for female able-bodied athletes with full trunk control. The KL position was favorable for lower L4-L5 joint reactions and might therefore reduce the risk of lower back injuries. These results indicate that it is hard to optimize both performance and safety in the same sit-ski.

Musculoskeletal Demands in Violin and Viola Playing: A Literature Review.

BACKGROUND/AIMS: Research in music medicine has reported incidence rates of musculoskeletal disorders of approx. 70% in instrumental musicians. String players have the highest risk, with rates of performance-related musculoskeletal disorders (PRMDs) of 65% to 88%. Playing the violin or viola requires complex neuromusculoskeletal skills, and the high frequency of repetitive movements, dynamic and static muscle load, awkward postures, poor technique, and practice time are factors causing musculoskeletal strain. In ergonomic terms, these disorders can be categorized based on extrinsic and intrinsic loads. Identification of intrinsic loads, such as muscle utilization and joint motion, is necessary to understand factors influencing musculoskeletal disorders associated with violin playing. The aim of this study was to review the literature on musculoskeletal demands in violin and viola playing. METHODS: A literature search was conducted in the PubMed, COCHRANE, and CINAHL electronic databases from 1999 to 2015 using the search terms violin, viola, high strings, movement, posture, and synonyms. A manual search of Medical Problems of Performing Artists was also conducted. Additional references were identified by searching the citations and reference lists of all identified relevant studies. RESULTS: The results suggest that an asymmetric playing posture, the associated muscle activity, and joint mobility may contribute to musculoskeletal problems in violin and viola players. Evidence suggests an increased load of intrinsic factors in violin/viola performance. CONCLUSION: The identification of intrinsic loads in violin and viola playing may facilitate the development of prevention strategies and interventions.