Throwing injuries of the upper extremity

Throwing Injury Prevention Strategies with a Whole Kinetic Chain-Focused Approach

Purpose of Review

This review examines the relationship between the baseball pitching motion and the kinetic chain. The goal was to determine the underlying causes of a deficiency in throwing mechanics throughout a throwing motion, and to provide an evidence-based approach on how to prevent injuries caused by a lack of proper mechanics. In doing so, we sought to provide a warm-up strategy that can be added to every baseball player’s daily on-field routine that is tailored to each phase of the throwing motion.

Recent Findings

To help minimize the risk of injury to overhead throwing athletes, a thorough understanding of the throwing motion is critical. Throwing a ball places extreme stress on the body, notably the shoulder and elbow joints. With a clear understanding of the biomechanics of throwing, we can develop an injury prevention routine to minimize unnecessary stresses throughout the kinetic chain.

Summary

The throwing cycle is a complex motion that places various stresses throughout the thrower’s body, from the ankle to the core, and from the back to the shoulder and elbow. A thorough understanding of the mechanics of this motion, along with specific exercises to target the specific actions of each phase, may allow for throwers, regardless of their age and experience, to minimize injury risk.

Radiographic and MRI Assessment of the Thrower's Elbow

PURPOSE OF REVIEW

Throwing athletes are vulnerable to elbow injuries, especially in the medial elbow, related to high stress and valgus load in both acute and chronic settings as a result of this complex biomechanical action. This current review details the relevant anatomy and imaging features of common elbow pathology identified with radiographs and MRI in throwing athletes.

RECENT FINDINGS

Although elbow pathology in throwing athletes is well documented, advances in imaging technology and technique, particularly with MRI, have allowed for more detailed and accurate imaging description and diagnosis. Pathology of thrower's elbow occurs in predictable patterns and can be reliably identified radiologically. Clinical history and physical examination should guide radiologic evaluation initially with radiographs and followed by an MRI optimized to the clinical question. Constellation of clinical, physical, and radiologic assessments should be used to guide management.

Internal Derangement of the Shoulder Joint in Asymptomatic Professional Baseball Players

RATIONALE AND OBJECTIVES

To evaluate the influence of throwing activity on shoulder morphology and the difference in shoulder morphology on MRI between asymptomatic professional baseball players and volunteers who play baseball as a recreational activity.

MATERIALS AND METHODS

This retrospective case-control study included 68 asymptomatic professional baseball players (32 pitchers, 36 batters) and 30 male volunteers. Morphologic changes in the following shoulder structures were assessed on MRI: rotator cuff, glenoid labrum, humeral head, subacromial-subdeltoid bursa, subcoracoid bursa, long head of the biceps tendon, deltoid muscle, acromion, and clavicle.

RESULTS

Partially torn supraspinatus, posterior glenoid or labral lesions, bone marrow edema, intraosseous cysts of the humeral head, and edematous subacromial-subdeltoid bursa were significantly more commonly observed in players (p = 0.01, p < 0.001, p = 0.03, p< 0.001, and p < 0.001). Players with more than 10 years of experience had a significantly higher incidence of patchy intermediate signal abnormality (odds ratio: 3.73, p = 0.03), partial tear in the supraspinatus tendon (odds ratio: 6.20, p = 0.03), and edematous change in the subacromial-subdeltoid bursa (odds ratio: 2.96, p = 0.03).

CONCLUSION

The results from our study showed that repetitive throwing activities cause macroscopic structural lesions of the shoulder joints in asymptomatic baseball players. Significance of these lesions is to be determined.

Magnetic resonance arthrography results that indicate surgical treatment for partial articular-sided supraspinatus tendon avulsion: a retrospective study in a tertiary center

Background Specific findings on magnetic resonance arthrography (MRA) that indicate the need for surgery in patients with partial articular-sided supraspinatus tendon avulsion (PASTA) are not well understood. Purpose To determine which MRA findings are characteristic of patients who undergo surgery for PASTA. Material and Methods From July 2011 to February 2014, MRA findings for patients treated for PASTA were retrospectively reviewed. The patients were divided into two groups: conservative treatment and surgical repair. MRA findings were compared between the groups. The following MRA results were assessed: length grade, width grade, co-existing superior labrum anterior posterior (SLAP) lesions, degenerative changes in the glenohumeral joint, presence of subacromial-subdeltoid bursitis, acromion type, presence of adhesive capsulitis, and tears of the subscapularis or infraspinatus tendon within the rotator cuff. Logistic regression analyses were conducted to identify which MRA findings were significantly associated with surgical treatment. Results Forty-five surgically treated patients and 203 conservatively treated ones were evaluated. The MRA findings showed significant differences between the groups with respect to length grade, width grade, degenerative changes in glenohumeral joint, bursitis, and co-existing rotator cuff tears ( P < 0.05). Multivariate logistic regression showed correlations between surgical repair and both grade 3 length tears (odds ratio, 30.8) and co-existing tears of the subscapularis or infraspinatus tendon (odds ratio, 2.9). Conclusion Surgical treatment is commonly performed in PASTA patients whose lesion lengths are grade 3 or who have co-existing tears in the subscapularis or infraspinatus tendon. Radiologists should pay attention to these MRA signs when evaluating PASTA patients.