Posterosuperior and anterosuperior impingement in overhead athletes

Abstract

Repetitive throwing places the shoulder in extreme positions and imparts tremendous stress on both the static and dynamic stabilizers of the shoulder. Over time, soft tissue and bone changes occur as a means of adaptin to these high stresses. While these adaptations may initially be beneficial and improve performance, they may eventually lead to a broad spectrum of shoulder pathologies known as internal impingement, which is a major cause of shoulder pain in throwing athletes. Internal impingement may be subclassified into the more common posterosuperior impingement and the far less common anterosuperior impingement. Posterosuperior impingement refers to impingement of the posterosuperior rotator cuff between the greater tuberosity and posterosuperior aspect of the labrum, while anterosuperior impingement involves impingement of the subscapularis tendon between the anterior humeral head and anterior glenoid rim. Nonoperative treatment comprises the first line of management for this syndrome, as the majority of patients with internal impingement will be successfully treated without surgery. Modalities focus on increasing shoulder range of motion, improving scapular function, and address-parting all concomitant pathology such as lower back, core, and lower extremity disorders. Surgical treatment should be considered if extensive conservative therapy has failed to improve symptoms or if there is suspicion of significant mechanical dysfunction.