The capsular pattern of the GH joint is external rotation, abduction, and internal rotation. The coracoacromial arch forms the roof of the glenohumeral joint and is composed of the acromion, the coracoid process, and the cora- coacromial ligament. The space between the arch and the humeral head contains the subac- romial bursa, the rotator cuff tendons, and the long head of the biceps. Impingement of the structures in the subacromial space is a com- mon source of shoulder pain and is often related to impaired biomechanics of the shoulder girdle complex.