1 It supports the deltoid and supraspinatus muscles. 2  Inflammation of this bursa is the cause of several shoulder problems. 3  Subscapular â Located between the subscapularis tendon and the scapula. 4  It reduces wear and tear on the tendon during movement at the shoulder joint.ig 1.0 â The articulating surfaces of the shoulder joint. The shoulder joint is formed by the articulation of the head of the humerus with the glenoid cavity (or fossa) of the scapula. This gives rise to the alternate name for the shoulder joint â the glenohumeral joint.