The biceps muscle has two tendons at the shoulder. The long head inserts at the top of the socket and the short head inserts adjacent to the socket on the coracoid process of the scapula. Tendonitis occurs most commonly in the long head of the biceps tendon. A debate persists regarding the role of the long head of the biceps in the function of the shoulder. Inflammation is caused by micro tears in the tendon generated by overuse or exceeding the strength of the tendon. Repetitive motion such as throwing, serving, or swinging a golf club can predispose to these micro tears and inflammation.