Shoulder Tendonitis

Shoulder tendonitis is an inflammation of the rotator cuff tendon or the biceps (bicipital) tendon. Often both tendons are affected.

Rotator Cuff Tendonitis

The rotator cuff is composed of four tendons that surround the humeral head (ball). In addition to moving the shoulder joint, the rotator cuff compresses the ball into the socket. This compression helps stabilize the shoulder joint, providing the shoulder with the widest range of motion of any joint in the body.
The most common tendon involved in tendonitis (and rotator cuff tears) is the supraspinatus tendon. This tendon is positioned between the humeral head and the acromion bone which provides a roof above the ball and socket joint.

By the time we reach age 40, rotator cuff symptoms become very common because the Supraspinatus tendon is both mechanically and biologically disadvantaged. The Supraspinatus Tendon is the most important & highly stressed portion of the rotator cuff. It also has a poor blood supply which reduces its ability to heal itself. The Rotator Cuff is constantly in use - stabilizing the shoulder whenever our hand moves. This constant contraction tends to wring-out the microscopic blood vessels within the tendon - further compromising the nutrition and healing ability of the rotator cuff. As a result, the rotator cuff tendons age prematurely - resulting in Tendonitis

The body tries to repair these, but the process is slow. The result for some of us is a prolonged cycle of inflammation and repair and is responsible for the aching and pain, which may take months or even years to settle down as the repair process is gradually completed.

Shoulder Bursitis can commonly occur in combination with rotator cuff tendonitis.