The rotator cuff is a series of four muscles that run from the scapula (shoulder blade) around the shoulder glenoid (socket) and attach to the humeral head (ball of the shoulder) by their tendons. The muscles of the rotator cuff work to keep the humeral head centered in the glenoid (socket) as the arm moves. Injury or degeneration (wear and tear) can result in a tear of the rotator cuff tendon. Rotator cuff tears affect the ability to keep the humeral head (ball of the shoulder) centered on the glenoid (socket), subsequently causing weakness and pain. Untreated rotator cuff tears retract, get larger, the muscle atrophies (turns into scar tissue and fat) with disuse, and can eventually become irreparable.
Front view of rotator cuff muscles
Back view of deep rotator cuff muscles
Frequent Signs and Symptoms
- Pain along the upper arm between the shoulder and elbow
- Pain that is increased when reaching out and overhead, or when lifting objects
- Aching pain at rest or at night while trying to sleep
- Loss of strength
- Limited motion of the shoulder, especially reaching overhead
- Crepitation (a crackling sound) when moving the shoulder