Rotator cuff muscles are responsible for the stability and function of the shoulder joint. The rotator cuff tendon attaches these four muscles to the humerus. This tendon can tear form its insertion site either from a single traumatic force or by continuous trauma of rubbing against the acromion bone (long term impingement). The most commonly injured tendon is the supraspinatous tendon. Symptoms of rotator cuff tear include pain in front or outside portion of the shoulder, radiating pain down to mid arm area, weakness and loss of strength in the affected arm, and night pain. Diagnosis is confirmed by a good quality MRI.

Treatment is initially aimed at reducing inflammation and restoring motion and strength similar to impingement syndrome. It is unlikely for a torn rotator cuff to heal itself, and it may even propagate and become larger. In younger individuals and heavy laborers, these tears are best treated by surgical fixation.