Rotator cuff syndrome refers to muscle damage caused by repetitive motion, muscular imbalances, or trauma to one or more of the four muscles in the rotator cuff – Supraspinatus, Infraspinatus, Subscapularis, and Teres Minor. Rotator cuff syndrome is characterized by shoulder pain, especially on abduction (raising the arms away from the body) through a painful arc.
The rotator cuff attaches from the scapular (shoulder blade) to the humerus (arm bone) and functions to pull the arm into the shoulder socket, stabilizing the arm, so that overhead and rotational movements can be performed. The shoulder is the most mobile joint in the body and to achieve that mobility, the shoulder has fewer ligamentous attachments, which means less stability, relative to other joints in the body. The shoulder is primarily stabilized by the rotator cuff muscles. Therefore, if any part of the rotator cuff weakens, the less able it will be to pull the arm firmly into the shoulder socket. This instability leads to further dysfunction and pain or restricted movement.