The Rotator Cuff is a group of muscles that work in the shoulder joint to keep the humerus from popping out. This makes the Rotator Cuff critical for shoulder stability.

There are four muscles in the Rotator Cuff: the Teres Minor, the Infraspinatus, the Supraspinatus and the Subscapularis (not pictured - it lies on the front aspect of the scapula)

These muscles all work together to keep tension on the humerus, locking it into the shoulder joint.

The Rotator Cuff is one of the primary areas of shoulder trauma; when someone has a shoulder injury, chances are very good that is related to injury in the Rotator Cuff.

This trauma can be due to sudden injury or can be from overuse in undesirable movement patterns. The upright row exercise is a prime example of this undesirable movement pattern.

The main functions of the Rotator Cuff are shoulder joint stabilization and external rotation of the humerus (rotating the arm to the rear).

Exercises that work the Rotator Cuff include: