Structure of the Rotator Cuff

The rotator cuff consists of four muscles and tendons that extend into the shoulder area and keep the ball of the upper arm in the shoulder socket. According to Mayoclinic.com, the rotator cuff muscles and tendons allow the shoulder to have more range of motion than any other joint in the body.

Significance

• The rotator cuff is a highly complex configuration of muscles and tendons that are involved in about every movement of the upper body. As a result, the rotator cuff is often overused during sports, weightlifting and even work-related tasks, rendering it vulnerable to injuries.

Posterior Rotator Cuff

• The two muscles and tendons that make up the posterior or rear part of the rotator cuff are called the infraspinatus and teres minor. The infraspinatus and the teres minor move the shoulder away from the body.

Superior Rotator Cuff

• The supraspinatus is located on top of the shoulder and is known as the superior rotator cuff. It is the tendon that is most commonly injured.

Anterior Rotator Cuff

• The subscapularis makes up the anterior part of the rotator cuff. It is responsible for the internal rotation of the humerus or arm bone, according to Sports-injury-info.com.

Types of Injuries

• When rotator cuff tendons become inflamed from overuse, they have trouble passing between the top of the humerus and acromion bone in the shoulder. This can cause tendinitis or a shoulder impingement, where the bones pinch the tendons. Consequently, the rotator cuff can sometimes tear.