The rotator cuff is a group of muscles and tendons that attach to the bones of the shoulder joint, allowing the shoulder to move and keeping it stable.
- Rotator cuff tendinitis refers to irritation of these tendons and inflammation of the bursa (a normally smooth layer) lining these tendons.
- A rotator cuff tear occurs when one of the tendons is torn from the bone from overuse or injury.
Swimmer's shoulder; Pitcher's shoulder; Shoulder impingement syndrome; Tennis shoulder; Tendinitis - rotator cuff; Rotator cuff tendinitis; Shoulder overuse syndrome
The shoulder joint is a ball and socket type joint. The top part of the arm bone (humerus) forms a joint with the shoulder blade (scapula). The rotator cuff holds the head of the humerus into the scapula. It also controls movement of the shoulder joint.
The tendons of the rotator cuff pass underneath a bony area on their way to attaching the top part of the arm bone. When these tendons become inflamed, they can become frayed over this area during shoulder movements. Sometimes, a bone spur narrows the space even more.
Rotator cuff tendinitis is also called impingement syndrome. Causes of this condition include:
- Keeping the arm in the same position for long periods, such as doing computer work or hairstyling
- Sleeping on the same arm each night
- Playing sports requiring the arm to be moved overhead repeatedly such as in tennis, baseball (particularly pitching), swimming, and lifting weights overhead
- Working with the arm overhead for many hours or days, such as in painting and carpentry
- Poor posture over many years
- Rotator cuff tears
Rotator cuff tears may occur in two ways:
- A sudden acute tear may happen when you fall on your arm while it is stretched out. Or it can occur after a sudden, jerking motion when you try to lift something heavy.
- A chronic tear of the rotator cuff tendon occurs slowly over time. It is more likely when you have chronic tendinitis or impingement syndrome. At some point, the tendon wears down and tears.
There are two types of rotator cuff tears:
- A partial tear occurs when a tear does not completely sever the attachments to the bone.
- A complete, full thickness tear means that the tear goes all the way through the tendon. It may be as small as a pinpoint, or the tear may involve the entire tendon. With complete tears, the tendon has come off (detached) from where it was attached to the bone. This kind of tear does not heal on its own.