Your rotator cuff is made up of the muscles and tendons in your shoulder. These muscles and tendons connect your upper arm bone with your shoulder blade. They also help hold the ball of your upper arm bone firmly in your shoulder socket. The combination results in the greatest range of motion of any joint in your body.

A rotator cuff injury includes any type of irritation or damage to your rotator cuff muscles or tendons. Causes of a rotator cuff injury may include falling, lifting and repetitive arm activities — especially those done overhead, such as throwing a baseball or placing items on overhead shelves.

About half of the time, a rotator cuff injury can heal with self-care measures or exercise therapy.

Rotator cuff injury signs and symptoms may include:

• Pain and tenderness in your shoulder, especially when reaching overhead, reaching behind your back, lifting, pulling or sleeping on the affected side
• Shoulder weakness
• Loss of shoulder range of motion
• Inclination to keep your shoulder inactive

The most common symptom is pain. You may experience it when you reach up to comb your hair, bend your arm back to put on a jacket or carry something heavy. Lying on the affected shoulder also can be painful. If you have a severe injury, such as a large tear, you may experience continuous pain and muscle weakness.