The rotator cuff is a group of muscles and tendons that helps your shoulder move and stay stable. (Tendons are thick cords of tissue that connect muscle to bones. Tissue is the material that helps support your body.)
Rotator cuff injuries, or tears, are common. They usually happen from repeated overhead motions in jobs like painting or carpentry or sports like baseball or tennis. Sometimes falling on your hand or another injury can injure the rotator cuff. Rotator cuff injuries are more likely as you get older, because the tendons get worn down.
Some rotator cuff tears are not painful. Others are very painful.