A rotator cuff tear is a common injury, especially in sports like baseball or tennis, or in jobs like painting or cleaning windows. It usually happens over time from normal wear and tear, or if you repeat the same arm motion over and over. But it also can happen suddenly if you fall on your arm or lift something heavy.
Your rotator cuff is a group of four muscles and tendons that stabilize your shoulder joint and let you lift and rotate your arms.
There are two kinds of rotator cuff tears. A partial tear is when the tendon that protects the top of your shoulder is frayed or damaged. The other is a complete tear. That’s one that goes all the way through the tendon or pulls the tendon off the bone.