A rotator cuff is a group of four muscles and tendons that cover the head of the humerus. The function of the rotator cuff is to stabilize the shoulder joint and help you lift your arms and rotate them.
A rotator cuff tear is common in sports like volleyball, swimming or tennis, or in jobs like painting or cleaning windows. It is usually caused by normal wear and tear, or repetitive motion of the arm. But it also can happen if you fall on your arm or lift something heavy with a jerking motion.
The main symptoms of rotator cuff tear are trouble raising the arm, or pain when moving the arm or lying on it. Weakness in the shoulder and inability to lift things may also be signs of a rotator cuff tear.
The first thing to do if you have any of these signs is to see your doctor. If a torn rotator cuff is not treated early enough, it may lead to more serious problems over time, including frozen shoulder and arthritis.