The rotator cuff is a group of four muscles and their tendons that surround the shoulder joint, providing stability and movement. These muscles help in lifting, rotating, and controlling arm movements. Rotator cuff injuries are common, especially in athletes, manual laborers, and older adults, and can occur due to overuse, aging, trauma, or degenerative changes. Common conditions include rotator cuff tears, tendinitis, and bursitis, which can cause shoulder pain, weakness, and restricted range of motion. Treatment varies based on severity and includes rest, physical therapy, anti-inflammatory medications, corticosteroid injections, and in severe cases, surgical repair.