Shoulder impingement syndrome occurs as the result of chronic, repeated compression of the rotator cuff tendons. This impingement causes pain and movement problems. An injury to the shoulder also can cause this condition. People who do repeated overhead arm movements are most at risk for developing a shoulder impingement. Poor posture also can contribute to its development. If left untreated, shoulder impingement can lead to more serious conditions, such as a rotator cuff tear. Physical therapists help decrease pain and improve shoulder motion and strength in people with shoulder impingement syndrome.