A rotator cuff tear can occur suddenly. It may happen by falling onto an outstretched arm or lifting something heavy.
A rotator cuff tear can also develop slowly over time. Repetitive shoulder motions during sports and physical activity are often contributing factors. A rotator cuff tear is common among athletes in sports like baseball, tennis, and weightlifting.
Additionally, degenerative changes to the shoulder may increase the likelihood of a rotator cuff tear. In this instance, bone spurs that develop on the underside of the acromion rub against the rotator cuff.