When a rotator cuff muscle is torn, it is typically because of one of two processes. The first is something called an acute tear, which means that there’s been some trauma to the shoulder. Whether this is involved in falling on your shoulder or you’re lifting something heavy and feel a pop, this is a tendon that was attached to the bone or muscle that was attached to the bone and has been ripped off because of some traumatic event. The other type of tear is something called a degenerative tear, and this is one that develops over time because of overuse. Typically, this is because of using your arms over your head a lot or something that is just kind of worn down over the years and eventually leads to a full tear in the shoulder.