A rotator cuff tear is a tear of one or more of the tendons of the four rotator cuff muscles. A rotator cuff injury can include any type of irritation or damage to the rotator cuff muscles or tendons.
There are two main causes of rotator cuff tears: injury & degeneration. You can tear your rotator cuff if you fall down on your outstretched arm or lift something too heavy with a jerking motion. Or this type of tear can occur with other shoulder injuries, such as broken collarbone or dislocated shoulder.