The rotator cuff is composed of four individual muscles known as the subscapularis, supraspinatus, infraspinatus and teres minor. These muscles completely encapsulate the shoulder over an area of nearly 360 degrees. These muscles function to move the shoulder and deliver strength. These muscles are especially important for the performance of many sports, They are however, also necessary for the adequate performance of many routine activities of living such as reaching overhead or lifting or carrying items.
Rotator cuff injury is a common shoulder problem. The rotator cuff may become injured or torn as a result of an acute injury or may also become damaged from repetitive overuse or aging. Symptoms of rotator cuff injury or tearing include shoulder pain and weakness. A rotator cuff tear can be diagnosed by MRI.