The rotator cuff muscles are comprised of four muscles that function as a stabilizer of the shoulder joint and are responsible for movement of the arm. Rotator cuff injuries occur at the point where the tendon of the muscle attaches to head of the humerus.
The most common muscle involved in a rotator cuff injury is the supraspinatus muscle and sometimes the result of a sports injury.
The tendon of the supraspinatus muscle when injured can result in a tear and that can be either partial or complete.
Pain and sometimes weakness is noticed when this type of shoulder injury occurs and is noticed with certain movements and position of the arm.