Rotator Cuff Anatomy
The rotator cuff is comprised of four muscles and their tendons which insert at the top of the humerus or arm bone. The rotator cuff function along with the deltoid to elevate and rotate the arm. The four muscles of the rotator cuff are complex and are critical in allowing for the shoulder’s incredible range of motion; more than any other joint in the body.
The most frequently injured of the rotator cuff tendons is the supraspinatus. The supraspinatus tendon sits on the top of the shoulder and exits the supraspinatus fossa as it turns into tendon going underneath the coracoacromial arch.
This tendon is subject to significant forces of compression as the shoulder does pass under the coracoacromial ligament and that compression can lead to inflammation. Inflammation can lead to weakness, weakness can lead to rotator cuff tears, and all of these can cause significant shoulder pain.