Muscle Monday 4: Rotator Cuff pt. 1: Supraspinatus

The first muscle in our rotator cuff series is the supraspinatus. It is named for its location: “supra” meaning “above” and “spinatus” meaning the spine - it is located above the spine of the scapula (the bony ridge you see on the scapula above the text on the photo).

This muscle works together with the deltoid to initiate abduction of the shoulder - which means raising your arm out to the side and up to your head, like when you do jumping jacks. It does this for the first 10-15 degrees of the movement, after which the deltoid takes over and it moves into more of an assistance role. It also helps stabilize the head of the humerus (upper arm bone) inside the shoulder girdle.

First I’ll explain a little about the shoulder itself. The shoulder is a ball-and-socket joint, like the hip, although the “ball” (the head of the humerus) is much larger than the “socket” (the glenoid fossa). This makes for an extremely mobile joint, but at the sacrifice of its stability. That’s why the supraspinatus is actually the most important of the four rotator cuff muscles due to its role in stabilizing the joint. Check out the below photo to see an illustration of this - highlighted in green are the glenoid fossa on the scapula and the head of the humerus. (The anatomical name for the shoulder is the glenohumeral joint).

The tendon (the part that attaches the muscle to the bone) doesn’t receive a lot of blood supply which causes it to heal more slowly. An unfortunate set of circumstances considering it’s the most susceptible to tearing. Its position as it passes beneath the acromion (the bony arc that makes the top point of your shoulder) makes it susceptible to impingement when the arms are raised. As a result, tendinitis is quite common here (inflammation of the tendon).

Luckily, tendinitis is something that massage can be very helpful for by breaking down scar tissue with frictioning movements, then realigning the fibers through stretching.

If overhead movements are painful or uncomfortable for you, it could be an issue with your supraspinatus. Book an appointment for an assessment and massage treatment and hopefully we can get you throwing that football or overhead pressing that barbell again quickly.