Muscle of the Month – February 2020


One of the most amazing joints in the body is the shoulder – it is a highly mobile joint with a lot of range of motion, and allows us to do many of the tasks we perform each day, in and out of the gym. To keep your shoulder joint stable throughout all of this activity, we have 17 (read that again – 17!) muscles that connect to our shoulder blades. Of these 17, four are called the rotator cuff muscles, and keep the scapula (shoulder blade) pulled into the humerus (arm bone). This month (and the next three) we are going to talk about these muscles. Why you ask? Well as many of you can attest, the shoulder is one of the most commonly injured parts of the body, and the first step of rehabbing, or better yet, preventing injuries is to understand what each muscle is meant to do. First up, the supraspinatus.

Well really first up is some basic terminology. Well really just one term:

Humerus. Not to be confused with humorous. The humerus is the bone of the upper arm and contains the ball that comprises the ball and socket joint of the shoulder. Now, the supraspinatus.

The supraspinatus is a relatively small muscle that starts in the upper back on the shoulder blade, and goes under the acromion (the bone on top of our shoulders) to connect to the humerus in the front of the shoulder. Like all of the rotator cuff muscles, the supraspinatus holds your humerus in place and keeps your upper arm stable. Think of it like a seatbelt that helps to pull your shoulder back and keep the socket in place.

It’s primary function is to initiate abduction (lifting) of the arm laterally from the body (raise your arm up to the side). The supraspinatus assists the deltoids in this motion, so it is not the only muscle responsible for abduction, but it is the main rotator cuff muscle that does so (others do support it, but you’ll have to wait for that). To target the supraspinatus you will need to perform abduction exercises, but use lighter weight so that the larger deltoid muscles do not take over. Lateral dumbbell raises, banded or dumbbell external rotation, or any of the variations of these exercises will work the supraspinatus.