Subscapularis anatomy and function
The subscapularis is a muscle which sits between the ribs and the shoulder blade (scapula) — its name means “beneath the scapula”. One end covers the whole of the inside edge of the shoulder blade, and the other end narrows to a tendon which attaches to the inner part of the humerus (upper arm bone) and the shoulder joint capsule. Its role is not to produce movement, but instead to stop the head of the humerus (the ball) from moving too far up and out of the glenoid (the socket) when you raise your arm. In other words, it is a stability muscle which has an important role in preventing dislocation of the shoulder, and compression of the subacromial space.
Subscapularis is one of the four muscles that make up the rotator cuff, but it gets torn far less frequently than the more vulnerable supraspinatus and infraspinatus. This may be why it’s often ignored by therapists when treating sore necks and shoulders, but in my view that’s a mistake. Good subscapularis function is essential to good neck and shoulder function, and I have a few theories as to why this is the case.
How does subscapularis affect the neck, shoulder and ribcage?
One theory is the effect that subscapularis has on the ribs. As I’ve mentioned, subscapularis sits between the ribs and the shoulder blade. Normal shoulder movement depends on the shoulder blade being able to glide freely over the ribs. When muscles are sore, they tend to tighten up; and this can affect the surrounding muscles – especially serratus anterior, which attaches directly to the ribs, causing the ribcage to stiffen up.
In other words, a sore subscapularis may lead to dysfunctional movement of the shoulder blade over the ribs. This in turn can place excessive strain on the rib and shoulder joints, leading to pain in the upper back, neck and/or shoulder.
I suspect that another problem with subscapularis tension is the effect it can have on blood flow and nerves. I have a theory that that when a muscle is tight, the constriction affects not only the muscle fibres, but also other local structures such as blood vessels and nerves. In the case of subscapularis, this could - hypothetically — affect the axillary (armpit) artery, plus the nearby axillary lymph nodes and the ulnar branch of the brachial plexus — the nerve that goes down to the inside of the elbow and the ring and little fingers. It’s certainly noticeable that patients often comment that they feel odd sensations in these areas, as I release their tight subscapularis; or that once I’ve finished, they feel a rush of heat to the area, which may be a sign of increased blood flow.
How can you release the subscapularis?
Restoring normal tone to the subscapularis and serratus anterior is not easy on your own. I often use my heels to release my patients’ subscapularis — most therapists use their fists or fingers, but can be tricky to do that without jabbing your patient and causing more discomfort than necessary. If I have to release your subscapularis and serratus anterior with my heel, I’ll ask you to lie on your back with your hand behind your head. This brings the edge of your scapula out to the side of your body, and I can then fit my heel between the edge of your scapula and your ribs, and use my bodyweight to stretch and massage the subscapularis and serratus, gently and rhythmically until the spasm subsides.
Not only does this tend to reduce the tone in the subscapularis and serratus anterior and to allow the ribcage and shoulder blade to move more smoothly, it also frequently helps to decrease neck pain and increase neck rotation, which is a great knock-on effect.
After I’ve released your subscapularis, I’ll show you how to stretch it yourself, using a chair, Swiss ball or yoga brick, so that you can maintain the improvement at home – and then teach you exercises to restore muscle balance around the shoulder, so that the subscapularis doesn’t get sore and set the whole cycle off again!
Is your subscapularis causing problems?
If you think a tight subscapularis might be affecting your neck, shoulder or ribcage, please contact my team on 0207 175 0150 and book an appointment. Finding the true underlying cause of your issue is the key to getting a great long-term outcome.
See my page on shoulder pain treatment.