The Quadrangular space is a name termed for the shape of the opening created by the crossing of the Teres Major and Minor muscles, along with the humerus and the long head of the triceps. These four boundaries create a place that allows nerves and blood vessels to traverse from behind the shoulder, to in front of the shoulder just beneath the long bone of the arm, the humorous. In fact, major nerves and blood vessels flow through here.
If there is any impingement, or tightening of this space due to inflammation or injury, it can have effects that range from tingling, to full numbness of the hand or fingers. Two nerves in particular affect numbness in the fingers of the hand.. the ulnar nerve, and the radial nerve. Both of these get their names from the paths they follow along the bones of the arm, the Ulna and the Radial bones of the lower arm.
Keeping Teres Minor and the long head of the triceps muscles in a relaxed and lengthened state can go a long way to helping to reduce pain and numbness in the shoulder and arms.
Sleeping position can also make a big difference since sleeping on the side will tend to reduce the opening size of the quadrangular space causing a pinch on the nerves here. ‘Lifting’ with a pillow under the chest can open this up when you sleep, along with another pillow just above your collar bone creating a ‘valley’ where your shoulder and arm can rest without being pinned down with the force of the weight of your body.
Come by for a visit, and I can illustrate how best to protect this space while you sleep – and also give these muscles a stretch that will lessen the tension around this constricted area.