This little muscle is located between your collarbone (clavicle) and the first rib near the sternum (breastbone).
When it gets tight, it can literally pull the collarbone down toward the first rib - squishing the two bones together and possibly entrapping nerves in between. Ouch!
Despite its importance, Subclavius is not well known and rarely touched or worked on by massage therapists.
How does it get injured?
Treatment of the Subclavius
Massage therapy and strength-conditioning are the two most effective therapies for this muscle.
When injured, it's best to keep this area stabilized and avoid stretching, i.e. raising the arms high or out to the sides.
When tight, stretching is OK, although it's not easy to actually stretch the Subclavius.
Typically, an epicenter of tension, and pain, resides directly in mid-muscle and near the sternal attachment. Ask your massage therapist to locate these spots and compress them firmly for 15-20 seconds to release potential trigger points and encourage blood flow.
Trigger points are often felt down the arm and into the thumb and the first two fingers, as in the image. This is due to the impingement of the brachial plexus nerves. Releasing those trigger points with steady pressure will relax the Subclavius.
Strengthening the Subclavius and other shoulder muscles (Deltoids, rotator cuff muscles) will speed up recovery and prevent another injury from re-occuring long-term.