Subclavius: Pain Pattern and Treatment
The subclavius is a small muscle tucked under the collarbone, running from the first rib to the underside of the clavicle. It steadies the collarbone and cushions the vessels and nerves passing beneath it. Its documented pattern is long for so small a muscle: pain at the front of the shoulder over the collarbone, down the front of the upper arm, and along the thumb side of the forearm to the thumb, index, and middle fingers, with the elbow and wrist skipped. It looks like a pinched nerve, and it sits over the thoracic outlet, so the page names that. This is a sub-page of the pectoralis major page.
Attachments and action
Origin: The first rib and its cartilage, at the junction.
Insertion: The groove on the underside of the middle third of the clavicle.
Action: Depression and stabilization of the clavicle; it steadies the collarbone during arm movement and protects the vessels beneath it.
Where the pain is felt: At the front of the shoulder over the collarbone. Down the front of the upper arm. Along the thumb side of the forearm. In the thumb, index, and middle fingers, palm and back. The elbow and the wrist are skipped.
Common causes: A heavy backpack or a bag strap on the collarbone; a seat belt in a collision; overhead work; push-ups and bench press; carrying a child on the shoulder; a fall on the point of the shoulder; a collarbone fracture in the past.
Patients say: "Pain from my collarbone to my thumb, but my elbow is fine." "They tested for a pinched nerve and found nothing." An ache along the thumb side of my forearm. "The backpack strap sets it off."
When to get evaluated: Arm pain with chest pressure, sweating, or shortness of breath needs cardiac evaluation before anything else. Collarbone pain after a fall or a crash needs an X-ray first. Arm swelling, a hand that turns pale or blue with the arm raised, or numbness with weakness needs a vascular and nerve assessment for thoracic outlet syndrome.
How this muscle is examined and treated
Examination raises the arm to test the outlet, then presses under the middle of the collarbone for the point that reproduces the line of pain down the arm to the thumb, and tests the pulse and the hand for signs of the outlet. Needling here addresses the small muscle under the collarbone, at a shallow angle along the bone, with the vessels beneath respected. Assessment and treatment happen in the same visit.
Related conditions
Shoulder DysfunctionNeck & Cervical PainChronic Pain Patterns
This page is educational. It describes muscle referral patterns commonly associated with pain; it does not diagnose your condition. Individual patterns vary. For evaluation of your specific pain, see a licensed clinician. Seek immediate medical care for emergencies. Eugene Baek, L.Ac. · New Jersey License 25MZ00080600