Teres Major: Pain Pattern and Treatment
The teres major runs from the lower tip of the shoulder blade to the front of the upper arm bone. It pulls the arm down, back, and inward, alongside the latissimus dorsi. Its documented pattern is a deep ache over the back of the shoulder and down the back of the upper arm. Reaching up and forward is the movement that finds it.
Attachments and action
Origin: The back of the inferior angle of the scapula and the lower third of its lateral border.
Insertion: The medial lip of the intertubercular groove of the humerus, alongside the latissimus dorsi tendon.
Action: Adduction, extension, and medial rotation of the arm; it works with the latissimus dorsi in pulling and in bringing the raised arm down.
Where the pain is felt: Deep in the back of the shoulder, over the rear of the shoulder cap. Down the back of the upper arm along the triceps. Sometimes the back of the forearm.
Common causes: Pull-ups, rows, and lat pulldowns; tennis serves and pitching; rowing and swimming; chopping wood; wrestling a heavy steering wheel; resting the elbows on a desk for hours.
Patients say: “It is deep in the back of my shoulder, not on top.” Sharp pain leaning on the elbows. “I can reach up, but not up and forward.” A tight cord in the back of the armpit.
When to get evaluated: Back-of-shoulder pain with arm weakness after a fall, or with numbness that follows the whole arm, needs medical evaluation before anything else.
How this muscle is examined and treated
Examination tests reaching up and forward against the latissimus and teres major together, then isolates the teres major by pinching the back wall of the armpit and pressing the muscle over the lower blade. Needling here addresses the muscle at the back of the armpit and over the lower blade. Assessment and treatment happen in the same visit.
Related conditions
Shoulder DysfunctionSports & Performance InjuriesChronic 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