Teres Major

Origin, Insertion, Action, Innervation

Origin: Inferior angle and lower one-third of the lateral (axillary) border of the scapula
Insertion: Medial lip of the bicipital (intertubercular) groove of the humerus (same region as latissimus dorsi)
Action:
Primary: Medial (internal) rotation of the shoulder
Adduction of the shoulder
Extension of the shoulder
Innervation: Lower subscapular nerve (C5–C7)

Palpation Guide

Client position: Prone or seated.
Landmark sequence:

Locate the inferior angle of the scapula — the most inferior point of the scapula.
Teres major originates from the inferior angle and the lower third of the lateral border. It runs laterally and superiorly to the humerus.
From the inferior angle, trace the muscle laterally toward the posterior axillary fold. Teres major forms the inferior border of the posterior axillary fold (latissimus dorsi wraps around it).
Distinguish from teres minor above — teres minor lies along the upper two-thirds of the lateral border, while teres major is at the lower one-third and the inferior angle.

Tissue feel: Thicker and more substantial than teres minor. It forms a palpable cord running from the inferior scapular angle to the posterior axillary fold. In the axillary fold, it feels like a thick, rounded mass.
Confirmation test: Ask the client to medially rotate and adduct the arm against resistance. The teres major contracts, and you can feel it in the posterior axillary fold. Alternatively, resist extension from a flexed position.
Common errors:
Confusing teres major with teres minor — teres major is inferior and a medial rotator; teres minor is superior and a lateral rotator. Resisted medial rotation (major) vs. lateral rotation (minor) distinguishes them.
Confusing teres major with latissimus dorsi — the two share similar insertions and actions. In the posterior axillary fold, latissimus dorsi wraps around teres major. Latissimus is more superficial and has a far broader origin (thoracolumbar fascia, pelvis).
Missing teres major deep to the latissimus dorsi in the axillary fold — the two are layered here and must be differentiated.

Trigger Point Referral

Common TrP locations: The primary TrP is in the mid-belly at the posterior axillary fold, where the muscle crosses from the inferior scapular angle toward the humerus.
Referral pattern: Refers to the posterior deltoid area and the posterior shoulder. May refer down the posterior arm as far as the dorsal forearm.
Clinical significance: The posterior shoulder referral is frequently attributed to the infraspinatus or posterior deltoid. If those muscles have been treated without resolution, check teres major — its TrPs in the posterior axillary fold are commonly overlooked because students focus on the scapula rather than the axillary fold.

Trigger point referral diagram — coming soon

Image coming soon. For visual reference, see [Teres Major at TriggerPoints.net](http://www.triggerpoints.net/muscle/teres-major).

Clinical Notes

Innervation significance:

Shares the lower subscapular nerve (C5–C7) with the subscapularis. The two muscles are synergists for medial rotation and are often hypertonic together. Treating one without the other leaves the rotation pattern incomplete.

Common conditions:

Contributes to conditions/frozen-shoulder by restricting lateral rotation and abduction alongside the subscapularis.
Involved in posterior shoulder pain presentations, particularly after reaching overhead or performing pulling motions.
Teres major hypertonicity contributes to medially rotated shoulder posture alongside latissimus dorsi, pectoralis major, and subscapularis.

What you'll typically find:

Teres major is commonly hypertonic in clients who perform repetitive pulling movements (rowing, swimming, climbing) and in clients with chronically internally rotated shoulders. It is often overshadowed by the more symptomatic infraspinatus and subscapularis in clinical assessments.
The posterior axillary fold is tender to palpation in most clients with shoulder dysfunction. Grasping the fold between thumb and fingers and compressing along the fold will reveal TrPs.

Treatment effects:

Grasp the posterior axillary fold between the thumb and fingers (pincer technique) and apply sustained compression to TrPs. Hold for 30–60 seconds.
Longitudinal stripping from the inferior scapular angle toward the posterior axillary fold is effective.
Post-treatment, abduction and lateral rotation ROM typically improve alongside treatment of the subscapularis and infraspinatus.

Cautions:

The circumflex scapular artery passes through the triangular space (bordered by teres minor superiorly, teres major inferiorly, and long head of triceps laterally). Avoid prolonged deep pressure in this space.
The thoracodorsal nerve (to latissimus dorsi) and thoracodorsal artery run along the lateral border of the scapula near teres major. Be aware of these structures during treatment.
The axillary space is immediately anterior — do not press deeply into the axilla.

Clinical pearl:

Teres major and latissimus dorsi are virtually interchangeable functionally — they share the same actions and insert in the same area. If one is hypertonic, the other almost always is too. Treat both when addressing internal rotation restriction. Grasp the posterior axillary fold and you capture both muscles in one technique.

Assessment

Manual muscle testing:

Medial rotation and adduction: Client prone with arm off the table. Ask the client to adduct and medially rotate against resistance. This tests teres major along with latissimus dorsi and subscapularis.

Stretch test:

Shoulder flexion with lateral rotation: Client supine. Flex the arm overhead with the arm in lateral rotation. Restriction suggests teres major (and latissimus) shortening.

Related special orthopedic tests:

Lateral rotation range — restricted lateral rotation implicates medial rotator tightness (subscapularis, teres major, pectoralis major, latissimus dorsi)

Muscle Groups

Medial (internal) rotators of the shoulder (functional):

anatomy/muscles/subscapularis
Teres major (this article)
anatomy/muscles/pectoralis-major
Latissimus dorsi

Shoulder adductors (functional):

Teres major (this article)
anatomy/muscles/pectoralis-major
Latissimus dorsi

Shoulder extensors (functional):

Teres major (this article)
Latissimus dorsi
anatomy/muscles/deltoid — posterior fibers

Subscapular nerve group (innervation):

anatomy/muscles/subscapularis — upper and lower subscapular nerves
Teres major (this article) — lower subscapular nerve

Related Muscles

Synergists for medial rotation:

anatomy/muscles/subscapularis — shares the lower subscapular nerve; the two are treated as a pair
Latissimus dorsi — shares the same insertion and actions; the two function as a unit

Antagonists:

anatomy/muscles/infraspinatus — primary lateral rotator
anatomy/muscles/teres-minor — lateral rotator lying immediately superior to teres major on the lateral scapular border

Same innervation (lower subscapular nerve):

anatomy/muscles/subscapularis — shares C5–C7 lower subscapular nerve

Key Takeaways

Functions as "little latissimus" — shares the same insertion, actions, and clinical behavior; treat the two together.
Adjacent to teres minor but opposite in rotational action — minor rotates laterally, major rotates medially.
Posterior axillary fold TrPs are commonly overlooked when infraspinatus and subscapularis have been treated without resolving posterior shoulder pain.