Origin: dorsal surface of inferior angle of the scapula on the lower 1/3 of scapular axillary border;
Insertion: medial lip of bicipital groove of humerus; medial to latissimus dorsi  tendon;
Action: adducts and medially rotates humerus at the shoulder; extends the shoulder joint;
Reversed origin insertion action: when arm is fixed, adducts and elevates inferior angle of scapula;
Nerve supply: lower  subscapular, C5, C6, C7;
Synergists: latissimus dorsi, subscapularis;

* helps form triangular space & quadrangular space

Teres major tendon transfer for patients with massive irreparable posterosuperior rotator cuff tears. Short-term clinical results