Teres major muscle

Teres major is a muscle of the upper limb and one of six scapulohumeral muscles. It is a thick but somewhat flattened muscle.

Origin and insertion
It arises from the oval area on the dorsal surface of the inferior angle of the scapula, and from the fibrous septa interposed between the muscle and the Teres minor and Infraspinatus

The fibers of teres major insert into the medial lip of the bicipital groove of the humerus.

Relations


The tendon, at its insertion, lies behind that of the Latissimus dorsi, from which it is separated by a bursa, the two tendons being, however, united along their lower borders for a short distance.

Together with teres minor muscle, teres major muscle forms the axillary space, where several important arteries and veins pass through.

Action
The Teres major assists the Latissimus dorsi in drawing the previously raised humerus downward and backward, and in rotating it inward; when the arm is fixed it may assist the Pectorales and the Latissimus dorsi in drawing the trunk forward.