Name

# Teres Major

Pronunciation

(TE-rez MA-jor)

Origin/Proximal Attachment

Lower 1/3 of the scapula’s posterior surface & lateral border

Insertion/Distal Attachment

Medial lip of the bicipital groove of the humerus (just medial to the insertion of the latissimus dorsi)

Action/Relevance

Internally rotates the arm

Extends the arm (from a flexed position)

Adducts the arm

Innervation

Lower subscapular nerve (C5, 6)

Notes

The Teres major is a thick but somewhat flattened muscle, which 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 are directed upward and lateralward, and end in a flat tendon, about 5 cm. long, which is inserted into the crest of the lesser tubercle of the humerus. 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.