Upper limb

Teres Major

Musculus teres major

Origin

Inferior angle and lateral border of the scapula

Insertion

Crest of the lesser tubercle of the humerus (medial lip of the intertubercular sulcus)

Function

Internal rotation, adduction, and extension of the shoulder

Innervation

Lower subscapular nerve (C5-C7)

Movement & chain

Functionally works together with latissimus dorsi (both insert close together) in movements such as pulling the arm downward and climbing.

Palpation

Palpable as the posterior border of the axilla, below teres minor, during adduction and internal rotation against resistance.

Clinical

Sometimes used as a muscle donor in reconstructive surgery (tendon transfer) for irreparable rotator cuff tears; overload of the adjacent space can contribute to quadrangular space syndrome with compression of the axillary nerve.

Segmental innervation

Lower subscapular nerve, C5-C7.

In clinical practice

Safe transfer techniques avoiding arm traction (prevents shoulder subluxation in stroke patients); monitor injection sites and offload scapular pressure.

Region in the model

Upper limb