Teres Major Muscle As, Posterior View

Description

Positioned along the posteroinferior shoulder, the teres major arises from the dorsal surface of the inferior angle and adjacent lateral border of the scapula, then runs superolaterally toward the proximal humerus. From this posterior perspective, the muscle belly sits inferior to teres minor and posterior to the scapula’s costal surface, with its tendon coursing toward the medial lip of the intertubercular sulcus (crest of the lesser tubercle). The long head of triceps typically lies medial to it near the axillary border, while the humeral head and glenoid region provide the proximal bony context. Clear layering matters here. Functionally, teres major acts with latissimus dorsi to extend, adduct, and medially rotate the humerus, but this view earns its keep by clarifying surgical and exam landmarks around the quadrangular and triangular spaces. The teres major forms the inferior boundary of the quadrangular space (with teres minor superiorly), a key corridor for the axillary nerve and posterior circumflex humeral artery; it also contributes to the boundaries used to localize posterior shoulder pain patterns and to plan posterior approaches that risk iatrogenic traction or compression of these structures. Distinguishing teres major from the rotator cuff is a frequent teaching point, since it does not attach to the greater or lesser tubercles and does not stabilize the glenohumeral joint in the same way. Ideal use cases include gross anatomy and kinesiology teaching on scapulohumeral musculature, operative anatomy figures for posterior shoulder exposures, and rehabilitation materials explaining loss of adduction and internal rotation strength after axillary surgery or tendon transfer planning (for example, latissimus and teres major transfers in brachial plexus palsy). Anatomical accuracy verified by SciePro's Medical Advisory Board.