Lateral Perspective Of The Teres Major

Description

Seen in lateral profile, the teres major arises from the dorsal surface of the inferior angle and adjacent lateral border of the scapula and courses anterolaterally toward the proximal humerus. Its tendon passes anterior to the long head of triceps near the posterior axillary fold and inserts on the medial lip of the intertubercular sulcus (crest of the lesser tubercle), lying just posterior and inferior to the tendon of latissimus dorsi. Surrounding osseous landmarks include the scapular spine and body posteriorly, the humeral head at the glenohumeral joint superiorly, and the rib cage deep to the scapula. A lateral perspective is the cleanest way to teach how teres major relates to the quadrangular space and the posterior axillary fold, where it forms a palpable inferior boundary with latissimus dorsi. That relationship matters in axillary and posterior shoulder surgery, when you need to orient to the surgical interval around the long head of triceps and avoid traction on the axillary nerve and posterior circumflex humeral artery passing through the quadrangular space. It also frames why loss of internal rotation and adduction strength can follow lower scapular injuries or scarring around the medial bicipital groove. Use this illustration for gross anatomy lab guides, kinesiology lectures on shoulder extension and internal rotation, and operative anatomy figures accompanying posterior shoulder approaches or axillary dissection chapters. It also suits radiology teaching files when correlating posterior shoulder muscle contours on MRI or ultrasound. Anatomical accuracy verified by SciePro's Medical Advisory Board.