Posterior Perspective of the Teres Major Muscle

Description

Running along the posteroinferior border of the scapula, the teres major is rendered as a thick spindle-shaped muscle that courses superolaterally to its humeral insertion on the medial lip of the intertubercular sulcus (crest of the lesser tubercle). Superior to it lies teres minor, separated by the long head of triceps brachii as it descends from the infraglenoid tubercle, while the posterior deltoid caps the shoulder laterally and the infraspinatus occupies the infraspinous fossa medially. Inferiorly and medially, teres major blends visually into the lateral margin of latissimus dorsi, together defining the posterior axillary fold against the thoracic wall and scapular plane. Fiber direction is clear. Posterior exposure matters here because teres major is often confused with the rotator cuff on superficial inspection, yet it does not attach to the greater tubercle and does not stabilize the glenohumeral joint like teres minor or infraspinatus. Its relationship to the axillary neurovascular corridor is practical: the teres major forms the inferior boundary of the quadrangular space region, and surgeons working around the posterior axilla and proximal humerus use it as a reliable landmark while protecting the axillary nerve and posterior circumflex humeral artery. Internal rotation and adduction mechanics become easier to teach when you can trace its line of pull from scapula to humerus. Use this artwork in gross anatomy labs, kinesiology and biomechanics lectures on shoulder adduction and extension, and as a figure for sports medicine texts discussing posterior axillary fold anatomy, tendon transfers, or safe planes for posterior shoulder approaches. It also supports patient-facing education when explaining why a strained teres major can mimic latissimus dorsi pain in overhead athletes. Anatomical accuracy verified by SciePro's Medical Advisory Board.