Teres Major Under the Skin, Lateral View

Description

Positioned on the posterolateral trunk beneath the skin, the teres major is highlighted as it arises from the inferior angle and adjacent lateral border of the scapula, then courses superolaterally toward the proximal humerus. Its tendon inserts on the medial lip of the intertubercular sulcus (crest of the lesser tubercle), lying just inferior to the teres minor and posterior to the long head of triceps in the region of the axillary border of the scapula. Surrounding skeletal landmarks include the clavicle and scapula at the shoulder girdle, the thoracic rib cage laterally, and the cervical and thoracic vertebrae aligned posteriorly. Skin-level context is maintained through transparency. Clear landmarks. Teres major matters because its humeral insertion sits immediately adjacent to the latissimus dorsi tendon, a relationship that often confuses learners and affects surgical orientation in the posterior axillary fold. During shoulder examination, pain with resisted adduction and internal rotation can implicate the teres major and latissimus complex, and overuse strains occur in climbers and throwing athletes where repetitive extension from flexion loads the myotendinous junction. The lateral perspective also reinforces how this muscle contributes to internal rotation and adduction while tethering the scapula to the humerus, a useful teaching point when discussing scapulohumeral rhythm. Use this artwork in gross anatomy and kinesiology modules to contrast teres major with rotator cuff musculature, or in orthopedic and sports medicine texts illustrating posterior axillary fold anatomy, tendon insertions on the humerus, and differential diagnosis of posterior shoulder pain. It also supports patient education diagrams for rehabilitation protocols targeting shoulder internal rotators and adductors in the adult male. Anatomical accuracy verified by SciePro's Medical Advisory Board.