Lower Subscapular Nerve, Anterior View

Description

Arising from the posterior cord of the brachial plexus (predominantly C5 to C6), the lower subscapular nerve is traced from the axillary region toward the anterior surface of the scapula, coursing inferiorly along the subscapularis on the costal (anterior) scapular fossa. Medial to the surgical neck of the humerus and deep to the clavicle and anterior shoulder girdle, the nerve descends toward the inferior border of the scapula where it typically contributes motor branches to teres major and the inferior portion of subscapularis. Portions of the scapula, proximal humerus, and adjacent rib cage frame its relationship to the thorax. Small but clinically consequential. An anterior view clarifies why the subscapular nerves are discussed in relation to axillary surgery and posterior cord lesions, because their short course and close proximity to the axillary vessels place them at risk during lymph node dissection, coracoid-based exposure, or traumatic stretch in shoulder dislocation. Weakness of subscapularis and teres major can appear as impaired internal rotation and adduction, and it can be mistaken for a rotator cuff tear unless you keep the nerve supply in mind. This perspective also helps distinguish the lower subscapular nerve from the thoracodorsal nerve, which tracks more consistently to latissimus dorsi. Use it in a brachial plexus lab, a surgical anatomy chapter on the axilla and shoulder, or a teaching file that contrasts nerve injury patterns after axillary approaches and proximal humeral trauma in adult male patients. Anatomical accuracy verified by SciePro's Medical Advisory Board.