Anatomical Structure and Location of the Axillary Nerve, Anterior View

Description

Arising from the posterior cord of the brachial plexus (C5 to C6), the axillary nerve courses laterally in the axilla deep to the clavicle and anterior to the scapula before turning posteriorly around the surgical neck of the humerus. From an anterior perspective, its path can be followed as it approaches the inferior aspect of the glenohumeral joint capsule and the subscapularis surface, then disappears toward the quadrangular space bordered by teres minor (superior), teres major (inferior), the long head of triceps (medial), and the humerus (lateral). The humeral head sits lateral to the glenoid cavity, with portions of the scapular neck and adjacent ribs framing the corridor where the nerve transitions from the axilla to the posterior shoulder. Close proximity to the capsule is the point. That relationship matters in two places clinicians care about: dislocation and the deltoid. An anterior glenohumeral dislocation can stretch or compress the axillary nerve as the humeral head translates anteroinferiorly, producing deltoid weakness and sensory loss over the superior lateral arm (the regimental badge area) via the superior lateral cutaneous nerve of arm. The same anatomy explains risk during shoulder arthroscopy and open approaches near the inferior capsule, and during intramuscular injection placement when the needle drifts too distal on the deltoid. Use this anterior shoulder illustration for brachial plexus teaching in gross anatomy and neuroanatomy courses, for orthopaedic and sports medicine texts discussing dislocation patterns, and for operative manuals that map safe zones during capsular work and deltoid-splitting approaches. It also supports patient-facing diagrams when documenting postoperative axillary neuropraxia. Anatomical accuracy verified by SciePro's Medical Advisory Board.