Upper Arms in Posterior View in the Body

Description

Posteriorly, the brachial region is dominated by the triceps brachii, with the long head arising from the infraglenoid tubercle and running inferiorly between the teres major region and the posterior humerus, while the lateral and medial heads occupy the posterolateral and posteromedial aspects of the arm. Distally, the three heads converge into the common triceps tendon inserting on the olecranon of the ulna, forming the superficial contour just proximal to the elbow. Along the lateral margin near the distal arm, the groove between triceps and brachialis marks the interval where the radial nerve and profunda brachii artery course before sweeping anteriorly toward the cubital fossa and proximal antebrachium. Clear surface anatomy. This posterior emphasis matters when teaching elbow extension mechanics and when localizing nerve injury. Radial nerve palsy from humeral shaft fractures (classically in the spiral groove) weakens triceps to varying degrees depending on lesion level and produces wrist and finger drop, so the relationship between posterior humerus and the triceps mass helps explain the pattern. The long head also influences shoulder stability and adduction, a point often missed when triceps is treated as only an elbow extensor. Use this figure for musculoskeletal anatomy lectures on the upper limb, for physical examination guides that map posterior arm landmarks prior to palpation or EMG, and for orthopedic or sports medicine publications discussing posterior arm pain, tendon injury at the olecranon, or radial nerve entrapment patterns. Anatomical accuracy verified by SciePro's Medical Advisory Board.