Radial Nerve, Anterior View

Description

Originating from the posterior cord of the brachial plexus (C5 to T1), the radial nerve courses from the axilla into the anterior compartment of the arm, positioned posterior to the axillary artery and then descending relative to the proximal humerus. As it travels distally, it approaches the lateral aspect of the arm near the deltoid insertion and begins the transition toward its characteristic spiral trajectory around the humeral shaft. Surrounding osseous landmarks include the clavicle and rib cage superiorly, the scapula and glenohumeral joint laterally, and the humerus continuing to the radius and ulna at the elbow. Nerve fascicles and the neurilemma are rendered with enough clarity to support discussion of peripheral nerve microanatomy without losing the larger topographic relationships. An anterior approach clarifies how radial nerve injury can occur despite the nerve’s classic association with the posterior arm: the proximal segment remains clinically accessible in the axilla and upper arm, where compression can occur with crutch use or prolonged arm abduction, producing wrist drop and sensory loss over the dorsolateral hand. The view also sets up the teaching point that the nerve’s close relationship to the humerus becomes most dangerous at the radial (spiral) groove, a frequent site of neuropraxia with midshaft fractures and callus formation. Seeing the nerve’s descent alongside major vessels helps explain why operative exposure or traumatic hematoma can compromise both neurovascular structures in the arm. Use this artwork in gross anatomy lab manuals, brachial plexus lectures, and clinical correlations for orthopedics, emergency medicine, and anesthesia, including blocks and surgical approaches around the shoulder and humerus. It also fits textbook spreads on upper limb innervation and mechanisms of radial nerve palsy. Anatomical accuracy verified by SciePro's Medical Advisory Board.