Anatomy, Shoulder and Upper Limb, Forearm Brachioradialis Muscle

The brachioradialis is considered a posterior or extensor-compartment muscle, though it functions as a flexor (see Image. Forearm Muscles). This unique muscle is 1 of 2 forearm extensor-compartment muscles that do not cross the wrist, the other being the supinator. The brachioradialis flexes, pronates, and supinates the forearm but is innervated by the radial nerve. Therefore, weakness of this muscle or its tendon reflex during neurologic examination may indicate a radial rather than a median or ulnar nerve lesion.

Trauma and chronic overuse are the usual causes of brachioradialis impairment. In surgery, the brachioradialis is vital to hand defect reconstruction, forearm tendon transfers, and carpal tunnel release. Understanding this muscle's anatomic and clinical significance is vital to properly evaluating and managing various musculoskeletal conditions.