brachioradialis

The brachioradialis is a superficial muscle of the forearm located on the lateral (radial) side. It runs from the upper arm to the forearm and is most easily felt when the elbow is flexed.

Origin and insertion: It originates from the proximal two-thirds of the lateral supracondylar ridge of the humerus and the adjacent intermuscular septum. It inserts on the distal radius, at the process near the radial styloid.

Innervation and blood supply: The muscle is innervated by the radial nerve (typically C5–C7). Its arterial supply is primarily via the radial recurrent artery, with contributions from branches of the radial artery.

Function: The brachioradialis flexes the elbow. It is most effective when the forearm is in a neutral (midpronated) position and acts as a synergist with other elbow flexors during rapid or resisted flexion. It does not prime pronation or supination but can help stabilize the forearm during movements that involve these actions.

Clinical significance: The brachioradialis tendon is a useful anatomical landmark in the lateral forearm. The brachioradialis reflex, elicited by tapping the tendon about 1–2 inches above the wrist, tests the radial nerve and typically produces elbow flexion, assessing the C6 nerve root function.

Name and overview: The term brachioradialis reflects its location near the brachium (arm) and the radius, highlighting its role in forearm movement.