Which nerve supplies the majority of flexors in the forearm?

• A. Ulnar
• B. Median
• C. Radial
• D. Axillary

Answer: (B)

Forearm flexion is carried out mainly by muscles in the anterior compartment, and their nerve supply comes mostly from the median nerve. The median nerve innervates the bulk of these flexors—such as flexor carpi radialis, flexor digitorum superficialis, palmaris longus, and flexor pollicis longus—and also supplies the lateral part of flexor digitorum profundus via the anterior interosseous branch. The two notable exceptions are flexor carpi ulnaris and the medial portion of flexor digitorum profundus, which receive input from the ulnar nerve. The radial nerve supplies the extensors in the posterior compartment, and the axillary nerve supplies the deltoid and teres minor, not forearm flexors.