The anterior interosseous nerve is a branch of the median nerve that can be selectively injured. Which specific muscles does it innervate?

• A All flexor digitorum profundus fibers and flexor carpi radialis
• B Flexor digitorum superficialis and abductor pollicis brevis
• C Flexor pollicis longus, pronator quadratus, and flexor digitorum profundus to index and middle fingers ✓
• D Pronator teres, flexor carpi radialis, and palmaris longus

Explanation

The anterior interosseous nerve (a branch of the median nerve arising in the forearm) innervates three muscles: flexor pollicis longus (FPL), pronator quadratus (PQ), and the lateral half of flexor digitorum profundus (FDP, supplying the index and middle fingers). Selective anterior interosseous nerve palsy is identified clinically by the inability to form the 'OK sign' — the patient cannot pinch the thumb tip to the index fingertip because FPL and FDP to the index finger are paralyzed.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.