Question

Between what muscle does the posterior interosseous branch of the radial nerve enter as it reaches the forearm?

Answer 1

The posterior interosseous branch of the radial nerve enters the forearm between the supinator muscle and the abductor pollicis longus, passing along the posterior surface of the distal ulna and the interosseous membrane.

Step-by-step explanation:

The posterior interosseous branch of the radial nerve enters the forearm between the two muscles of the deep posterior compartment of the forearm, which include the supinator muscle and the abductor pollicis longus. The posterior interosseous branch of the radial nerve enters the forearm between the supinator muscle and the abductor pollicis longus, passing along the posterior surface of the distal ulna and the interosseous membrane.

The supinator muscle is essential as it moves the palm and forearm anteriorly. Before reaching these muscles, the radial nerve travels along the posterior surface of the distal ulna and the interosseous membrane.