The anterior interosseous nerve is a branch of the median nerve. It arises from the median nerve just distal to the antecubital fossa, about 5.5 cm distal to the medial epicondyle of the humerus. [2] It passes along the interosseous membrane between the ulna and radius. It terminates in the pronator quadratus muscle around the level of the wrist. It is largely a motor nerve. It supplies the fle...