The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all
Radial nerve of the right axilla, posterior view
Muscles of the posterior forearm. All the labelled muscles (that is, all the visible muscles except the ones on the dorsal hand and one at top right) are innervated by the radial nerve, and represent all muscles innervated by the radial nerve except for the supinator.