The Radial nerve is the largest and the
terminal branch of the posterior cord receiving fibers from C5-T1. It courses
posterior to the axillary artery and enters the radial groove with the profunda
brachii artery taking a vertical course around the humeral shaft. The radial
nerve innervates all of the muscles of the posterior compartment of the arm
Wrist drop is the most common effect of peripheral neuropathy of the radial nerve.