Innervation Motor lateral compartment of leg peroneus longus peroneus brevis Sensory majority of skin on the dorsum of foot, excluding webspace between hallux and second digit (deep peroneal nerve) anterolateral distal 1/3 of leg Reflex none Origin CNS origin terminal branch of the common peroneal nerve nerve roots: L4-S1 Course Bifurcation of the common peroneal nerve begins at the bifurcation of the common peroneal nerve Proximal neck of fibula passes between peroneal muscles and lateral side of extensor digitorum longus gives off motor branches to peroneus longus and brevis Anterolateral distal leg descends and supplies only sensory innervation Deep crural fascia superficial peroneal nerve pierces deep crural Terminal branches medial dorsal cutaneous nerve intermedial dorsal cutaneous nerve Injury & Clinical Conditions Superficial peroneal nerve entrapment mechanism ankle sprains and ankle twisting causing stretching of superficial peroneal nerve compression where the nerve exits the deep fascia of the leg presentation pain and paresthesias over dorsum of foot Direct damage mechanism fractures of the proximal fibula perforating injury to lateral leg presentation loss of eversion motor to peroneus longus and brevis injured loss of sensation over most of dorsal foot and anterolateral aspect of distal leg