Lumbar Plexus V2 Practice Test

The deep fibular nerve is responsible for innervating the extensor digitorum longus. This muscle sits in the anterior compartment of the leg and extends the lateral toes, aided by dorsiflexion of the foot. The deep fibular nerve is the branch of the common fibular nerve that travels with the anterior compartment muscles, supplying their motor fibers, including extensor digitorum longus, extensor hallucis longus, and the tibialis anterior. It also provides sensation between the first and second toes. The other nerves don’t fit because the tibial nerve supplies the posterior compartment and the plantar surface; the superficial fibular nerve innervates the lateral (fibularis) muscles and provides dorsum foot sensation except for the web space between the first two toes; the common fibular nerve gives off the deep branch that does the actual extensor work, but the direct innervation of the extensor digitorum longus is the deep fibular nerve.