Anatomy, Bony Pelvis and Lower Limb: Calf Deep Peroneal Nerve (Deep Fibular Nerve)

The deep fibular nerve, alternatively termed the deep peroneal nerve, is a terminal division of the common fibular nerve, which originates from spinal nerves L4 to S2 via the sciatic nerve. This peripheral nerve contains both motor and sensory fibers and is, therefore, classified as a mixed nerve. The motor component innervates muscles in the anterior compartment of the leg and the dorsal intrinsic muscles of the foot, enabling dorsiflexion of the foot, extension of the toes, and assisting in foot inversion. The sensory component provides cutaneous innervation to the 1st web space, the skin between the great toe and the 2nd toe. The deep fibular nerve has also been referred to as the "anterior tibial nerve" in some sources, distinct from the tibial nerve, due to its close relationship with the anterior tibial artery during its course through the leg. Clinically, the deep fibular nerve is most commonly associated with foot drop, a consequence of impaired dorsiflexion.