Superficial peroneal nerve

Superficial peroneal nerve (also known as the superficial fibular nerve) is a nerve in the lower leg that provides sensory innervation to the skin of the lower leg and the dorsal aspect of the foot, and motor innervation to the muscles of the lateral compartment of the leg. It is a branch of the common peroneal nerve, itself a major branch of the sciatic nerve.

Anatomy

The superficial peroneal nerve originates from the common peroneal nerve at the level of the fibular head in the lower leg. It descends between the peroneus longus and the peroneus brevis muscles, which are part of the lateral compartment of the leg, innervating them. As it travels down the leg, it becomes more superficial and emerges from the lateral compartment to travel down the front of the leg, under the skin.

At the lower part of the leg, near the ankle, it divides into two terminal branches: the medial dorsal cutaneous nerve and the intermediate dorsal cutaneous nerve. These branches provide sensory innervation to the majority of the dorsal aspect of the foot, except for the areas between the first and second toes, which are innervated by the deep peroneal nerve.

Function

The superficial peroneal nerve has both motor and sensory functions:

• Motor: It innervates the peroneus longus and peroneus brevis muscles. These muscles are responsible for eversion of the foot, which is the movement of turning the sole of the foot outward.
• Sensory: It provides sensation to the skin of the lower lateral part of the leg and most of the dorsal part of the foot.

Clinical Significance

Injury to the superficial peroneal nerve can result in sensory loss or changes in sensation in its distribution area and weakness or paralysis of the muscles it innervates. This can lead to difficulty in foot eversion and a gait disturbance known as a steppage gait. Causes of injury can include trauma, compression, or surgery. Diagnosis is typically made through clinical examination and confirmed with nerve conduction studies.

See Also

• Common peroneal nerve
• Deep peroneal nerve
• Sciatic nerve
• Peroneus longus
• Peroneus brevis