Superficial Fibular Nerve

Question 1

Nerve roots?

Motor function?

Sensory function?

Answer 1

L4-S1

Motor: Innervates the muscles in the lateral compartment of the leg.

Sensory: Supplies the vast majority of the skin over the dorsum of the foot, apart from the webbing between the hallux and the second digit. It also supplies the anterior and lateral aspect of the inferior third of the leg.

Question 2

Nerve course?

Answer 2

It arises at the neck of the fibula, descending between the fibularis muscles and the lateral side of the extensor digitorum longus. Here, it gives rise to motor branches, which supply the fibularis longus and brevis. The nerve continues its descent, with a purely cutaneous function, providing sensory innervation to the anterolateral aspect of the lower leg.

When the superficial fibular nerve reaches the lower third of the leg, it pierces the deep crural fascia and terminates by dividing into the medial and intermedial dorsal cutaneous nerves. These nerves enter the foot to innervate the majority of its dorsal surface.

Question 3

Sensory portions?

Answer 3

Innervates the skin over the anterolateral leg, via cutaneous branches directly from the superficial fibular nerve.

Innervates the skin of the dorsum of the foot (except the webbed space between the hallux and the 2nd digit),
via the medial and intermedial dorsal cutaneous nerves.

The dermatomes to which these areas correspond are L5 and S1.