Lower limb

Fibularis brevis

Musculus fibularis brevis

Origin

Distal half of the lateral surface of the fibula

Insertion

Tuberosity of the fifth metatarsal bone

Function

Eversion (pronation) of the foot and support of plantarflexion

Innervation

Superficial fibular (peroneal) nerve, L5-S1

Movement & chain

Together with fibularis longus, stabilizes the lateral ankle on uneven ground and counteracts inversion injuries by actively everting the foot.

Palpation

Can be followed behind the lateral malleolus to the base of the fifth metatarsal bone, readily palpable during resisted active eversion.

Clinical

The tendon can avulse a fragment in a fracture of the base of the fifth metatarsal bone (pseudo-Jones fracture caused by tendon traction).

Segmental innervation

L5–S1 (superficial fibular nerve)

In clinical practice

Eversion strength of this muscle is tested when evaluating chronic ankle instability, and the tendon can subluxate or dislocate behind the lateral malleolus in traumatic tendon dislocation.

Region in the model

Lower limb