Lower limb

Extensor hallucis brevis

Musculus extensor hallucis brevis

Origin

Dorsal surface of the calcaneus (sinus tarsi region, shared with extensor digitorum brevis)

Insertion

Dorsal aponeurosis/base of the proximal phalanx of the great toe

Function

Extension of the great toe at the MTP joint

Innervation

Deep fibular (peroneal) nerve, L5-S1

Movement & chain

Works together with extensor hallucis longus in extension of the great toe at the MTP joint, particularly during extension without simultaneous IP extension.

Palpation

Palpable on the dorsolateral midfoot just distal to the ankle during active hallux extension.

Clinical

Key muscle for testing deep fibular nerve (L5 root) integrity; isolated weakness or atrophy indicates L5 radiculopathy or anterior tarsal tunnel syndrome.

Segmental innervation

L5–S1 (deep fibular nerve)

In clinical practice

Diabetic foot inspection and pressure ulcer prevention; monitor for friction points from footwear or bedding and ensure correct anti-embolism stocking fit.

Region in the model

Lower limb