Name

# Extensor Hallucis Longus

Pronunciation

(eks-TEN-sor HA-loo-sus LONG-gus)

Origin/Proximal Attachment

Medial aspect of fibula – middle ½

Adjacent anterior surface of interosseous membrane

Crural fascia

Insertion/Distal Attachment

Dorsal surface of base of proximal & distal phalanx of hallux (big toe)?

(At the MTP joint a thin prolongation from each side of the tendon covers the dorsal surface of the joint)

(An expansion from the medial side of the tendon to the base of the proximal phalanx is usually present)

Action/Relevance

Extends the distal phalanx of big toe

Weakly dorsiflexes foot

Weakly inverts & adducts foot

Innervation

Deep peroneal nerve (L4, 5,S1)

Notes

Lies between, & partly deep to, tibialis anterior & extensor digitorum longus

Arises medial to extensor digitorum longus

Anterior tibial vessels & deep peroneal nerve lie between it & tibialis anterior

Its fibres run distally & end in a tendon which forms on anterior border of the muscle

The tendon passes deep to the superior extensor retinaculum & through the inferior extensor retinaculum, crosses to medial side of the anterior tibial vessels