extensor hallucis longus muscle extensor hallucis longus muscle the extensor hallucis longus muscle is a thin skeletal muscle, situated between the tibialis anterior and the extensor digitorum longus. it extends the big toe and dorsiflects the foot. it also assists with foot eversion and inversion. extensor hallucis longus musclethe mucous sheaths of the tendons around the ankle. lateral aspect. (ext. hall. long. labeled at upper left.)animationdetailsoriginarises from the middle portion of the fibula on the anterior surface and the interosseous membraneinsertioninserts on the dorsal side of the base of the distal phalanx of the big toearteryanterior tibial arterynervedeep fibular nervedeep peroneal nerve, l5 (l4-s1)actionsextends (raises) the big toe and assists in dorsiflexion of the foot at the ankle. also is a weak evertor/ invertorantagonistflexor hallucis longus, flexor hallucis brevisidentifierslatinmusculus extensor hallucis longusta98a04.7.02.040ta22650fma22533anatomical terms of muscle structure the extensor hallucis longus muscle arises from the anterior surface of the fibula for about the middle two-fourths of its extent, medial to the origin of the extensor digitorum longus muscle. it also arises from the interosseous membrane of the leg to a similar extent. the anterior tibial vessels and deep fibular nerve lie between it and the tibialis anterior. the fibers pass downward, and end in a tendon, which occupies the anterior border of the muscle, passes through a distinct compartment in the cruciate crural ligament, crosses from the lateral to the medial side of the anterior tibial vessels near the bend of the ankle, and is inserted into the base of the distal phalanx of the great toe. opposite the metatarsophalangeal articulation, the tendon gives off a thin prolongation on either side, to cover the surface of the joint. an expansion from the medial side of the tendon is usually inserted into the base of the proximal phalanx. nerve supply the extensor hallucis longus muscle is supplied by the deep fibular nerve, a branch of common fibular nerve, which includes l4, l5, and s1 spinal nerve roots. variations occasionally united at its origin with the extensor digitorum longus. the extensor ossis metatarsi hallucis, a small muscle, sometimes found as a slip from the extensor hallucis longus, or from the tibialis anterior, or from the extensor digitorum longus, or as a distinct muscle; it traverses the same compartment of the transverse ligament with the extensor hallucis longus. function the extensor hallucis longus muscle extends the big toe, dorsiflects the foot, and also assists with foot eversion and inversion. additional images cross-section through middle of leg. (extensores longi digitorum et hallucis labeled at upper left.) dorsum of foot. deep dissection. dorsum of foot. deep dissection. ankle joint. deep dissection. medial view ankle joint. deep dissection. lateral view.