Flexor hallucis longus

The flexor hallucis longus muscle (FHL) is one of the three deep muscles of the posterior compartment of the leg that attaches to the plantar surface of the distal phalanx of the great toe. The other deep muscles are the flexor digitorum longus and tibialis posterior; the tibialis posterior is the most powerful of these deep muscles. All three muscles are innervated by the tibial nerve which comprises half of the sciatic nerve.Muscles of the back of the leg. Deep layer.Muscles of the sole of the foot. Second layer.Muscles of the sole of the foot.Muscles of the back of the leg. Deep layer.Muscles of the back of the leg. Deep layer.Muscles of the leg.Posterior viewMuscles of the sole of the foot.Muscles of the sole of the foot.Dorsum and sole of Foot. Ankle joint. Deep dissection.Ankle joint. Deep dissection. Medial view The flexor hallucis longus muscle (FHL) is one of the three deep muscles of the posterior compartment of the leg that attaches to the plantar surface of the distal phalanx of the great toe. The other deep muscles are the flexor digitorum longus and tibialis posterior; the tibialis posterior is the most powerful of these deep muscles. All three muscles are innervated by the tibial nerve which comprises half of the sciatic nerve. The flexor hallucis longus is situated on the fibular side of the leg. It arises from the inferior two-thirds of the posterior surface of the body of the fibula, with the exception of 2.5 cm. at its lowest part; from the lower part of the interosseous membrane; from an intermuscular septum between it and the peronius muscles, laterally, and from the fascia covering the tibialis posterior, medially.