Anatomy, Bony Pelvis and Lower Limb: Calf Flexor Hallucis Longus Muscle

In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan.


The flexor hallucis longus (FHL) muscle is one of the four muscles that compose the deep posterior compartment of the lower limb. The other three deep muscles are the flexor digitorum longus (FDL), tibialis posterior, and popliteus muscles. The flexor hallucis longus originates at the posterior surface of the fibula and inserting at the plantar aspect at the base of the distal phalanx of the great toe. The primary function of the flexor hallucis longus is flexion of the great toe, also serving to plantarflex and invert the foot. The antagonistic muscle is the extensor hallucis longus (EHL).

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