Flexor hallucis longus muscle

The Flexor hallucis longus muscle (FHL) is one of the three deep muscles of the posterior compartment of the leg that distally attaches to the plantar surface of the hallux (great or big 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 branches from the sciatic nerve.