Flexor hallucis longus muscle

The flexor hallucis longus muscle (FHL) is one of the deep muscles of the posterior compartment of the leg. It is a powerful muscle that plays a crucial role in the movement of the big toe and the ankle joint.

Anatomy

The flexor hallucis longus muscle originates from the posterior aspect of the middle third of the fibula and the adjacent interosseous membrane. It travels down the leg, passing through the tarsal tunnel and inserting into the base of the distal phalanx of the great toe.

Blood Supply

The FHL receives its blood supply from the peroneal artery, a branch of the posterior tibial artery.

Innervation

The muscle is innervated by the tibial nerve, specifically the S2 and S3 nerve roots.

Function

The primary function of the flexor hallucis longus muscle is to flex all the joints of the big toe. Additionally, it assists in the plantar flexion of the ankle joint. This muscle is essential for activities such as walking, running, and maintaining balance.

Clinical Significance

Injuries or conditions affecting the FHL can lead to difficulties in toe flexion and ankle movement. Common issues include tendinitis and tenosynovitis, which can cause pain and limit mobility.

See Also

• Flexor digitorum longus muscle
• Extensor hallucis longus muscle
• Posterior tibial artery
• Tibial nerve