Flexor hallucis longus

The flexor hallucis longus (also flexor hallucis longus muscle, latin: musculus flexor hallucis longus) is a deep muscle belonging to the posterior group of the lower leg muscles and it lies on the fibular side of the leg.


The flexor hallucis longus originates from the posterior surface of the body of the fibula and from the interosseous membrane of the leg.


The flexor hallucis longus inserts at the distal phalanx of the first digit of the foot, also known as hallux or big toe.


There are several actions provided by the flexor hallucis longus, including flexion, supination and adduction of the foot, as well as flexion of the big toe.


The flexor hallucis longus is innervated by the tibial nerve.