Flexor hallucis longus

Musculus flexor hallucis longus

MuscularDeep musclesLegLeft and right

View left in 3D View right in 3D

What it is

Powerful deep calf muscle arising from the lower two-thirds of the posterior fibula and interosseous membrane, lateral in the deep compartment; its fleshy fibres extend almost to the ankle.

Function

Flexes the great toe - essential for the final push-off in walking - and assists plantarflexion and inversion.

Size

Belly about 20 cm; about 35 cm with its tendon.

Clinical note

Tendinitis where it passes behind the talus is common in ballet dancers ("dancer's tendinitis") from repeated pointe work.