tibialis posterior (muscle)

tib·i·a·lis pos·te·ri·or (mus·cle)

[TA]
most anterior (deepest) muscle of deep posterior (plantar flexor) compartment of leg; origin, soleal line and posterior surface of tibia, the head and shaft of the fibula between the medial crest and interosseous border, and the posterior surface of interosseous membrane; insertion, navicular, three cuneiform, cuboid, and second, third, and fourth metatarsal bones; action, plantar flexion and inversion of foot; nerve supply, tibial.