Flexor digitorum longus
Origin:Posterior surface of 1/3 of tibia
Insertion: Inferior surface of distal phalanges 2-5
Action:
Planter flexion
Inversion of the foot Flexion of the distal joint 2-5
Nerve innervation: Deep peroneal branch of tibia nerveL4-S2
Tibialis posterior
Origin: Interosseous membrane, Posterior surface of tibia, Superior 2/3 of medial surface of fibula
Insertion: Navicular, 3th cuneiforms, cuboid and metatarsal 2-4
Action: Planter flexion and inversion of the foot Adduction of the foot
Nerve innervation: Tibial nerve L5-S1
Flexor hallucis Longus
origin: Inferior 2/3 of the posterior fibula and inferior interosseous membrane
Insertion: Inferior surface of distal phalanx(big toe)
Action: Planter flexion and inversion of the footFlexion of distal phalanx
Nerve innervation: Tibial nerve, deep fibular(peroneal) branch L4-S2
*These muscles are related to Tarsal tunnel syndrome.
*From medial side, tibialis posterior, flexor digitorum longus and flexor hallucis longus tendons run under flexor retinaculum.
*Tib post might be related to Shin splint.
