3rd and 4th plantar layers of the foot (English)

The third layer is composed of the flexor hallucis brevis, adductor hallucis and flexor digiti minimi brevis muscles. The flexor hallucis brevis muscle arises from the cuboid via its lateral head and from the tendon of the tibialis posterior muscle and medial intermuscular septum via its medial head. Both heads run anteromedially towards the great toe, inserting onto each side of the base of the proximal phalanx of the hallux. The adductor hallucis muscle similarly arises by way of two heads: an oblique and transverse head. It’s oblique head originates from the bases of metatarsal bones 2-4, cuboid, lateral cuneiform bones and the tendon of fibularis longus, while it’s transverse head extends from the plantar metatarsophalangeal ligaments of toes 3-5 and deep transverse metatarsal ligaments to reach and attach onto the base of the proximal phalanx of the great toe. The flexor digiti minimi brevis muscle is part of the lateral muscle group and acts on the fifth toe. It originates from the base of metatarsal 5 and extends to insert onto the proximal phalanx of the little toe. The fourth layer of plantar muscles consist of the plantar and dorsal interossei which are located in the central compartment of the foot. The dorsal interossei are best viewed from a dorsal perspective of the foot (see previous image). The plantar interossei are three muscles which arise from the medial plantar aspect of the metatarsals 3-5, respectively and insert onto the medial bases of the proximal phalanges and extensor expansion of toes 3-5.