Human Anatomy - Kotsan I. Ya. 2009

Muscles and Fascia of the Lower Limb
Muscles of the Plantar Surface of the Foot
Medial Group of Plantar Foot Muscles

The Medial group of plantar Muscles consists of three muscles: the abductor hallucis, the flexor hallucis brevis, and the adductor hallucis.

The abductor hallucis (m. abductor hallucis) is located superficially along the medial margin of the FOOT. It has two heads: medial and lateral. The medial HEAD (caput mediale) originates from the inferior extensor retinaculum. The lateral head (caput laterale) originates from the calcaneal tuberosity. The Muscle inserts into the medial sesamoid bone of the great toe and the Base of the proximal phalanx of the great toe on its medial side. Function: abducts and flexes the great toe, and reinforces the first longitudinal arch of the foot.

Innervation: medial plantar nerve (LV—SI).

The flexor hallucis brevis (m. flexor hallucis brevis) is situated on the plantar surface of the first metatarsal bone. It originates from the plantar surface of the cuboid and cuneiform bones and the plantar ligaments. It inserts into the lateral and medial sesamoid bones and the base of the proximal phalanx of the great toe. Function: flexes the great toe and reinforces the first longitudinal arch of the foot.

Innervation: medial part of the muscle — medial plantar nerve (SI—SII), lateral part of the muscle — lateral plantar nerve (LV—SI).

The adductor hallucis (m. adductor hallucis) lies deeply, directly on the Metatarsal Bones, and is covered by the flexor digitorum longus and brevis tendons. It has two heads: oblique and transverse. The oblique head (caput obliquum) is stronger and originates from the plantar surface of the cuboid bone, lateral cuneiform bone, bases of the second, third, and fourth metatarsal bones, and the tendon of the fibularis longus muscle. The transverse head (caput transversum) originates from the capsules of the metatarsophalangeal joints of digits III–V and the distal ends of metatarsal bones II–V. Both heads merge into a common tendon that inserts into the lateral sesamoid bone and the base of the proximal phalanx of the great toe. Function: adducts and flexes the great toe. The transverse head reinforces the transverse arch of the foot.

Innervation: lateral plantar nerve (SI—SII).



Last update: 08/08/2026

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