Abductor hallucis

The abductor hallucis muscle is an intrinsic muscle of the foot located along its medial aspect. It originates from the medial process of the calcaneal tuberosity and the flexor retinaculum. The muscle runs anteriorly and inserts onto the medial side of the base of the proximal phalanx of the great toe (hallux), often via the medial sesamoid bone. Functionally, it acts to abduct and assist in flexion of the hallux at the metatarsophalangeal joint, and plays a key role in supporting and elevating the medial longitudinal arch of the foot. Its innervation is provided by the medial plantar nerve.

Origin: Tuberosity of the calcaneus

Insertion: Medial aspect of base of proximal phalanx of hallux

Nerve: Medial plantar nerve

Action: Abducts hallux

Antagonist: Adductor hallucis muscle

Description: 

The Abductor hallucis lies along the medial border of the foot and covers the origins of the plantar vessels and nerves. It arises from the medial process of the tuberosity of the calcaneus, from the laciniate ligament, from the plantar aponeurosis, and from the intermuscular septum between it and the Flexor digitorum brevis. The fibers end in a tendon, which is inserted, together with the medial tendon of the Flexor hallucis brevis, into the tibial side of the base of the first phalanx of the great toe.

Variations.—Slip to the base of the first phalanx of the second toe.