The adductor hallucis (also adductor hallucis muscle, latin: musculus adductor hallucis) is a deep two-headed muscle of the sole of the foot belonging to the medial foot muscle group and aiding in adduction of the big toe.
The adductor hallucis is formed by two portions or heads - an oblique and a transverse head, which have different origin sites.
The oblique head of the adductor hallucis originates from the cuboid bone, lateral cuneiform bone, and the base of the second and third metatarsal bones, and from the long plantar ligament.
The transverse head of the adductor hallucis originates from the second to fifth metatarsophalangeal joints.
The adductor hallucis inserts at the base of the proximal phalanx of the hallux.
The adductor hallucis muscle takes part in adduction of the big toe.
Both heads of the adductor hallucis are innervated by the lateral plantar nerve, one of the terminal branches of the tibial nerve.