Adductor hallucis
The action of adductor hallucis may be perceived by placing the thumb plantarly in the first metatarsal interspace and wrapping the hand around the lateral aspect of the foot from the plantar direction. The subject should then be asked to flex the first toe in order to make the muscle contractions of adductor hallucis perceptible beneath the fingers.
Adductor hallucis is made up of two heads of origin, an oblique and a transverse head which unite to form a single tendon of insertion. The oblique head arises from the medial plantar surface of the bases of the 2nd-4th metatarsals and from the tendinous sheath of peroneus longus. The transverse head arises from the deep tranverse metatarsal ligament and the plantar metatarsophalangeal ligaments. As previously mentioned, the transverse and oblique heads of adductor hallucis unite to form a single tendon of insertion which attaches to the lateral sesamoid of the first MPJ as well as the lateral aspect of the base of the proximal phalanx of the hallux. Both heads of adductor hallucis function to adduct the hallux and the oblique head also works to help flex the hallux.