Image by/from Dr. Johannes Sobotta
The abductor hallucis muscle lies in the medial border of the foot and adds to form the prominence that is observed on the area. It is inserted behind on the tuberosity of the calcaneus, the flexor retinaculum, and the plantar aponeurosis. Its muscle body, reasonably thick behind, flattens as it moves forward. It ends in a typical tendon with the medial head of the flexor hallucis brevis that inserts on the medial surface area of the base of the very first proximal phalanx and its associated sesamoid bone. Its medial surface area is superficial and covered with the muscle’s fascia and the skin.
Abductor hallucis is provided by the medial plantar nerve. The nerves that provide it get in the muscle from its upper border.
Superficial dissection of the sole of the foot, showing the medial eminence formed by abductor hallucis
Abductor hallucis muscle
Coronal section through right talocrural and talocalcaneal joints