Image by/from Henry Vandyke Carter
The abductor digiti minimi (abductor minimi digiti, abductor digiti quinti) is a muscle which lies along the lateral (external) border of the foot, and remains in relation by its median margin with the lateral plantar artery, vein and nerves.
Its homolog in the arm is the abductor digiti minimi muscle in the hand.
It occurs, by a broad origin, from the lateral process of the tuberosity of the calcaneus, from the under surface area of the calcaneus in between the two processes of the tuberosity, from the forepart of the median process, from the plantar aponeurosis, and from the intermuscular septum in between it and the flexor digitorum brevis.
Its tendon, after moving over a smooth element on the under surface area of the base of the 5th metatarsal bone, is placed, with the flexor digiti quinti brevis, into the fibular side of the base of the very first phalanx of the 5th toe.
The abductor digiti minimi is innervated by the lateral plantar nerve, a branch of the tibial nerve.
Due to its function in posture throughout all movement while in an upright position, the abductor digiti minimi is typically the target of injury.
In case of polydactyly it might place to the 6th toe rather, if there is one.
Bones of the right foot seen from below.
Coronal section through right talocrural and talocalcaneal joints.