Located along the outer border of the foot, the abductor digiti minimi (foot) is a muscle that shares its central margin with the lateral plantar nerves and vessels. The muscle begins at the calcaneal tuberosity (the back part of heel bone) and the plantar aponeurosis (the thick, connective tissue that runs along the sole of the foot).
The abductor digiti minimi inserts on the fibular (outer) side at the base of the first phalanx (bone) of the little toe. The muscle is the first layer of the plantar muscles. This muscle controls the movement of the metatarsophalangeal joint located between the base of the little toe and the head of the fifth metatarsal bone. It is what allows the little toe to flex and move. In rare cases of polydactyly, a condition where a person has extra digits, the muscle connects to the sixth toe.
The abductor digiti minimi is often injured due to its location during physical activity where a person is upright. This muscle can play a role in plantar fasciitis, inflammation of the connective tissue in the sole of the foot.