Abductor digiti minimi muscle
Abductor digiti minimi is an unipennate muscle located in the lateral part of the sole of the foot.
As there are horizontal and vertical groupings of foot muscles into four layers and three groups respectively, the full address of this muscle is that it belongs to the;
- First layer of plantar foot muscles, together with the abductor hallucis and flexor digitorum brevis
- Lateral plantar muscles, along with the flexor digiti minimi brevis and opponens digiti minimi
This article will discuss the anatomy and function of the abductor digiti minimi muscle.
|Origin||Calcaneal tuberosity, plantar aponeurosis|
|Insertion||Base of proximal phalanx of digit 5, metatarsal bone 5|
Metatarsophalangeal joint 5: Toe abduction, toe flexion;
Supports longitudinal arch of foot
|Innervation||Lateral plantar nerve (S1-S3)|
|Blood supply||Lateral plantar artery|
Origin and insertion
Abductor digiti minimi muscle originates from the plantar aponeurosis, lateral and medial processes of calcaneal tuberosity and the area between them. It courses anteriorly through the lateral part of the foot, giving off a tendon that inserts to the base of proximal phalanx of 5th digit and 5th metatarsal bone.
The part of the muscle that inserts onto the 5th metatarsal is the one originating from the lateral process of calcaneal tuberosity. These fibers can sometimes form a separate muscle called the abductor ossis metatarsi digiti quinti.
This muscle lies deep to lateral plantar fascia and superficial flexor digiti minimi brevis. Lying along the lateral border of the foot, abductor digiti minimi is the most lateral muscle of the first layer. Medial to it are the flexor digiti minimi brevis muscle and the lateral plantar artery and nerve.
Abductor digiti minimi is innervated by the lateral plantar nerve (S1, S3), a branch of the tibial nerve.
This muscle is supplied by the branches of lateral plantar artery; plantar metatarsal and plantar digital arteries to 5th digit.
Its function is analogous to that of the abductor hallucis muscle from the opposite side of the foot; it maintains the concavity of the foot by supporting the lateral longitudinal arch during walking, running and jumping.
Learn about the functions of abductor digiti minimi and other lateral plantar muscles with Kenhub’s 3D video tutorial.