Abductor Digiti Minimi Muscle (abductor minimi digit, abductor digiti quinti) is a muscle that lies along the lateral (outer) border of the foot and is in relation to its medial margin with the lateral plantar artery, vein, and nerves. Its homolog in the arm is the abductor digit minimi muscle in the hand. Its homolog in the arm is the abductor digit minimi muscle in the hand.
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
Extending between the calcaneus and fifth digit, the function of abductor digiti minimi is to support the lateral longitudinal arch of the foot during walking and running by abducting the fifth toe.
Abductor Digiti Minimi
-
Origin: Calcaneal tuberosity
-
Insertion: Base of the fifth metatarsal
-
Action: Abduct the 5th digit
-
Blood Supply: Lateral plantar artery
-
Innervation: Lateral plantar nerve lateral plantar artery
Origin and Insertion of Abductor Digiti Minimi Muscle
It arises, by a broad origin, from the lateral process of the tuberosity of the calcaneus, from the under surface of the calcaneus between the two processes of the tuberosity, from the forepart of the medial process, from the plantar aponeurosis, and from the intermuscular septum between it and the flexor digitorum brevis.[rx]
Its tendon, after gliding over a smooth facet on the under surface of the base of the fifth metatarsal bone, is inserted, with the flexor digiti quinti brevis, into the fibular side of the base of the first phalanx of the fifth toe.
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.
Nerve Supply
- The abductor digiti minimi is innervated by the lateral plantar nerve, a branch of the tibial nerve.
- Abductor digiti minimi is innervated by the lateral plantar nerve (S1, S3), a branch of the tibial nerve.
Blood Supply
This muscle is supplied by the branches of lateral plantar artery; plantar metatarsal and plantar digital arteries to 5th digit.
Functions
- Although called the abductor, besides abducting, this muscle is a much more powerful flexor of the fifth toe at its metatarsophalangeal joint.
- 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.
- Its function is flexion[rx] and abduction of the fifth (little) toe at the metatarsophalangeal joint.[rx][rx]
References