小趾外転筋 （ しょうしがいてんきん、英：abductor digiti minimi muscle ）
The abductor digiti minimi (abductor minimi digiti, abductor digiti quinti) is a muscle which lies along the lateral (outer) border of the foot, and is in relation by its medial margin with the lateral plantar artery, vein and nerves.
Its homolog in the arm is the abductor digiti minimi muscle in the hand.
【Origin and insertion】
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.
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.[2]
【Innervation】
The abductor digiti minimi is innervated by the lateral plantar nerve, a branch of the tibial nerve.
Its function is flexion and abduction of the fifth (little) toe at the metatarsophalangeal joint.
【 語 句 】
・lateral plantar artery：外側足底動脈 ・homolog：相同物 ・tuberosity：結節 ・calcaneus：踵骨 ・plantar aponeurosis：足底腱膜 ・intermuscular septum：筋間中隔 ・flexor digitorum brevis：短趾屈筋 ・metatarsal bone：中足骨 ・facet：面 ・flexor digiti quinti brevis：短小趾屈筋 ・first phalanx：基節骨 ・tibial nerve：脛骨神経 ・flexion：屈曲 ・abduction：外転 ・metatarsophalangeal joint：中足趾節関節
