Flexor digitorum brevis muscle

Flexor digitorum brevis muscle
Flexor digitorum brevis muscle
	Muscles of the sole of the foot. First layer. (Flexor digitorum brevis visible at center.)
	The plantar arteries. Superficial view. (Flexor digitorum brevis visible at center.)
Details
Origin	Calcaneus
Insertion	Middle phalanges of toe 2-5
Artery	Medial and lateral plantar arteries and plantar arch, plantar metatarsal and plantar digital arteries
Nerve	Medial plantar nerve
Actions	Flexion of the lateral four digits
Antagonist	Extensor digitorum longus and extensor digitorum brevis
Identifiers
Latin	musculus flexor digitorum brevis
TA98	A04.7.02.067
TA2	2683
FMA	37450
	Anatomical terms of muscle [edit on Wikidata]

The flexor digitorum brevis or flexor digitorum communis brevis^[1] is a muscle which lies in the middle of the sole of the foot, immediately above the central part of the plantar aponeurosis, with which it is firmly united.

Its deep surface is separated from the lateral plantar vessels and nerves by a thin layer of fascia.

Structure

It arises by a narrow tendon, from the medial process of the tuberosity of the calcaneus, from the central part of the plantar aponeurosis, and from the intermuscular septa between it and the adjacent muscles.

It passes forward, and divides into four tendons, one for each of the four lesser toes.

Opposite the bases of the first phalanges, each tendon divides into two slips, to allow of the passage of the corresponding tendon of the flexor digitorum longus; the two portions of the tendon then unite and form a grooved channel for the reception of the accompanying long Flexor tendon.

Finally, it divides a second time, and is inserted into the sides of the second phalanx about its middle. The mode of division of the tendons of the flexor digitorum brevis, and of their insertion into the phalanges, is analogous to that of the tendons of the flexor digitorum superficialis in the hand.

Innervation

Innervation is by the medial plantar nerve.

Variation

Slip to the little toe may occasionally be absent, where it may be replaced by a small fusiform muscle arising from the long flexor tendon or from the quadratus plantæ.

Additional images

Bones of the right foot. Plantar surface.
Coronal section through right talocrural and talocalcaneal joints.
The bottom-most or first layer of muscles in the human foot include the flexor digitorum brevis.