The flexor digitorum brevis 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
A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal organ ...
.
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
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
, 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
Flexor digitorum superficialis (''flexor digitorum sublimis'') is an extrinsic flexor muscle of the fingers at the proximal interphalangeal joints.
It is in the anterior compartment of the forearm. It is sometimes considered to be the deepest pa ...
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
File:Gray269.png, Bones of the right foot. Plantar surface.
File:Gray357.png, Coronal section through right talocrural and talocalcaneal joints.
File:1124 Intrinsic Muscles of the Foot b.png, The bottom-most or first layer of muscles in the human foot include the flexor digitorum brevis.
References
External links
* - "The Foot: Muscles"
PTCentral
{{DEFAULTSORT:Flexor Digitorum Brevis Muscle
Foot muscles
Muscles of the lower limb