Flexor Digitorum Brevis (Musculus flexor digitorum brevis)
Educational content only — not medical advice.
Anatomy
The central muscle of the first (superficial) layer of the sole, immediately deep to the plantar aponeurosis. Its four tendons fan out to the lateral four toes; each tendon splits at the base of the proximal phalanx to let the long flexor (flexor digitorum longus) pass through, then inserts on the sides of the middle phalanx — the same perforatus–perforans arrangement seen in the hand.
Origin & insertion
From the medial process of the calcaneal tuberosity and the plantar aponeurosis, to the sides of the middle phalanges of the lateral four toes.
Action
Flexes the proximal interphalangeal joints of the lateral four toes.
Innervation
Medial plantar nerve (S1–S2).
Clinical notes
The slip to the little toe is frequently absent as an anatomical variant. Overuse from barefoot running or hard-soled footwear inflames its tendons under the metatarsal heads (metatarsalgia pattern), and its tendons are the landmarks for plantar-plate injuries of the second toe.
Related structures
Educational references
FAQ
What is the role of the Flexor Digitorum Brevis?
The central muscle of the first (superficial) layer of the sole, immediately deep to the plantar aponeurosis. Its four tendons fan out to the lateral four toes; each tendon splits at the base of the proximal phalanx to let the long flexor (flexor digitorum longus) pass through, then inserts on the sides of the middle phalanx — the same perforatus–perforans arrangement seen in the hand.
Why is the Flexor Digitorum Brevis clinically important?
The slip to the little toe is frequently absent as an anatomical variant. Overuse from barefoot running or hard-soled footwear inflames its tendons under the metatarsal heads (metatarsalgia pattern), and its tendons are the landmarks for plantar-plate injuries of the second toe.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details