This document describes the muscles of the sole of the foot organized into four layers. The first layer includes the abductor hallucis, flexor digitorum brevis, and abductor digiti minimi muscles. The second layer contains the quadratus plantae and lumbrical muscles. The third layer is made up of the flexor hallucis brevis, adductor hallucis, and flexor digiti minimi brevis muscles. The fourth and final layer comprises the dorsal and plantar interossei muscles. Each muscle is described in terms of its origin, insertion, innervation, and function.

1. The Plantar Muscles of the Foot
1.Plantar Aponeurosis (aponeurosis
plantaris; plantar fascia).
First layer
1. Abductor hallucis
2. Flexor digitorum brevis
3. Abductor digiti minimi
Second layer
1.Quadratus plantae (flexor digitorum
accessorius)
2.Lumbricles
Third layer
1.Flexor hallucis brevis
2.Adductor hallucis
3.Flexor digiti minimi brevis
Fourth layer
1.Plantar introssei
2. Dorsal interossei

2. First layer
1. Abductor hallucis
2. Flexor digitorum brevis
3. Abductor digiti minimi

3. Second layer
1.Quadratus plantae(flexor digitorum
accessorius)
2.Lumbricles

4. Third layer
1.Flexor hallucis brevis
2.Adductor hallucis
3.Flexor digiti minimi brevis

5. Fourth layer
1. Dorsal interossei

6. Fourth layer
1.Plantar introssei

7. Muscles of the Sole of the Foot (First Layer)
abductor hallucis
medial tubercle
of calcaneum;
flexor
retinaculum
medial side, base
of proximal
phalanx of big
toe
medial plantar
nerve
flexes, abducts
big toe; supports
medial arch
flexor digitorum
brevis
medial tubercle
of calcaneum
middle phalanx
of four lateral
toes
medial plantar
nerve
flexes lateral four
toes; supports
medial & lateral
longitudinal
arches
abductor digiti
minimi
medial & lateral
tubercles of
calcaneum
lateral side base
of proximal
phalanx 5th toe
lateral plantar
nerve
flexes, abducts
5th toe; supports
lateral
longitudinal arch

8. muscles of Sole of Foot (Second Layer)
flexor accessorius
(quadratus plantae)
medial and lateral
sides of calcaneum
tendons flexor
digitorum longus
lateral plantar
nerve
aids long flexor
tendon to flex
lateral four toes
lumbricals
tendons of flexor
digitorum longus
dorsal extensor
expansion of lateral
four toes
1st lumbrical from
medial plantar;
remainder
lumbricals from
deep branch of
lateral plantar
nerve
extends toes at
interphalangeal
joints

9. Muscles of Sole of Foot (Third Layer)
flexor hallucis
brevis
cuboid, lateral
cuneiform
bones; tibialis
posterior
insertion
medial & lateral
sides of base of
proximal phalanx
of big toe
medial plantar
nerve
flexes
metatarsophalan
geal joint of big
toe; supports
medial
longitudinal arch
adductor hallucis
(oblique head)
bases of 2nd, 3rd
& 4th metatarsal
bones
lateral side base
of proximal
phalanx big toe
deep branch of
lateral plantar
flexes big toe,
supports
transverse arch
adductor hallucis
(transverse
head)
plantar
ligaments
lateral side of
base of proximal
phalanx big toe
deep branch of
lateral plantar
nerve
flexes big toe;
supports
transverse arch
flexor digiti
minimi brevis
base of 5th
metatarsal bone
lateral side of
base of proximal
phalanx of big
toe
superior branch
of lateral plantar
nerve
flexes little toe

10. Muscles of Sole of Foot (Fourth Layer)
dorsal interossei
(4)
adjacent sides of
metatarsal bones
bases of
phalanges and
dorsal expansion
of corresponding
toes
lateral plantar
nerve
abduct toes with
2nd toe as the
reference; flex
metatarsophalan
geal joints;
extend
interphalangeal
joint
plantar interossei
(3)
3rd, 4th, and 5th
metatarsal bones
bases of
phalanges &
dorsal expansion
of corresponding
toes
lateral plantar
nerve
adduct toes with
2nd toe as
reference; flex
metatarsophalan
geal joints;
extend
interphalangeal
joints