Download THE MUSCLES OF THE FOOT LEARNING OBJECTIVES At the end

THE MUSCLES OF THE FOOT
LEARNING OBJECTIVES
At the end of the lecture, the student should be able to:

Describe the dorsal muscles of foot.

Tell the origin and insertion of planter muscles of foot.

Explain their nerve supply and actions.
THE DORSAL MUSCLES OF THE FOOT
EXTENSOR DIGITORUM BREVIS:
ORIGIN:
1. Forepart of the upper and lateral surfaces of the
calcaneum.
2. From the inferior extensor retinaculum.
Passes obliquely across the dorsum of the foot, and
ends in four tendons.
INSERTION:
1. Medial, the largest, is inserted into the dorsal
surface of the base of the proximal phalynx of the
great toe—the Extensor hallucis brevis.
2. Other three inserted into the lateral sides of the
tendons of the Extensor digitorum longus of the
second, third, and fourth toes.
NERVE SUPPLY:
Deep peroneal nerve.
FUNCTION:
Extends the phalanges of the four toes.
THE PLANTAR MUSCLES OF THE FOOT:
The muscles of the sole of foot are conveniently
described in four layers from the inferior layer superiorly.
A) THE FIRST LAYER
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Abductor hallucis.
Flexor digitorum brevis.
Abductor digiti minimi.
B) THE SECOND LAYER
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Quadratus plantae
Lumbricals.
Flexor Digitorum Longus Tendon.
Flexor Hallucis longus Tendon.
C) THE THIRD LAYER
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Flexor hallucis brevis.
Adductor hallucis.
Flexor digiti minimi
brevis.
D) THE FOURTH LAYER:
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Dorsal interossei
Plantar interossei
Peroneus longus tendon.
Tibialis posterior tendon.
THE FIRST LAYER
ABDUCTOR HALLUCIS:
Medial border of the foot.
ORIGIN:
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Medial process of the tuberosity
of the Calcaneus.
Flexor Retinaculum.
INSERTION:
•
Tibial side of the base of the
proximal phalanx of the great
toe.
NERVE SUPPLY:
Medial Planter nerve.
ACTION: Flexes and abducts big toe; braces medial longitudinal arch
FLEXOR DIGITORUM BREVIS:
Middle of the Sole Of The Foot
ORIGIN:
•
Medial process of the tuberosity of
the Calcaneus.
INSERTION:

Four tendons to four lateral toes -

Sides of the middle phalanx about
its middle, tendons perforated by
those of the flexor digitorum
longus.
NERVE SUPPLY: Medial planter nerve.
ACTION: Flexes lateral four toes; braces medial and longitudinal lateral
arches
ABDUCTOR MINIMI DIGITI:
LATERAL BORDER OF THE FOOT:
ORIGIN:
•
Lateral process of the tuberosity of
the Calcaneus,
•
The forepart of the medial process of
calcaneum.
INSERTION:
•
Into the fibular side of the base of the
proximal phalanx of the fifth toe.
NERVE SUPPLY: Lateral Planter Nerve.
ACTION: Flexes and abducts big toe; braces lateral longitudinal arch.
B) THE SECOND LAYER
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Quadratus plantae
Lumbricals.
Flexor Digitorum Longus Tendon.
Flexor Hallucis longus Tendon.
QUADRATUS PLANTAE / FLEXOR
DIGITORUM ACCESSORIUS
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ORIGIN :arises by two heads:
•
Medial or larger head _muscular is
attached to the medial concave
surface of the Calcaneus.
•
Lateral head, flat and tendinous,
arises from the lateral border of the inferior surface of the Calcaneus,
•
End in a flattened band.
INSERTION:
•
Lateral margin and upper and under surfaces of the tendon of the
Flexor digitorum longus.
NERVE SUPPLY: Lateral plantar
nerve.
ACTION:
Assists flexor digitorum longus in
flexing lateral four toes.
LUMBRICALS:
ORIGIN:
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Four small muscles.
Arise from tendons of the Flexor
digitorum longus.
INSERTION:
•
Expansions of the tendons of the
Extensor digitorum longus on the
dorsal surfaces of the proximal
phalanges of lateral four toes.
NERVE SPPLY:
First lumbrical: Medial Plantar Nerve
Remainder: Lateral Plantar nerve
ACTION: Extends toes at Interphalangeal joint.
C) THE THIRD LAYER
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Flexor hallucis brevis.
Adductor hallucis.
Flexor digiti minimi brevis.
FLEXOR HALLUCIS BREVIS
ORIGIN:
•
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Cuboid bone
The contiguous portion of the
third cuneiform
From the prolongation of the
tendon of the Tibialis posterior
INSERTION:
•
Into the medial and lateral sides of the base of the proximal phalanx
of the great toe.
NERVE SUPPLY:
Medial plantar nerve.
ACTION: Flexes Metatarsophalangeal joint of big toe; supports medial
longitudinal arch.
ADDUCTOR HALLUCIS:
ORIGIN:
•
Arises by two heads—oblique and
transverse
OBLIQUE HEAD:
ORIGIN:
Arise by bases of the second, third,
and fourth metatarsal bones
INSERTED:
Lateral side of the base of the proximal phalanx of the great toe
TRANSVERSE HEAD:
•
Arises from the plantar metatarsophalangeal ligaments of the third,
fourth, and fifth toes and
INSERTION :
• lateral side of the base of the proximal phalanx of the great toe
NERVE SUPPLY
Deep branch lateral planter nerve
ACTION:
Flexes Metatarsophalangeal joint of big
toe; holds together metatarsal bones.
FLEXOR DIGITI MINIMI
BREVIS
ORIGIN:
•
Base of the fifth
metatarsal bone,
•
INSERTION:
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Lateral side of the
base of the proximal
phalanx of the fifth
toe
NERVE SUPPLY:
Lateral plantar nerve.
ACTION:
Flexes metatarsophalangeal joint of little toe.
D) THE FOURTH LAYER:
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Dorsal interossei
Plantar interossei
Peroneus longus tendon.
Tibialis posterior tendon.
PLANTAR INTEROSSEI:
•
Three in number.
ORIGIN:
•
The bases and medial sides of the
bodies of the third, fourth, and
fifth metatarsal bones
INSERTION:
• medial sides of the bases of the
proximal phalanges of the lateral
three toes
NERVE SUPPLY:
Lateral Planter nerve
ACTION:
Adduction of toes,
Flexes metatarsophalangeal joints and
extends Interphalangeal joint.
DORSAL INTEROSSEI:
•
Four in number.
ORIGIN:
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By Two heads from the adjacent sides of the metatarsal
bones
INSERTION:
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The bases of the proximal
phalanges.
The aponeurosis of the tendons of
the extensor digitorum longus.
NERVE
SUPPLY:
Lateral plantar nerve.
ACTION:
Adduction of toes; flexes
Metatarsophalangeal joints and extends
interphalaneal joints
References:
• Clinically oriented anatomy
• 6th edition
• KLM
• Ch 5 – lower limb
• Pgs. # 610-614
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