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Myology

Myology of the

Foot

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Intrinsic Muscle of the Foot: OverviewDorsum of foot:

1. Extensor Digitorum Brevis: Extends toes 1 through 4

Plantar Surface:Layer 1 (Superficial): All originate on the calcaneus and insert into the toes

1. Abductor Hallucis: Abducts and flexes the great toe2. Flexor Digitorum Brevis: Flexes MP’s and PIP’s of the four lateral toes3. Abductor Digiti Minimi: Abducts and Flexes the 5th toe

Layer 2:1. Lumbricales: Same action as the hand2. Quadratus Plantae: Originates on the calcaneus and inserts the tendons of the flexor

digitorum longus. As a result it assists in the flexion of the four lateral toesLayer 3:

1. Flexor Hallucis Brevis: Flexes the great toe at the MP2. Adductor Hallucis: Adducts and flexes the great toe3. Flexor Digiti Minimi Brevis: Flexes the 5th toe at the MP

Layer 4: (Deepest)1. Dorsal Interossei: DAB and assists the lumbricals2. Plantar Interossei: PAD and assists the lumbricals

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Extensor Digitorum BrevisExtensor Hallucis Brevis

O: Dorsal surface of calcaneus

I: Top of toes 1 – 4

A: Extends toes 1-4

N: Deep peroneal nerve

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Plantar Surface of the Foot Layer 1

Abductor Hallucis Longus

Flexor Digitorum Brevis

Abductor Digiti Minimi

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Abductor Hallucis

O: Calcaneus

I: Medial side of great toe

A: Abducts great toe

N: Medial plantar nerve (branch

of tibial nerve)

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Flexor Digitorum Brevis

O: Calcaneus

I: Plantar surface of middle 3

phalanges of toes 2 - 5

A: Flexes toes at MP and PIP

joints

N: Medial plantar nerve (branch

of tibial nerve)

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Abductor Digiti Minimi

O: Calcaneus

I: Lateral side of the 5th toe

A: Abducts the 5th toe

N: Lateral plantar nerve (branch

of tibial nerve)

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Plantar Surface of the Foot Layer 2

Lumbricales

Quadratus Plantae

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Lumbricales

O: Tendons of the Flexor Digitorum

Longus

I: Tendons of the Extensor Digitorum

Longus

A: Flexes the MP’s and Extends the

DIP’s and PIP’s

N: Medial and Lateral plantar nerves

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Quadratus Plantae

O: Calcaneus

I: Tendons of the Flexor Digitorum

Longus

A: Flexes toes 2 – 5 at the MP, PIP,

and DIP joints

N: Lateral plantar nerve (branch

of tibial nerve)

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Plantar Surface of the Foot Layer 3

Flexor Hallucis Brevis

Adductor Hallucis

Flexor Digiti Minimi Brevis

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Flexor Hallucis Brevis

O: Tarsals (Cuboid and 3rd Cuneiform)

I: Base of the proximal phalange of the

great toe

A: Flexes the great toe at the MP joint

N: Medial plantar nerve

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Adductor Hallucis

O:

Oblique Head: tendon of the peroneus

longus and bases of 2 – 4th metatarsals.

Transverse Head: Plantar metatarso-

phalangeal ligaments

I: Lateral side of the base of the proximal phalange of the great toe

A: Adducts the great toe

N: Lateral plantar nerve

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Flexor Digiti Minimi Brevis

O: tendon of the peroneus longus and

the base of the 5th metatarsal.

I: Base of the proximal phalange of the

5th toe

A: Flexes the little toe at the MP joint

N: Lateral plantar nerve

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Plantar Surface of the Foot Layer 4

Dorsal Interossei

Plantar Interossei

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Dorsal Interossei

O: Each one arises from the adjacent

sides of two metatarsals.

I: Sides of the phalanges and the distal

tendons of the Extensor digitorum

longus.

A: Abducts the toes (DAB)

N: Lateral plantar nerve

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Plantar Interossei

O: Medial side of 3 – 5th metatarsals.

I: Sides of the phalanges and the

distal tendons of the Extensor

digitorum longus.

A: Adducts the toes (PAD)

N: Lateral plantar nerve