Muscles of Foot

Question 1

Abductor Hallucis

Answer 1

1st layer

O: Medial tubercle of calcaneus, flexor retinaculum, plantar aponeurosis

I: Medial side of base of proximal phalanx of 1st digit

A: Abducts and flexes big toe

I: Medial plantar n.

Question 2

Flexor Digitorum Brevis

Answer 2

1st layer

O: Medial tubercle of calcaneus, plantar aponeurosis

I: Both sides of middle phalanges of toes 2–5

A: Flexes toes 2–5 at PIP joints

I: Medial plantar n.

Question 3

Abductor Digiti Minimi

Answer 3

1st layer

O; Medial and lateral tubercles of calcaneus, plantar aponeurosis

I: Lateral side of base of proximal phalanx of 5th digit

A: Abducts and flexes 5th toe

I: Lateral plantar n.

Question 4

Quadratus Plantae

Answer 4

2nd layer

O: Medial and lateral sides of plantar surface of calcaneus

I: Posterolateral margin of FDL tendon

A: Assists FDL in flexing toes

I: Lateral plantar n.

Question 5

Lumbricals

Answer 5

2nd layer

O: Tendons of FDL

I: Medial aspect of extensor expansion over toes 2–5

A: Flex MTPs, extend IPs

I: 1st: Medial plantar
2–4: Lateral plantar

Question 6

Flexor Hallucis Brevis

Answer 6

3rd layer

O: Plantar surface of cuboid and lateral cuneiform

I: Both sides of base of proximal phalanx of 1st digit (via sesamoids)

A: Flexes big toe

I: Medial plantar n.

Question 7

Adductor Hallucis

Answer 7

3rd layer

O: Oblique head: Bases of metatarsals 2–4
Transverse head: Plantar ligaments of MTP joints 3–5

I: Lateral side of base of proximal phalanx of 1st digit

A: Adducts big toe

I: Lateral plantar n.

Question 8

Flexor Digiti Minimi Brevis

Answer 8

3rd layer

O: Base of 5th metatarsal

I: Base of proximal phalanx of 5th digit

A: Flexes 5th toe

I: Lateral plantar n.

Question 9

Dorsal Interossei (4)

Answer 9

4th layer

O: Adjacent sides of metatarsals 1–5

I: 1st: medial side of proximal phalanx of 2nd digit
2nd–4th: lateral sides of proximal phalanges of digits 2–4

A: Abduct toes 2–4, flex MTPs

I: Lateral plantar n.

Question 10

Plantar Interossei (3)

Answer 10

4th layer

O: Medial sides of metatarsals 3–5

I: Medial sides of bases of proximal phalanges of digits 3–5

A: Adduct toes 3–5, flex MTPs

I: Lateral plantar n.