Foot Muscles

Question 1

Extensor digitorum brevis

Answer 1

Origin: Dorsal surface calcaneus
Insertion: Long extensor tendons of digits 2-4
Action: extension toes at MTP joints 2-4, extension toes at PIP joints 2-4
Innervation: Deep fibular nerve L5, S1

Question 2

Extensor hallucis brevis

Answer 2

Origin: Dorsal surface calcaneus
Insertion: base of 1st proximal phalanx
Action: Extension great toe at MTP joint
Innervation: Deep fibular nerve L5, S1

Question 3

Abductor hallucis

Answer 3

Origin: medial calcaneus
Insertion: Base of 1st proximal phalanx
Action: abduction great toe at MTP, Flexion great toe at MTP
Innervation: Medial plantar nerve S2, S3

Question 4

Flexor digitorum brevis

Answer 4

Origin: calcaneal tuberosity
Insertion: middle phalanges 2-5
Action: flexion toes at MTP and PIP joints 2-5
Innervation: Medial plantar nerve S2, S3

Question 5

Abductor digiti minimi

Answer 5

Origin: lateral calcaneal tuberosity
Insertion: base of 5th proximal phalanx
Action: abduction of 5th toe at MTP, flexion of 5th toe at MTP
Innervation: lateral plantar nerve S2, S3

Question 6

Quadratus plantae

Answer 6

Origin: calcaneal tuberosity
Insertion: lateral border of flexor digitorum longus tendon
Action: redirects and augments pull of flexor digitorum longus
Innervation: lateral plantar nerve S2, S3

Question 7

Lumbricals

Answer 7

Origin: tendons of flexor digitorum longus
Insertion: dorsal aponeuroses of digits 2-5
Action: flexion toes at MTP 2-5, extension toes at PIP and DIP 2-5
Innervation: 1st: medial plantar nerve 2nd-4th: lateral plantar nerve S2, S3

Question 8

Flexor hallucis brevis

Answer 8

Origin: tendon of Tibialis posterior, medial head: medial cuneiform, lateral head: intermediate, lateral cuneiforms, cuboid
Insertion: base of 1st proximal phalanx
Action: flexion of toes at 1st MTP
Innervation: medial: medial plantar nerve lateral: lateral plantar nerve S2, S3

Question 9

Adductor hallucis

Answer 9

Origin: oblique head: base of metatarsals 2-4, cuboid, lateral cuneiform Transverse head: deep transverse metatarsal ligaments of MTP 3-5
Insertion: base of 1st proximal phalanx
Action: oblique: adduction great toe at MTP, flexion great toe at MTP
Transverse: adduction great toe at MTP, support transverse arch
Innervation: lateral plantar nerve S2, S3

Question 10

Flexor digiti minimi brevis

Answer 10

Origin: base of 5th metatarsal
Insertion: base of 5th proximal phalanx
Action: Flexion 5th toe at MTP
Innervation: lateral plantar nerve S2, S3

Question 11

Plantar interossei 1-3

Answer 11

Origin: Medial border of metatarsals 3-5
Insertion: medial base of proximal phalanges 3-5
Action: adduction toes 3-5 at MTP
Innervation: lateral plantar nerve S2, S3

Question 12

Dorsal interossei 1-4

Answer 12

Origin: two heads from opposing sides of metatarsals 1-5
Insertion: First: medial base of 2nd proximal phalanx
2-4: lateral base of proximal phalanges 2-4
Action: Abduct toes 2-4 at MTP
Innervation: lateral plantar nerve S2, S3