Intrinsic Muscles Of The Foot

Question 1

Extensor digitorum brevis

Answer 1

Intrinsic muscle foot dorsal aspect
Origin: superolateral surface of the calcaneus
Insertion: lateral sides of the tendons of extensor digitorum longus of toes II to IV
Innervation: deep fibular nerve S1 S2
Function: extension of toes II to IV

Question 2

Extensor Hallucis brevis

Answer 2

Intrinsic muscle foot dorsal aspect
Origin: superolateral surface of calcaneus
Insertion: base of proximal phalanx of great toe
Innervation: deep fibular nerve S1 S2
Function: extension of metatarsophalangeal joint of great toe

Question 3

Abductor hallucis

Answer 3

1st layer sole of foot
Origin: medial process of calcaneal tuberosity
Insertion: medial side of base of proximal phalanx of great toe
Innervation: medial plantar nerve from the tibial nerve S1 S2 S3
Function: abducts and flexes great toe at metatarsophalangeal joint

Question 4

Flexor digitorum brevis

Answer 4

1st layer sole of foot
Origin: medial process of calcaneal tuberosity and plantar aponeurosis
Insertion: sides of plantar surface of middle phalanges of lateral 4 toes
Innervation: medial plantar nerve from the tibial nerve S1 S2 S3
Function: flexes lateral 4 toes at proximal interphalangeal joint

Question 5

Abductor digiti minimi

Answer 5

1st layer muscles sole of foot
Origin: lateral and medial processes of calcaneal tuberosity and band of connective tissue connecting calcaneus with base of metatarsal V
Insertion: lateral side of base of proximal phalanx of little toe
Innervation: lateral plantar nerve from tibial nerve S1 S2 S3
Function: abducts little toe at metatarsophalangeal joint

Question 6

Quadratus plantae

Answer 6

2nd layer sole of foot
Origin: medial surface of calcaneus and lateral process of calcaneal tuberosity
Insertion: lateral side of tendon of flexor digitorum longus in proximal sole of the foot
Innervation: lateral plantar nerve form tibial nerve S1 S2 S3
Function: assists flexor digitorum longus tendon in flexing toes II to V

Question 7

Lumbricals

Answer 7

2nd layer sole of foot
Origin: First lumbrical- medial side of tendon of flexor digitorum longus associated with toe II; second, third and fourth lumbricals - adjacent surfaces of adjacent tendons of flexor digitorum longus
Insertion: medial free margins of extensor hoods of toes II to V
Innervation: first lumbrical- medial plantar nerve from tibial nerve; second, third and fourth lumbricals- lateral plantar nerve from the tibial nerve S2 S3
Function: flexion of metatarsophalangeal joint and extension of interphalangeal joint

Question 8

Flexor hallucis brevis

Answer 8

3rd layer sole of foot
Origin: plantar surface of cuboid and lateral cuneiform, tendon of Tibialis posterior
Insertion: lateral and medial sides of base of proximal phalanx of the great toe
Innervation: medial plantar nerve From tibial nerve S1 S2
Function: flexes metatarsophalangeal joint of the great toe

Question 9

Adductor hallucis

Answer 9

3rd layer sole of foot
Origin: Transverse head- ligaments associated with metatarsophalangeal joints of lateral three toes. Oblique head- bases of metatarsals II to IV and from sheath covering fibularis longus
Insertion: lateral side of base of proximal phalanx of great toe
Innervation: lateral plantar nerve from tibial nerve S2 S3
Function: adducts great toe at metatarsophalangeal joint

Question 10

Flexor digiti minimi brevis

Answer 10

3rd layer sole of foot
Origins: base of metatarsal V and related sheath of fibularis longus tendon
Insertion: lateral side of base of proximal phalanx of little toe
Innervation: lateral plantar nerve from tibial nerve S2 S3
Function: flexes little toe at metatarsophalangeal joint

Question 11

Dorsal interossei

Answer 11

4th layer sole of foot
Origin: sides of adjacent metatarsals
Insertion: extensor hoods and bases of proximal phalanges of toes II to IV
Innervation: lateral plantar nerve from tibial nerve; first and second dorsal interossei also innervated by deep fibular nerve S2 S3
Function: abduction of toes II to IV at metatarsophalangeal joints; resist extension of metatarsophalangeal joints and flexion of interphalangeal joints

Question 12

Plantar interossei

Answer 12

4th layer sole of foot
Origin: medial sides of metatarsals of toes III to V
Insertion: extensor hoods and bases of proximal phalanges of toes III to V
Innervation: lateral plantar nerve from tibial nerve S2 S3
Function: Adduction of toes III to V at metatarsophalangeal joints; resists extension of the metatarsophalangeal joints and flexion of the interphalangeal joints

Question 13

Medial collateral ligament/ deltoid ligament

Answer 13

Tibionavicular fibres
Tibiocalcaneal fibres
Anterior tibiotalar fibres
Posterior tibiotalar fibres

Question 14

Lateral collateral ligament

Answer 14

Anterior talofibular ligament
Posterior talofibular
Calcaneofibular