Muscles of the Foot

Question 1

Dorsal aspect

Answer 1

Extensor digitorum brevis

Extensor hallucis brevis

Question 2

Extensor digitorum brevis

Answer 2

• Origin - calcaneus, interosseous talocalcaneal ligament and inferior extensor retinaculum
• Attachment - long extensor tendons of 4 lateral digits
• Actions - aids extensor digitorum longus in extending medial 4 toes at metatarsophalageal and interphalangeal joints
• Innervation - deep fibular nerve

Question 3

Extensor hallucis brevis

Answer 3

• Origin - calcaneus, interosseous talocalcaneal ligament and inferior extensor retinaculum
• Attachment - base of proximal phalanx of big toe
• Actions - aids extensor hallucis longus in extending big toes at metatarsophalangeal joint
• Innervation - deep fibular nerve

Question 4

Plantar aspect - first layer

Answer 4

Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi

Question 5

Plantar aspect - second layer

Answer 5

Quadratus plantae

Lumbricals

Question 6

Plantar aspect - third layer

Answer 6

Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis

Question 7

Plantar aspect - fourth layer

Answer 7

Plantar interossei

Dorsal interossei

Question 8

Contusion of extensor digitorum brevis

Answer 8

Results in haematoma

Swelling anteromedial to lateral malleolus

Question 9

Medial plantar nerve entrapment

Answer 9

Medial plantar nerve compressed and irritated as it passes deep to abductor hallucis muscle
Aching, numbness, paraesthesia on medial side of foot
Repetitive eversion of foot in sports such as gymnastics