Lower Limb Muscles of the Foot Flashcards
What are the two groups of foot muscles?
Extrinsic - from anterior, posterior, and lateral compartments and responsible for eversion, inversion, plantarflexion and dorsiflexion of the foot.
Intrinsic - within the foot and responsible for fine motor actions of the foots, like movement of individual digits.
What are the intrinsic muscles of the dorsum of the foot?
Extensor digitorum brevis and extensor hallucis brevis.
What are the proximal attachments of the extensor digitorum brevis?
Calcaneus, interosseous talocalcaneal ligament, stem of inferior extensor retinaculum.
What are the distal attachments of the extensor digitorum brevis?
Long extensor tendons of four medial digits - toes 2-4.
What is the extensor digitorum brevis innervated by?
Deep fibular nerve (L5, S1).
What is the arterial supply to the extensor digitorum brevis?
Dorsalis pedis artery.
What is the action of the extensor digitorum brevis?
Aids the extensor digitorum longus in extending the four medial toes at the metatarsophalangeal and interphalangeal joints.
What are the proximal attachments of the extensory hallucis brevis?
Calcaneus, interosseous talocalcaneal ligament, stem of inferior extensor retinaculum.
What are the distal attachments of the extensory hallucis brevis?
Dorsal aspet of base of proximal phalanx of great toe.
What is the extensory hallucis brevis innervated by?
Deep fibular nerve (L5, S1).
What is the arterial supply to the extensory hallucis brevis?
Dorsalis pedis artery
What is the action of the extensory hallucis brevis?
Aids the extensor hallucis longus in extending the great toe at the metatarsophalangeal joint.
How many intrinsic muscles are there in the sole of the foot?
10, divided into four layers (superficial to deep).
What is the overall function of the intrinsic muscles in the sole of the foot?
To stabilise the arches of the foot, and individually control movement of the digits.
What are the four layers of intrinsic muscles in the sole of the foot?
1st layer (most superficial): abductor hallucis, flexor digitorum brevis, abductor digiti minimi.
2nd layer: quadratus plantae, lumbricals.
3rd layer: flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis.
4th layer: plantar interossei (three muscles), dorsal interossei (four muscles).
What is the proximal attachment of the abductor hallucis?
Medial tubercle of tuberosity of calcaneus, flexor retinaculum, plantar aponeurosis.
What is the distal attachment of the abductor hallucis?
Medial side of base of proximal phalanx of 1st digit.
What is the abductor hallucis innervated by?
Medial plantar nerve (S2, S3).
What is the arterial supply of the abductor hallucis?
Medial plantar artery.
What is the action of the abductor hallucis?
Abducts and flexes 1st digit.
What is the proximal attachment of the flexor digitorum brevis?
Medial tubercle of tuberosity of calcaneus, plantar aponeurosis, intermuscular septa.
What is the distal attachment of the flexor digitorum brevis?
Both sides of middle phalanges of lateral four digits.
What is the flexor digitorum brevis innervated by?
Medial plantar nerve (S2, S3).
What is the arterial supply of the flexor digitorum brevis?
Deep branch of medial plantar artery, lateral plantar artery.
What is the action of the flexor digitorum brevis?
Flexes lateral four digits.
What is the proximal attachment of the abductor digiti minimi?
Medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, intermuscular septa.
What is the distal attachment of the abductor digiti minimi?
Lateral side of base of proximal phalanx of 5th digit.
What is the abductor digiti minimi innervated by?
Lateral plantar nerve (S2, S3).
What is the arterial supply of the abductor digiti minimi?
Lateral plantar artery.
What is the action of the abductor digiti minimi?
Abducts and flexes little toe.
What is the proximal attachment of the quadratus plantae?
Medial surface and lateral margin of plantar surface of calcaneus.
What is the distal attachment of the quadratus plantae?
Posterolateral margin of tendon of flexor digitorum longus.
What is the quadratus plantae innervated by?
Lateral plantar nerve (S2, S3).
What is the arterial supply of the quadratus plantae?
Lateral plantar artery.
What is the action of the quadratus plantae?
Assists flexor digitorum longus in flexing lateral four digits.
What is the proximal attachment of the lumbricals?
Tendons of flexor digitorum longus.
What is the proximal attachment of the lumbricals?
Medial aspect of expansion over lateral four digits.
What are the lumbricals innervated by?
Medial one - medial plantar nerve (S2, S3).
Lateral three - lateral plantar nerve (S2, S3).
What is the arterial supply of the lumbricals?
Superficial branch of medial plantar artery, plantar metatarsal arteries.
What is the action of the lumbricals?
Flex proximal phalanges, extend middle and distal phalanges of lateral four digits.
What are the proximal attachments of the flexor hallucis brevis?
Plantar surfaces of cuboid and lateral cuneiforms.
What are the distal attachments of the flexor hallucis brevis?
Both sides of base and proximal phalanx of 1st digit.
What is the flexor hallucis brevis innervated by?
Medial plantar nerve (S2, S3).
What is the arterial supply to the flexor hallucis brevis?
Deep branch of the medial plantar nerve.
What is the action of the flexor hallucis brevis?
Flexes proximal phalanx of 1st digit.
What are the proximal attachments of the adductor hallucis?
Oblique head - bases of metatarsasl 2-4.
Transverse head - plantar ligaments of metatarsophalangeal joints.
What are the distal attachments of the adductor hallucis?
Tendons of both heads attach to lateral side of base of proximal phalanx of 1st digit.
What is the adductor hallucis innervated by?
Deep branch of lateral plantar nerve (S2, S3).
What is the arterial supply to the adductor hallucis?
Deep plantar arch and plantar metatarsal arteries.
What is the action of the adductor hallucis?
Adduct 1st digit, assists in transverse arch of foot by metatarsals medially.
What are the proximal attachments of the flexor digiti minimi brevis?
Base of 5th metatarsal.
What are the distal attachments of the flexor digiti minimi brevis?
Base of proximal phalanx of 5th digit.
What is the flexor digiti minimi brevis innervated by?
Superficial branch of lateral plantar nerve (S2, S3).
What is the arterial supply to the flexor digiti minimi brevis?
Lateral plantar artery.
What is the action of the flexor digiti minimi brevis?
Flexes prxoimal phalanx of 5th digit, thereby assisting with its flexion.
What are the proximal attachments of the plantar interossei?
Plantar aspect of medial sides of shafts of metatarsals 3-5.
What are the distal attachments of the plantar interossei?
Medial side of bases of phalanges of 3rd-5th digits.
What is the plantar interossei innervated by?
Lateral plantar nerve (S2, S3).
What is the arterial supply of the plantar interossei?
Plantar metatarsal arteries.
What is the action of the plantar interossei?
Adduct digits 3-5 and flex metatarsophalangeal joints.
What are the proximal attachments of the dorsal interossei?
Adjacent sides of shaft of metatarsals 1-5.
What are the distal attachments of the dorsal interossei?
1st - medial side of proximal phalanx of 2nd digit.
2nd-4th: lateral sides of 2nd-4th digits.
What is the dorsal interossei innervated by?
Lateral plantar nerve (S2, S3).
What is the arterial supply of the dorsal interossei?
Dorsal metatarsal arteries.
What is the action of the dorsal interossei?
Abduct digits 2-4 and flex metatarsophalangeal joints.
What is contusion of extensor digitorum brevis?
Tearing of the extensor digitorum brevis muscle fibres that results in haematoma.
What is the characteristic sign of contusion of extensor digitorum brevis?
Swelling anteromedial to lateral malleolus.
What is medial plantar nerve entrapment?
Medial plantar nerve become compressed and irritated as it passes deep to the abductor hallucis muscle.
What are the symptoms of medial plantar nerve entrapment?
Aching, numbness, paraesthesia on medial side of sole of the foot.
What can cause medial plantar nerve entrapment?
Repetitive eversion of the foot, occurs in some sports like gymnastics.
