Foot Muscles Flashcards
The muscles acting on the foot can be divided into which two groups?
Extrinsic muscles
Intrinsic muscles
Where do the extrinsic muscles of the foot arise from?
What sorts of actions are they responsible for?
The anterior, lateral and posterior compartments of the leg
Dorsiflexion, eversion, plantarflexion and inversion
Where are the intrinsic muscles of the foot located?
What actions are they responsible for?
In the foot
Fine motor actions of the foot
The intrinsic muscles of the foot can be divided into those situated on the ___________ of the foot and those in the __________ of the foot
Dorsum
Sole
How many intrinsic muscles are there located in the dorsum of the foot?
2
Name the two muscles of the dorsal aspect of the foot
Extensor digitorum brevis
Extensor hallucis brevis
Both intrinsic muscles of the dorsum of the foot (extensor digitorum brevis and extensor hallucis brevis) are innervated by…
The deep fibular nerve
Where does the extensor digitorum brevis lie in relation to the extensor digitorum longus?
Lies deep to its tendon
Where does the extensor digitorum brevis originate and attach?
Originates - calcaneus, interosseous talocalcaneal ligament and the inferior extensor retinaculum
Attaches - long extensor tendons of the four lateral digits
What is the function of the extensor digitorum brevis?
Extends the lateral four toes at the metatarsophalangeal and interphalangeal joints
Which nerve innervates the extensor digitorum brevis?
Deep fibular nerve
Where is the extensor hallucis brevis located in relation to the extensor digitorum longus and extensor hallucis longus?
Medial to the extensor digitorum longus
Lateral to the extensor hallucis longus
Where does the extensor hallucis brevis originate and attach?
Originates - calcaneus, interosseous talocalcaneal ligament and the inferior extensor retinaculum
Attaches - base of the proximal phalanx of the big toe
What is the function of the extensor hallucis brevis?
Extends the big toe at the metatarsophalangeal joint
Which nerve innervates the extensor hallucis brevis?
Deep fibular nerve
How many intrinsic muscle are located in the sole of the foot?
10
How do the intrinsic muscles on the sole of the foot collectively function?
Individually function?
To stabilise arches of the foot
Control movement of individual digits
All the intrinsic muscles in the sole of the foot are innervated by either the…
Medial plantar nerve
Lateral plantar nerve
Both the medial and lateral plantar nerves are branches of the…
Tibial nerve
The intrinsic muscles of the plantar aspect of the foot can be arranged in…
4 layers (superficial to deep)
How many muscles are located in the first, most superficial layer of the plantar aspect of the foot?
Name them
3
Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi
The first three muscles (most superficial) on the plantar aspect of the foot are located immediately underneath the…
Plantar fascia
Where is the abductor hallucis located on the sole of the foot?
On the medial side
Where does the abductor hallucis originate and attach?
Originates - medial tubercle of the calcaneus, flexor retinaculum, plantar aponeurosis
Attaches - medial base of the proximal phalanx of the big toe
What is the action of the abductor hallucis?
Abducts and flexes the great toe
Which nerve innervates the abductor hallucis?
Medial plantar nerve
Where does the flexor digitorum brevis lie in the sole of the foot?
Lateral to the abductor hallucis
In the centre of the sole between the plantar aponeurosis and tendons of the flexor digitorum longus
List the intrinsic muscles of the sole of the foot (superficial layer) from medial to lateral
Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi
Where does the flexor digitorum brevis originate and attach?
Originates - medial tubercle of the calcaneus and plantar aponeurosis
Attaches - middle phalanges of the lateral 4 digits
What is the action of the flexor digitorum brevis?
Flexes the lateral four digits at the proximal interphalangeal joints
Which nerve innervates the flexor digitorum brevis?
Medial plantar nerve
On which aspect of the sole of the foot does the abductor digiti minimi lie?
Lateral aspect
Where does the abductor digiti minimi originate and attach?
Originates - medial and lateral tubercles of the calcaneus and plantar aponeurosis
Attaches - lateral base of the proximal phalanx of the 5th digit
Which nerve innervates the abductor digiti minimi?
Lateral plantar nerve
What is the action of the abductor digiti minimi?
Abducts and flexes the 5th digit
The second layer of the sole of the foot consists of how many intrinsic muscles?
Name them
2
Quadratus plantae
Lumbricals
Where is the quadratus plantae located in relation to the flexor digitorum longus tendons?
Superior to the tendons
What separates the quadratus plantae from the first layer of muscles in the sole of the foot?
Lateral plantar vessels and nerves
Where does the quadratus plantae originate and attach?
Originates - medial and lateral plantar surface of the calcaneus
Attaches - tendons of flexor digitorum longus
What is the action of the quadratus plantae?
Assists the flexor digitorum longus in flexing the lateral four digits
Which nerve innervates the quadratus plantae?
Lateral plantae nerve
How many lumbricals are there in the foot?
Where are they located relative to the tendon of their respective flexor digitorum longus?
4
Medial to the tendon
Where do the lumbricals originate and attach?
Originates - tendons of flexor digitorum longus
Attaches - extensor hoods of the lateral four digits
What is the action of the lumbricals?
Flexes at the metatarsophalangeal joints
Extends at the interphalangeal joints
Which nerve innervates the lumbricals?
Medial lumbrical - medial plantar nerve
Other 3 lumbricals - lateral plantar nerve
How many muscles are found in the 3rd layer of the intrinsic muscles on the plantar aspect of the foot?
Name them
3
Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis
What aspect of the foot is the flexor hallucis brevis located on?
Medial side of the foot
Where does the flexor hallucis brevis originate and attach?
Originates - plantar surfaces of the cuboid and lateral cuneiforms, tendon of the posterior tibialis tendon
Attaches - base of the proximal phalanx of the great toe
What is the action of the flexor hallucis brevis?
Flexes the proximal phalanx of the great toe at the metatarsophalangeal joint
Which nerve innervates the flexor hallucis brevis?
Medial plantar nerve
The adductor hallucis consist of which heads? Where is it located in relation to the flexor hallucis brevis?
2 heads - oblique and transverse
Laterally to the flexor hallucis brevis
Where does the oblique head of the adductor hallucis originate?
Where does the transverse head of the adductor hallucis originate?
Bases of the 2nd, 3rd and 4th metatarsals
Plantar ligaments of the metatarsophalangeal joints
Where do both heads of the adductor hallucis attach?
Lateral base of the proximal phalanx of the great toe
What is the action of the adductor hallucis?
Adducts the great toe
Assists in forming the transverse arch of the foot
Which nerve innervates the adductor hallucis?
Deep branch of the lateral plantar nerve
Where is the flexor digiti minimi brevis located?
On the lateral side of the foot underneath the metatarsal of the little toe
Where does the flexor digiti minimi brevis originate and attach?
Originates - base of the 5th metatarsal
Attaches - base of the proximal phalanx of the 5th digit
What is the action of the flexor digiti minimi brevis?
Flexes the proximal phalanx of the 5th digit
Which nerve innervates the flexor digiti minimi brevis?
Superficial branch of the lateral plantar nerve
Which 2 muscles exist in the 4th layer of the intrinsic muscles of the foot on the dorsal aspect?
Plantar interossei
Dorsal interossei
What type of muscles are the plantar interossei?
What type of muscles are the dorsal interossei?
Unipennate
Bipennate
How many plantar interossei are there? What are they located between?
How many dorsal interossei are there? What are they located in between?
3
Metatarsals
4
Metatarsals
The plantar interossei each arise from how many metatarsals?
1
The dorsal interossei each arise from how many metatarsals?
2
Where do the plantar interossei originate and attach?
Originates - medial side of metatarsals 3-5
Attaches - medial sides of phalanges 3-5
What is the function of the plantar interossei?
Adducts digits 3-5
Flexes the metatarsophalangeal joints
Which nerve innervates both the plantar and dorsal interossei?
Lateral plantar nerve
Where do the dorsal interossei originate and attach?
Originates - sides of metatarsals 1-5
Attaches - 1st muscle to the medial side of the proximal phalanx of the second digit. 2nd-4th to the lateral sides of the digits 2-4
What is the function of the dorsal interossei?
Abducts digits 2-4
Flexes metatarsophalangeal joints
How can the tearing of the extensor digitorum brevis be distinguished from a sprained ankle?
Torn muscle will produce a swelling anteromedial to the lateral malleolus (haematoma)
The medial plantar nerve can become compressed as it passes deep to the…
What can this cause?
Abductor hallucis
Aching, numbers and paresthesia on the medial sole of the foot
