Foot Muscles Flashcards
Which muscles are in the dorsum of the foot?
Extensor hallucis brevis and extensor digitorum brevis
Which nerve innervates the muscles in the dorsum of the foot?
Deep fibular N
What are the attachment sites for extensor hallucis brevis?
O: common origin with extensor digitorum brevis
I: dorsal aspect of base of 1st proximal phalanx
What is the action of the extensor hallucis brevis muscle?
Extend the hallux at the metatarsophalangeal joint
What are the attachment sites for the extensor digitorum brevis muscle?
O: superolateral aspect of calcaneus and interosseous talocalcaneal L
I: lateral aspect of extensor digitorum longus tendon
What is the action of the extensor digitorum brevis muscle?
Extend digits 2-4
Which muscles are in the first layer of plantar muscles?
Abductor hallucis, flexor digitorum brevis and abductor digiti minimi
What is the common origin site for layer 1 plantar muscles (abductor hallucis, FDB, and abductor digiti minimi)?
Calcaneal tuberosity
What is the insertion site for abductor hallucis muscle?
Medial aspect of the base of 1st proximal phalanx
What is the action of abductor hallucis?
Abduct and flex the hallux
What is the insertion site for flexor digitorum brevis?
2nd-5th digits (intermediate phalanges)
What is the action of flexor digitorum brevis?
Flex digits 2-5
What is the insertion site for abductor digiti minimi?
Lateral aspect of the base of 5th proximal phalanx
What is the action of the abductor digiti minimi muscle?
Abduct and flex 5th digit
Which muscles are located in the second layer of plantar muscles?
Quadratus plantae and lumbricals
What are the attachment sites for the quadratus plantae muscle?
O: plantar surface of the calcaneus
I: lateral aspect of FDL tendon
What is the action of the quadratus plantae muscle?
Assist FDL in flexing digits 2-5
What are the attachment sites for the lumbrical muscles?
O: FDL tendon
I: medial proximal phalanx of digits 2-5 and medial aspects of digital expansion on digits 2-5
What is the action of the lumbrical muscles?
Flex metatarsophalangeal joints, extend proximal and distal interphalangeal joints
Which muscles are located in the 3rd layer of plantar muscles?
Flexor hallucis brevis, flexor digiti minimi and adductor hallucis
What are the attachment sites for flexor hallucis brevis?
O: plantar surface of cuboid and lateral cuneiform
I: base of 1st proximal phalanx
What is the action of the flexor hallucis brevis muscle?
Flex 1st proximal phalanx
What are the attachment sites for flexor digiti minimi brevis?
O: base of 5th metatarsal
I: base of 5th proximal phalanx
What is the action of the flexor digiti minimi brevis muscle?
Flex proximal phalanx of 5th digit
What are the attachment sites for adductor hallucis?
Oblique head: bases of 2nd-4th metatarsals
Transverse head: plantar metatarsophalangeal L
I: lateral aspect of the base of 1st proximal phalanx
What is adductor hallucis’s action?
Adduct hallux
Which muscles are located in the 4th plantar muscle layer?
Dorsal and plantar interossei
What are the attachment sites for dorsal interossei muscles?
O: adjacent edges and bases of 1st-5th metatarsal
1st inserts on medial aspect of 2nd proximal phalanx
2-4 insert on lateral aspect of bases of 2nd, 3rd and 4th proximal phalanges
What is the action of the dorsal interossei muscles?
Abduct digits 2-4 (DAB)
Flex MP joint
What are the attachment sites for plantar interossei muscles?
O: medial aspects and bases of of 3rd-5th metatarsals
I: medial aspect of bases of 3rd, 4th and 5th proximal phalanges
What is the action of plantar interossei muscles?
Adduct digits 3-5 (PAD)
Flex MP joint
How many dorsal interossei muscles are there?
4
How many plantar interossei muscles are there?
3
Which tendons are present in the 4th plantar muscle layer?
Fibularis longus and tibialis posterior tendons
What is a unique feature of the flexor hallucis brevis muscle found in the 3rd layer?
It’s tendons have sesamoid bones that protect the first metatarsal head and tendon of FHL when standing and walking
Which tendons are found in the second layer of plantar muscles?
Flexor hallucis longus and flexor digitorum longus tendons
What role do muscles of the sole of the foot (plantar muscles) play?
Help maintain foot arches and our ability to stand on uneven ground
Considered to be synergists
