Intrinsic Foot Muscles Flashcards
What’s the (only) intrinsic foot muscle in the dorsum of the foot?
extensor digitorum brevis (we’re considering ext. hallucis brevis to be part of ext. dig. brev.)
What are the attachment pionts of extensor digitorum brevis?
S/P: anterior dorsal surface of the calcaneus
I/D: medial distal 4 phalanges (we’re considering ext. hallucis brevis to be part of ext. dig. brev.)
What’s the action of extensor digitorum brevis?
Extension of the medial 4 toes
How are abduction and adduction referenced when considering the foot?
Everything moving away/toward the 2nd toe (abd away; add toward)
How many muscular layers are there in the sole of the foot?
4
What are the muscles of the first layer in the sole of the foot?
- abductor hallucis
- flexor digitorum brevis
- abductor digiti minimi
What’s the action of abductor hallucis?
abduction of the 1st toe
What’s the action of flexor digitorum brevis?
flexion of 2nd-5th toes
What’s the action of abductor digiti minimi
abduction of the 5th toe
What are the muscles of the 2nd layer of the sole of the foot?
- quadratus plantae
- lumbricals
What’s the action of quadratus plantae
assists flexor digitorum longus in flexion of the lateral 4 digits
What are the tendons of the 2nd layer of the sole of the foot?
tendons of flexor hallucis longus and and flexor digitorum longus
What are the muscles of the 3rd layer of the sole of the foot?
- flexor hallucis brevis
- adductor hallucis
- flexor digiti minimi brevis
What’s the action of flexor hallucis brevis?
flexion of the 1st MTP joint
What’s the action of adductor hallucis and what does it help maintain?
- adducts 1st toe
- helps maintain transverse arch
What’s the action of flexor digiti minimi brevis?
flexion of the 5th MTP joint
What are the muscles of the fourth layer of the sole of the foot?
- dorsal interossei
- plantar interossei
What’s the action of dorsal interossei?
abduction of the 2nd-4th MTP joints (dorsal abduction)
What’s the action of plantar interossei
adduction of the 3rd-5th MTP joints (plantar adduction)
There are two sesamoid bones near the 1st phalanx of the foot. What muscle’s tendons adhere to these bones and what is the benefit served by the bones in these tendons?
- flexor hallucis brevis
- bones protect the tendons from pressure during standing and walking
