FOOT - muscles

Question 0

extensor digitorum brevis

Answer 0

dorsum of foot (bump often mistaken for swelling)
Origin: dorsal surface of calcaneus
Insertion: toes 2-4 via EDL tendons
action: extends toes 2-4
nerve: deep peroneal, L4-5, S1
partner supine w/feet off end of table - from lateral malleolus move inferior and toward 5th toe - partner extend toes against resistance

Question 1

muscles

Answer 1

called ‘little soldiers’ because the bear weight of entire body
walking - pressure increased 2x
running - pressure increased 5x
3 arches to connect 3 main points of contact - calcaneus, 1st & 5th metatarsals
work together to help distribute forces through the body
arches also help with uneven terrain

Question 2

flexor digitorum brevis

Answer 2

Origin: medial process of calcaneus & plantar aponeurosis
Insertion: middle phalanges of toes 2-5
action: flexes middle phalanges of toes 2-5
nerve: tibial, L4-5, S1
partner supine w/feet off end of table - find plantar aspect of heel & toes 2-5 - palpate into medial arch and move finger medially-laterally while partner flexes/relaxes toes

Question 3

abductor hallucis

Answer 3

Origin: medial process of calcaneus and plantar aponeurosis
Insertion: proximal phalanx of great toe (medially) & media sesamoid
action: abducts great toe & assists flexion of MP joint of 1st toe
nerve: tibial, L4-5, S1
partner supine w/feet off end table - from medial surface of heel & medial surface of 1st toe - partner abduct toe - note strength/density of muscle

Question 4

abductor digiti minimi

Answer 4

Origin: lateral process of calcaneus & plantar aponeurosis
Insertion: proximal phalanx of 5th toe (lateral surface)
action: flexes the 5th toe & assists to abduct MP joint of 5th toe
nerve: tibial, S1-2
partner supine with feet off end of table - find plantar surface of heel & lateral aspect of 5th toe - note thick band of tissue when partner abducts/flexes 5th toe

Question 5

extensor hallucis brevis

Answer 5

from dorsal surface of calcaneus across top of foot to 1st toe
extends the MP joint of 1st toe

Question 6

flexor hallucis brevis

Answer 6

from plantar aspect of cuboid & lateral cuneiform to medial & lateral surfaces of base of PP 1st toe
flexes MP joint of 1st toe

Question 7

adductor hallucis

Answer 7

from plantar aspect of bases of metatarsals 2-4 & plantar ligament of 3-5 MP joints to lateral aspect of PP of 1st toe
adducts the 1st toe & assist to maintain transverse arch of foot & flex 1st toe

Question 8

flexor digiti minimi brevis

Answer 8

from plantar aspect of base of 5th metatarsal to base of PP of 5th toe
flexes MP joint of 5th toe

Question 9

quadratus plantae

Answer 9

from medial & lateral sides of calcaneus to posterior lateral aspect of FDL tendon
assists to flex toes 2-5

Question 10

plantar interossei

Answer 10

medial surfaces of 3-5 metatarsals to medial surfaces of PP of toes 3-5
adducts toes 3-5 at MP joint & flexes toes 3-5 at MP joint

Question 11

dorsal interossei

Answer 11

from adjacent surfaces of all metatarsals to medial surface of 1st toe and lateral surfaces of PP for toes 2-4
abducts toes 2-4 at MP joint & flexes toes 2-4 at MP joint

Question 12

lumbricals

Answer 12

from tendons of FDL to bases of PP of toes 2-5 & EDL tendons

flexes PP of toes 2-5 at MP joints & extends middle & distal phalanges of toes 2-5 at IP joint

Question 13

gastrocnemius

Answer 13

part of the triceps surae (gastroc-soleus as it attaches via Achilles’ tendon into calcaneus)
2 heads
crosses 2 joints - knee & ankle
Origin: posterior condyles of femur
Insertion: calcaneus
action: flexes the knee & plantar flexes the ankle
nerve : tibial, S1-2
palpate while partner rises onto toes - feel both heads
partner prone, knee flexed - then extended - look for difference in strength

Question 14

soleus

Answer 14

deep to gastroc & surrounds it laterally & posteriorly
called ‘second heart’ - its contractions help return blood from leg to heart
Origin: soleal line, posterior surface of tibia & fibula
Insertion: calcaneus
action: plantar flexes the ankle
nerve: tibial, L5, S1-2
palpate while partner tries to raise onto toes

Question 15

plantaris

Answer 15

longest tendon in body
small muscle belly lies at oblique angle along popliteal space between heads of gstroc
Origin: lateral supracondylar line of femur
Insertion: calcaneus
action: weak plantar flexor & knee flexor
nerve: tibial, L4-5, S1,2
palpate partner prone, knee flexed - from head of fibula move thumb medially into popliteal space between gastroc heads then sink deeper & feel for band going at angle from lateral to medial
similar to palmaris longus in forearm (absent in 10% pop)

Question 16

popliteus

Answer 16

located in popliteal space
deepest muscle of posterior knee (below gastroc & plantaris)
Origin: lateral condyle of femur
Insertion: proximal posterior aspect of tibia
action: weak knee flexor, unlocks the knee
partner prone with knee flexed - find tibial tuberosity & slide medially to posterior aspect, push gastroc & soleus aside

Question 17

peroneus longus

Answer 17

(fibularis longus)
very slender, on lateral side of fibula
lie between extensor diditorum longus & soleus
Origin: head of fibula & proximal 2/3 of lateral fibula
Insertion: base of 1st metatarsal & medial cuneiform (plantar aspect)
action: everts foot & assists plantar flexion of ankle (talocrural joint)
nerve: superficial peroneal, L4-5, S1
partner laying on side - finger at head of fibula & lateral malleolus - feel what happens when foot everted - follow tendon to base of 5th & then under foot to base of 1st

Question 18

peoneus brevis

Answer 18

(fibularis brevis)
very slender, on lateral side of fibula
lie between extensor diditorum longus & soleus
Origin: distal 2/3 lateral fibula
Insertion: tuberosity of 5th metatarsal laterally
action: everts foot & assists plantar flexion of ankle (talocrural joint)
nerve: superficial peroneal, L4-5, S1
partner laying on side - finger at head of fibula & lateral malleolus - feel what happens when foot everted - follow tendon to base of 5th & then under foot to base of 1st

Question 19

tibalis anterior

Answer 19

just lateral to shaft of tibia
Origin: lateral condyle of tibia & proximal lateral surface of tibial and interosseus membrane
Insertion: medial cuneiform & base of 1st metatarsal
action: invert foot & dorsiflex ankle
nerve: deep peroneal, L4-5, S1
partner supine - from shaft of tibia slide laterally and partner dorsiflex ankle - follow down into foot

Question 20

extensor digitorum longus

Answer 20

between tibialis anterior & peroneals
able to palpate on dorsum of foot
Origin: lateral condyle of tibia & proximal anterior shaft of fibula & interosseus membrane
Insertion: middle & distal phalanges of toes 2-5
action: dorsiflexion, eversion of ankle & extension of toes 2-5

Question 21

extensor hallucis longus

Answer 21

muscle belly deep, can find distal tendon
Origin: middle anterior surface of fibula & interosseus membrane
Insertion: distal phalax of great toe
action: extends first toe, dorsiflexes ankle, inverts foot
nerve: deep peroneal, L4-5, S1
partner supine, extend great toe - follow tendon towards ankle & see how it slips under EDL & TA tendone

Question 22

tibalis posterior

Answer 22

(part of TOM Dick AN Harry)
virtually inaccessible except medial distal tibia
Origin: proximal posterior shafts of tibia & fibula & interosseus membrane
Insertion: all 5 tarsals & bases of 2-4 metatarsals
action: inverts foot & plantarflexes ankle
nerve: tibial, L4,5, S1

Question 23

flexor digitorum longus

Answer 23

(part of Tom DICK AN Harry)
Origin: middle posterior surface of tibia
Insertion:distal phalanges of toes 2-5
action: flexes toes 2-5, weak plantar flexor of ankle, inverts foot
nerve: tibial L5, S1,2

Question 24

floexor hallucis longus

Answer 24

(part of Tom Dick AN HARRY)
Origin: middle half of posterior fibula
Insertion: distal phalanx of great toe on plantar aspect of foot
action: flexes great toe, weak plantar flexor of ankle, invert foot
nerve: tibial, L5, S1-2
all flexors partner supine/on side - palpate medial malleolus & go up and down that area
TP is the most anterior of tendons - instruct partner to wiggle toes & note movement in area
find tibial artery (posterior tibial artery) - used to determine proper circulation to foot, hard to find