L18: Musculo-neuro-vascular systems of lateral leg and foot Flashcards
lateral compartment of leg; muscles [2], nerve
- fibularis [peroneus] longus
- fibularis [peroneus] brevis
nerve: superficial fibular [peroneal] nerve
lateral compartment of leg actions
principally evertors of foot
especially active during plantarflexion
- walking on toes
- pushing off with great toe
fibularis [peroneus] longus; origin
head and superior two thirds of lateral surface of fibula
fibularis [peroneus] longus; insertion
base of 1st metatarsal and medial cuneiform
fibularis [peroneus] longus; innervation + actions
innervation: superficial fibular [peroneal] nerve
action: eversion of foot and weak ankle plantarflexion
course of tendon of fibularis [peroneus] longus:
- swings under the foot to cross the sole of foot and insert into the base of the 1st metatarsal and medial cuneiform
- acts as a stirrup to support the arches of the foot
arches of foot formed by:
tarsal and metatarsal bones
Fibularis (peroneus) brevis; origin
lies deep to fibularis longus
origin: lower two thirds of lateral surface of fibula
Fibularis (peroneus) brevis; insertion
dorsal surface of tuberosity on lateral side of base of 5th metatarsal
Fibularis (peroneus) brevis; innervation + action
innervation: superficial fibular [peroneal] nerve
action: eversion of foot and weak ankle plantarflexion
lateral compartment nerves:
superficial fibular [peroneal] nerve
- terminal branch of common fibular nerve
- continues as cutaneous nerve, supplying skin on:
- distal anterior surface of leg
- most of dorsum of foot
lateral compartment blood vessels
- does not contain a major artery
- perforating branch arteries and veins
- perforating branches of anterior tibial artery
- perforating branches of fibular artery
bones of the foot
tarsals : talus, calcaneus, navicular, medial/intermediate/lateral cuneiform, cuboid
metatarsals
phalanges
joints of foot
ankle [talocrural] joint
joints of foot:
- subtalar
- transverse tarsal joint : talocalcaneonavicular, calcaneocuboid
- intertarsal joints
- tarsometatarsal joints
- metatarsophalangeal joints
- interphalangeal joints
movements of metatarsophalangeal joints:
flexion
extension
abduction
adduction
movements of interphalangeal joints:
flexion
extension
foot: deep fascia
- dorsal fascia continuous with inferior extensor retinaculum
- plantar fascia:
- thick central part: plantar aponeurosis
- weaker medial and lateral parts
- 3 compartments
- medial compartment
- central compartment
- lateral compartment
extrinsic muscles
extrinsic muscles from compartments of leg (anterior, lateral and posterior leg compartments)
- plantarflexion and dorsiflexion
- inversion and eversion
intrinsic muscles
intrinsic muscles originate an insert in the foot
20 muscles
- dorsum of foot [2]
- sole of foot (plantar) [14, 4 muscle layers]
- intermediate (4 dorsal interossei)
important in:
- propulsion of foot [gait]
- adjustment to uneven ground
- fixing foot or increasing pressure in different regions of foot to maintain balance
sole [plantar aspect] of foot
- covered with thick layer of skin and fatty superficial fascia
- plantar aponeurosis [deep fascia]
- muscles, nerves and vessels lie deep to the plantar aponeurosis
- muscles of the sole supplied by:
- medial and lateral plantar nerves (branches of tibial nerve)
- medial and lateral plantar arteries
sole [plantar aspect] of foot; intrinsic muscles function + innervation
10 intrinsic muscles located in the sole if the foot
function: control individual movement of the digits, stabilise the arches of the foot
all are innervated by branches of the tibial nerve:
- medial plantar nerve
- lateral plantar nerve
The muscles of the plantar aspect are described in 4 layers (superficial to deep)
plantar muscles layer 1 (3)
most superficial to the sole
located immediately underneath plantar fascia
1. abductor hallucis
2. flexor digitorum brevis
3. abductor digiti minimi
abductor hallucis; origin
medial tubercle of tuberosity of calcaneus, flexor retinaculum, plantar aponeurosis
abductor hallucis; insertion
medial side of bade of proximal phalanx of great toe
abductor hallucis; innervation
medial plantar nerve
abductor hallucis; action
abducts and flexes great toes [ hallux ]
flexor digitorum brevis; origin
medial tubercle of tuberosity of calcaneus, plantar aponeurosis, intermuscular septs
flexor digitorum brevis; insertion
both sides of middle phalanges of digits 2-5
flexor digitorum brevis; innervation
medial plantar nerve
flexor digitorum brevis; actions
flexes lateral 4 digits
abductor digiti minimi; origin
medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, intermuscular septa
abductor digiti minimi; insertion
lateral side of base of proximal phalanx of digit 5
abductor digiti minimi; innervation
lateral plantar nerve
abductor digiti minimi; action
abducts and flexes little toe
plantar muscles: layer 2
2 muscles
tendons of the extrinsic muscle flexor digitorum longus also pass through this layer
1. quadratus plantae
2. lumbricals
quadratus plantae; origin
medial surface and lateral margin of plantar surface if calcaneus
quadratus plantae; insertion
posterolateral margin of tendon of flexor digitorum longus
quadratus plantae; innervation + action
innervation: lateral plantar nerve
actions: assists flexor digitorum longus (FDL) in flexing toes 2-5
lumbricals (x4); origin
tendons of flexor digitorum longus
lumbricals; insertion
medial aspect of expansion over digits 2-5
lumbricals; innervation + action
innervation: medial 1(1st): medial plantar nerve, Lateral 3 (2nd -4th): lateral plantar nerve
actions: flex proximal phalanges, extend middle and distal phalanges of digits 2-5
plantar muscles: layer 3 (3)
3 muscles
associated with movements of the great toe [hallux] and little toe
1. flexor hallucis brevis
2. adductor hallucis
3. flexor digiti minimi
flexor hallucis brevis; origin
plantar surface of cuboid and lateral cuneiform
flexor hallucis brevis; insertion
both sides of base of proximal phalanx of great toe
flexor hallucis brevis; innervation + action
innervation: medial plantar surface
action: flexes proximal phalanx of great toe
tendon contains 2 sesamoid bones
adductor hallucis; origin
- oblique head: bases of metatarsals 2-4
- transverse head: plantar ligament of metatarsophalangeal (MTP) joints
adductor hallucis; insertion
lateral side of base of proximal phalanx of big toe
adductor hallucis; innervation + action
innervation: deep branch of lateral plantar nerve
action: adducts great toe, assists in transverse arch of foot by pulling metatarsals medially
flexor digiti minimi; origin
base of metatarsal 5
flexor digiti minimi; insertion
base of proximal phalanx 5
flexor digiti minimi; innervation + action
innervation: superficial branch of lateral plantar nerve
action: flexes proximal phalanx of little toe, assisting with flexion
plantar muscles: layer 4
2 muscle groups
associated with abduction and adduction movements of the toe
1. plantar interossei (x3)
2. dorsal interossei (x4)
plantar interossei; origin
plantar aspect of medial sides of metatarsals 3-5
plantar interossei; insertion
medial sides of bases of proximal phalanges 3-5
plantar interossei; innervation + action
innervation: lateral plantar nerve
action: adducts toes 3-5, and flex metatarsophalangeal joints
PAD: Planter interossei ADuct
dorsal interossei; origins
adjacent sides of metatarsals 1-5
dorsal interossei; insertion
1st: medial side of proximal phalanx of 2nd digit
2nd-4th: lateral sides of digits 2-4
dorsal interossei; innervation + action
innervation: lateral plantar nerve
action: abduction of toes 2-4 and flex metatarsophalangeal joints
DAB: Dorsal interossei ABduct
dorsum of foot; 2 muscles
-many of the extrinsic muscles attach to the dorsum of the foot
- 2 connected muscles:
- extensor digitorum brevis (EDB)
- extensor hallucis brevis (EHB)
- mainly responsible for assisting the extrinsic extensor muscles
- innervated by the deep fibular (peroneal) nerve
extensor digitorum brevis (EDB); origin
calcaneus [floor of tarsal sinus]: interosseus talocalcaneal ligament, stem of inferior extensor retinaculum
extensor digitorum brevis (EDB); insertion
tendons of extensor digitorum 2-4
extensor digitorum brevis (EDB); innervation
deep fibular [peroneal] nerve
extensor digitorum brevis (EDB); actions
aids extensor digitorum longus [EDL] in extending toes 2-4 at metatarsophalangeal and interphalangeal joints
extensor hallucis brevis (EHB); origin
common with the extensor digitorum brevis
extensor hallucis brevis (EHB); insertion
dorsal aspect of base of proximal phalanx of great toe
extensor hallucis brevis (EHB); innervation
deep fibular nerve [peroneal]
extensor hallucis brevis (EHB); actions
aids extensor hallucis longus [EHL] in extending great toe at the metarsophalangeal joint
nerves of the foot
cutaneous
arteries of the foot
terminal branches of anterior and posterior tibial arteries
- dorsal pedis
- plantar arteries: medial and lateral
dorsalis pedis artery
- dorsal artery of foot
- continuation of anterior tibial artery
- continuations:
- deep plantar artery [deep plantar arch]
- lateral tarsal artery
- 1st dorsal metatarsal artery
- arcuate artery
- 2nd, 3rd, 4th dorsal metatarsal arteries
- dorsal digital arteries
arteries of sole of foot
- posterior tibial artery continues as medial and lateral plantar arteries
- medial plantar artery - smaller terminal branch
- lateral plantar artery
- larger terminal branch
- deep plantar arch
- joins deep plantar artery [branch of dorsalis pedis]
- plantar metatarsal arteries
- plantar digital arteries
venous drainage of foot
- superficial and deep veins
- deep venous drainage: paired veins accompanying arteries
- superficial veins are subcutaneous and unaccompanied by arteries
- dorsal venous arch
