lower leg (incl knee) Flashcards
what type of joint is knee joint
hinge synovial
mainly allows for flexion and extension (+ small degree of medial and lateral rotation)
articulations of knee joint
tibiofemoral: medial and lateral condyles of femur articulate with tibial condyles. Weight-bearing component of knee joint
patellofemoral: anterior aspect distal femur atriculates with patella. It allows tendon of quadriceps femoris to be inserted direcly over knee
blood and nerve supply to knee joint
blood: genicular anastomoses around knee which are supplied by genicular branches of femoral + popliteal arteries
nerve supply by the nerves that supply the muscles crossing the joint: femoral, tibial, common fibular nerves
collateral ligements of knee
2 strap like ligaments that stabilise hing motion of knee, preventing excessive medial or lateral movement
fibular (lateral) collateral ligament
tibial (medial) collateral ligament
cruciate ligaments of knee
2 ligaments that cross obliquely to form x shape
anterior cruciate: prevents anterior dislocation of tibia onto femur
posterior cruciate: prevents posterior dislocation of tibia onto femur
popliteus muscle
small muscle that helps release fully extended (locked) knee
when flexing from fully extension the muscle rotates laterally on tibia (or vice-versa) allowing for unimpeded movement of joint
what are the menisci of knee joint
crescent shaped plates of fibrocartilage direcrtly on the articular surface of the tibia
functions of menisci of knee joint
deepen articular surface of tibia, thus increasing joint stability
act as shock absorbers by increasing surface area to further dissipate forces
damage to what ligament usually results in a medial meniscal tear
tibial collateral ligament
bursae of knee joint
suprapatellar bursa (communicates with articular cavity of joint)
prepatella bursa
infrapatella bursa
semimebranosus bursa
what muscle causes knee joint extension
quadriceps femoris
what muscle causes knee joint flexion
hamstrings
sartorius
popliteus
what muscle causes knee joint lateral rotation
biceps femoris
what muscle causes knee joint medial rotation
semimembranosus semiteninosus gracilis sartorius popliteus
when can lateral and medial rotation of knee joint occyr
only when knee is flexed
what holds tibia and fibula together
interosseous membrane (sheet of fibrous material)
proximal tibio-fibula joint
joint type
articulation
arteries
nerves
plane type synovial joint
articulation between head of fibula and lateral condyle of tibia
inferior genicular arteries and anterior tibial recurrent arteries
branches of common fibular nerve and nerve to popliteus
distal tibio-fibular joint
joint type
articulatin
arterial supply
nerve supple
fibrous joint
articulation between fibular notch of distal tibia and fibula
branches fibular artery and anterior + posterior tibial arteries
deep peroneal and tibial nerves
tibial tuberosity
anterior bony prominence felt ~3-4cm below knee joint
patella tendon attaches to this
what bone makes up medial malleolus
tibia
what bone makes up lateral malleolus
fibula
plantarflexion of ankle joint
movement of ankle downwards (pointing toes)
dorsiflexion of ankle joint
movement of ankle upwards
eversion of ankle joint
movement of ankle outwards
inversion of ankle joint
movement of ankle inwards
innervation and blood supple of muscles of anterior compartment leg
deep fibular nerve
anterior tibial artery
what are the muscles of anterior compartment leg
tibialis anterior
extensor digitorum longus
extensor hallucis longus
fibularis tertius
function of tibialis anterior
dorsiflexion and inversion foot
function of extensor digitorum longus
extension lateral 4 toes and dorsiflexion foor
function of extensor hallucis longus
extension great toe and dorsiflexion of foot
funciton of fibularis tertius
eversion and dorsiflexion foot
what are the 2 divisions of the popliteal artery as it enters leg
anterior tibial artery
tibioperoneal trunk (which bifurcates into posterior tibial and fibular arteries)
muscles of lateral compartment leg and nerve supply and function
both superficial fibular nerve
fibularis longus: eversion and plantarflexion foot (also supports lateral + transverse arches foor)
fibularis brevis: eversion foot
anterior aspect of foot
dorsum of foot
ankle joint
tibia and fibula and the talus bone
functionally a hinge type synovial joint - permitting dorsiflexion and plantarflexion foot
how it the ankle a mortise joint
bones at the superior aspect of joint (tibia and fibula) provide a socket into which the talus fits into
medial ligament of ankle joint
deltoid ligament
medial malleoulus
4 ligaments which fan out attaching to talus, calcaneus and navicular bones
resist over-eversion of foot
lateral ligament of ankle joint
originate lateral malleolus,
resist over-inversion
anterior talofibular
posterior talofibular
calceneofibular
what ligament is most likely to be damaged in ankle sprain
lateral ligement
- it is weaker than medial ligament
- it resists inversion
(anterior talofibular ligament is most at tisk of irrevesrible damage)
neurovascular supply to ankle joint
arterial supply derived from malleolar branches of anterior tibial, posterior tibial and fibular arteris
innvervation by tibial, superficial fibular and deep fibular nerves
what muscles produce ankle plantarflexion
muscles in posterior compartment leg
- gastrocnemius
- soleus
- plantaris
- posterior tibialis
what muscles produce ankle dorsiflexion
anterior leg muscles
- tibialis anterior
- extensor hallucis longus
- extensor digitorum longus
what is the popliteal fossa
fat filled diamond shaped space located posterior to knee joint
main path by which vessels and nerves pass between thigh and leg
superomedial border of popliteal fossa
semimembranosus muscle
superolateral border of popliteal fossa
biceps femoris muscle
infromedial border popliteal fossa
medial head of gastrocnemius muscle
inferolateral border popliteal fossa
lateral head gastrocnemius
plantaris muscle
floor of popliteal foss
posterior surface knee joint capsule
popliteus muscle
posterior femur
rood of popliteal fossa
2 layers: popliteal fascia and skin
contents of popliteal fossa
from medial to lateral
- popliteal artery
- popliteal vein
- tibial nerve
- common fibular nerve
also contians fat and popliteal lymph nodes + vessels
when does femoral artery become popliteal artery
as it emerges from adductor hiatus
what nerve innervates all muscles of posterior leg
tibial nerve, a terminal branch of sciatic nerve
superficial posterior muscles of leg and functions
gastrocnemius muscle: plantarflexion ankle and flex knee
plantaris muscle: plantarflexion ankle and flex knee
soleus muscle: plantarflexion ankle
where do all superficial posterior leg muscles insert
into calcaneus of foot (heel bone) via the calcaneal tendon (aka achilles tendon)
2 bursae associated with calcaneal tendon
subcutaneous calcaneal bursa
deep bursa of calcaneal tendon
deep muscles of posterior leg
popliteus: laterally rotates femur on tibia unlocking knee so can flex
tibialis posterior: invert and plantarflex foot + maintains medial arch
flexor digitorum longus: flexes lateral 4 toes
flexor hallucis longus: flex great toe
the subtalar joint
articulation between 2 of the tarsal bones in foot: talus and calcaneus
plane synovial joint
articulating surfaces of subtalar joint and movement
inferior surface talus with superior surface calcaenus
inversion and eversion
talocalcaneonavicular joint
ball and socket joint which allows foot to pivot from side to side
function of plantar fascia foot
supports arches of foot
acts as spring when pushing off in normal walking gait
proximal row of tarsal bones
talus
calcaneus
intermediate row of tarsal bones
navicular bone
distal row of tarsal bones
cuboid 3 cuneiforms (lateral, intermediate + medial)
arches of foot
two longitudinal (medial and lateral) one anterior transverse
distribute weight and act as shock absorber
what are the arches of foot formed by
tarsal and metatarsal bones and supported by ligaments in foot
passive factors that maintain integrity of foot arches
plantar aponeurosis
short plantar ligament
long plantar ligament
plantar calcaneonavicular ligament
dynamic factors that maintain integrity of foot arches
intrinsic plantar muscles fibularis longus tibialis anterior tibialis posterior flexor hallucis longus
extrinsic vs intrinsic muscles of foot
extrinsic: arise from compartments of leg.
intrinsic: within foor and responsible for fine motor actions
intrinsic muscles of dorsal aspect foot
extensor digitorum brevis: extend medial 4 toes at MTP and interphalangeal jonts
extensor hallicus brevis: extend great toe at MTP
deep fibular nerve
1st most superficial layer of plantar aspect foot muscles
abductor hallucis
flexor digitorum brevis
abductor digiti minimi
what does abductor hallucis do
abducts and flexes great toe
what does flexor digitorum brevis do
flex lateral 4 digits at proximal interphalangeal joints
what does abductor digiti minimi do
abducts and flexes 5th digit
second layer of planter aspect foot muscles
quadratus plantae - flex lateral 3 digits
lumbricals
-4
flex at MTP joint
extend at interphalangeal joint
third layer of planter aspect foot muscles
deep intrinsic muscles
adductors and short flexors of toes
fourth layer of planter aspect foot muscles
interossei
nerve supply abductor hallucis
median plantar nerve
nerve supply flexor digitorum brevis
median plantar nerve
nerve supply abductor digiti minimi
lateral plantar nerve
quadratus plantae nerve supply and action
flex lateral 4 toes
lateral plantar nerve
lumbricals action and nerve supply
flex proximal phalanges and extend digital phalanges lateral 4 toes
medial one: medial plantar nerve
lateral 3: lateral plantar nerve
