Knee, Foot, and Ankle Flashcards
The largest jt in body is the
knee jt
bones of knee
distal femur, proximal tibia, and patella
What bone of knee is major weight-bearing bone of leg?
tibia
purp of patella
Patella protects the ant knee and creates an improved angle of pull for the quads that results in a mech adv during knee ext
what are the 2 major ligaments in knee?c
cruciate and collateral
what ligaments of knee cross w/in the jt cavity between the femur and tibia and are vital in maintianing ant-post and rotational stability of knee
crucuiate ligaments
What ligaments connect the femur w/ leg bones, and aid in stability and counteract valgus and varus forces
collateral ligaments
MCL attaches where, but LCL doesnt
MCL to medial mensicus, but LCL doesnt attach to lateral mensicus
the knee has what 2 jts?
tibiofemoral and patellofemoral jts
Although a vital attachment site for knee structures, THIS JT is not considered compartment part of knee?
prox tibiofibular jt
What jt of knee is the primary jt of knee and is primarily a hinge jt allows flexion and extension of knee?
tibiofemoral jt
tibiofemoral jt is also considered a
bycondylar jt cuz of its rotational components about the vertical axis
tibiofemoral jt is formed by what?
TF jt formed by the articulation of the medial and lateral femoral condyles w/ medial and lateral tibial plateaus
Menisci improve what
congrugency of jt surfaces allowing better distrubtion of jt pressurem add stability, aid in shock absportion, provide jt lubrication, aid in loading bearing, add ant-post stab, and protect articular cartilage
medial menisici vs lateral mensici
medial mensici are larger, thinner, and more “C” shaped than the lateral mensici
What typically extends more distally than the lateral condyle gives kneee a slight valgus arranegment
medial femoral condyle
What jt is an arthrodial jt formed by the post asoect of patella and PF groove betweeen condyles of femur
patellofemoral jt
How is Q angle formed
Q angle is formed from the line connecting ASIS to center of patella and the line connecting the center of the patella to the tibial tuberosity
Q angle determines what?
line of pull of patella at the PF jt
Normal Q angle for females is
18
normal Q angle for males is
13
A Q angle below normal is
genu varum, varus, aka bow legged
Q angle greater than normal is
genu valgum, valgus, aka knock-kneed
Tibiofem jt movement
flexion, ext in sag plane
full extension of knee is how many degrees
0
full flexion of knee is how many degrees
140 deg
When knee is bent/flex the Tibfemoral jt is capable of what?
internal and ext rot
What is the screwing home mechanism?
During final few degrees of ext knee, the tibia externally rotate on femur bringing knee into closed pack or locked position
quadriceps muscle action at knee
extend knee (Q = Hf + Ke)
Anterior muscles of knee
quads
quads insertion
superior aspect of patella and ultimately to the tibial tuberosity by patellar ligament
RF origin
AIIS
RF muscle action
RF = Hf, Ke
3 vasti origin
proximal femur
vastus lateralis and medialis are what kind muscles with what kind of pull
pennate muscles that pull on patella at oblique angles
Posterior muscles of knee
hamstrings, sartorius, gracilis, popliteus, gastroc
biceps femoris long head O
ischial tuberosity
biceps femoris short head O
mid-femur
bicep femoris insertion
lateral condyle of tibia and head of the fibula
biceps femoris muscle action
flex and ext rot knee
extend and ext rot hip
SM and ST muscle action
flex and int rot knee
extend and int rot hip
sartorius origin
ASIS
The tendons of sartorius, gracilis, and SM join to form the
pes anserinus
Pes anserinus insertion
anteromedial aspect of prox tibia, just inferior to tibial tuberosity
gastroc muscle action
flex knee; plantarflex foot
popliteus is weak
knee flexor
purpose of popliteus
unlocks the extended knee by laterally rotating the femur on the fixed tibia
describe the ankle jt
synovial hinge jt betwen distal tibia and fibula dome of talus
what is the malleolar mortise
a tight fibrous syndesmosis between tibia nad fibula unites the distal ends of bones to form mm into which te trochlea “dome: of talus fits
a plane syn jt between talus and calcaneus is what jt
subtalar jt
talocrural jt allows
15-20 dorsi, 50 deg plantarflex in sagg plane
subtalar allows
20-30 degrees inversion, 5-15 eversion
what jts of ankle permit gliding motion?
midtarsal and tarsometatarsal
foot flexion and ext of digits jts
metatarsophalangeal and interphalangeal jts
pronation of foot is combo of
talocrural dorsiflexion, subtalar eversion, and forefoot abd
supination of foot is combo of
talocrural plantarflexion, subtar inversion, and forefoot adduction
Ant muscles for foot
tibialis ant, peroneus tertius, extensor digitiorum longus, extensor hallucis longus
tibialis ant, peroneus tertius, extensor digitiorum longus, extensor hallucis longus muscle action
ankle dorsiflexors
what muscle inverts foot?
tib ant
what muscle everts foot?
peroneus tertius
Extensor hallucis longus acts to do what?
extend big toe and extensor digitorum longus extend digits 2-5
lateral muscles of ankle and foot
peroneus longus, brevis
peroneus longus, brevis muscle action
evert foot and assist w/ plantarflexion
Superficial post muscles of foot
gastroc, soleus , plantaris
gastroc, soleus , plantaris muscle action
plantarflexors
gastroc has more what than soleus
gastroc has more fast twitch fibers than soleus
When is gastroc used over soleus?
Gastroc is used more during dynamic, higher force activiies
soleus is more active in
postural and static contractions
At 90 degress knee flexion, the gastroc expierneces what?
passive insufficiency and thus is less active when knee is straight aka 0 deg flexion
during calf raise exs, keep knee how to emphasize gastroc and soleus repstiviely
gastroc=striaght leg
soleus = bent leg
deep post muscles of foot and ankle
flexor digitorum longus, felxoro hallucis longus, tiab post, popliteus
flexor digitorum longus, felxoro hallucis longus, tiab post muscle action
plantar flexors and inverters
