E2- Hip and knee Flashcards
what can the shape of the femur be impacted by
growth of the ossification center
force of m activation
WB
circulation
trauma
what is coxa vara
less than 125-105 deg
hip bend inward
cause genu valga
what is coxa valga
greater than 125-140 deg
hip bend outward
cause genu vara
what is femoral torsion
relative RT between the shaft and neck
what is normal anteversion of femoral torsion
15 deg (8-20)
what is excessive anteversion
greater than 15-35
what is retroversion
less than 15 deg
what can excessive anteversion cause
hip dislocation
OA
increase contact stress
in toeing
how does increased anteversion affect motion
less ER more IR
how does retroversion affect motion
increase ER less IR
what is the normal for creg’s test
8-15 deg
where is the femoral head located
inferior to mid 1/3 of inguinal lig
posterior to center is fovea
what is the lig teres
tubular, synovial lined connective tissue
contains mechanoreceptors
what is housed in the lig teres
acetabular artery
what is the acetabulum
deep, cuplike socket
what is the acetabular notch
60-70 deg opening
what is in the acetabular fossa
fat, blood vessels, synovial membrane, ligaments
where is the normal contact of the femoral head
along the lunate surface
what is the lunate surface
covered in articular cartilage, sup-ant, where the femoral head contacts
when is the joint force highest for the lunate surface
walking
what happens to the acetabulum during midstance of the gait cycle
300% BW
notch widens
lunate deforms
increase contact area/decrease pressure
what is the acetabular labrum
strong, flexible ring of fibrocartilage rim of acetabulum
where is the transverse acetabular lig
spans the acetabular notch
where is the labro-chondral junction
internal labrum blends with the articular cartilage of acetabulum
where is the 13% of forces in the acetabulum coming from during the swing phase
muscles
passive structures
what is the function of the acetabulum labrum
mechanical stability “grip”
deepens socket
keeps negative pressure, fluid sealed
what is the acetabular alignment
projects laterally, inf/ant inclination
what is dysplastic acetabulum
malformed, does not fully cover the femoral head
what can dysplastic acetabulum cause
chronic dislocation
OA
pain
what is the center edge angle
degree acetabulum covers femoral head
what is acetabular anteversion angle
extent to which the acetabulum faces anteriorly
what is the difference between acetabulum anteversion and femoral version (ante/retro)
femoral- axis of femur and transcondylar axis of knee
acetabulum- acetabular morphology
what ligaments reinforce the external capsule of the hip
iliofemoral
pubofemoral
ischiofemoral
what elongates the iliofemoral lig
hip EXT and full ER
what elongates the pubofemoral lig
hip ABD/EXT and some ER
what elongates the ischiofemoral lig
taught in IR and hip ABD
what is the iliocapsularis
deep hip flexor
lateral to iliacus
deep to rectus femoris and sartorius
how could a person with parapelgia stand upright
by leaning on the iliofemoral lig to make them taut and hold their body weight
what is the closed pack position of the hip
full EXT
slight IR and hip ABD
what is the position of max joint congruity of the hip
90 flexion
moderate ABD and ER
true/false
max jt congruity of the hip is equivalent to the closed pack position of the hip
false
closed pack position is not associated with the position of max congruity
what is the osteokinematics of the femoral on pelvic
femur moves on fixed pelvis
what is the osteokinematics of the pelvic on femoral
RT of pelvis on fixed femurs
what is the deg of motion of femoral on pelvic hip flexion
120-140
results in posterior tilt and lumbar flexion
how does the deg of motion change for hip flexion with LE extended
70-80 deg
due to hamstring tension
what is the deg of motion of femoral on pelvic hip extension
18-30 deg
what is the deg of motion of femoral on pelvic hip ABD
40-55 deg
what can limit motion of hip ABD
pubofemoral lig
adductor muscles
what is the deg of motion of femoral on pelvic hip ADD
20-25 deg
what can limit motion of hip ADD
ABD muscles
piriformis
ITB
what is the deg of motion of femoral on pelvic hip RT
IR- 30-45
ER- 32-50
what is ipsidirectional lumbopelvic rhythm
lumbar and spine move in same direction
what is maximized in ipsidirectional lumbopelvic rhythm
angular displacement of trunk
what is contradirectional lumbopelvic rhythm
lumbar and pelvis move in opposite direction
above lumbar stays stationary
used in walking
when is the pelvis in contradirectional lumbopelvic rhythm
walking
sitting with ant/post tilts
what is the contradirectional rhythm of hip flexion in sitting
ant pelvic tilt
lumbar spine ext
sacrum nutates (flexes)
what is the contradirectional rhythm of hip extension in sitting
post pelvic tilt
lumbar spine flx
sacrum counternutate (extends)
what is the contradirectional rhythm of R hip ABD of support leg with walking
L iliac crest hip hikes
L lateral flexion
what is the contradirectional rhythm of R hip ADD of support leg with walking
L iliac crest drops
R lateral flexion
how does the hip roll/slide with open chain arthrokinematocs
convex femur rolls/slides in opposite directions
what is the arthrokinematics of open chain exercise of hip flx
roll ant
slide post/inf
what is the arthrokinematics of open chain exercise of hip ext
roll post
slide ant/sup
what is the arthrokinematics of open chain exercise of hip IR
roll ant
slide post
what is the arthrokinematics of open chain exercise of hip ER
roll post
slide ant
what is the arthrokinematics of open chain exercise of hip ABD
roll sup
slide inf
what is the arthrokinematics of open chain exercise of hip ADD
roll inf
slide sup
what is the path of the arthokinematics while the hip is doing IR/ER
transverse
what is the path of the arthokinematics while the hip is doing ABD/ADD
longitudinal
what m are the primary hip flexors
iliopsoas
sartorius
rectus femoris
adductor longus
pectineus
when is the iliopsoas best recruited
prominent femoral-hip flexor
trunk/pelvis flexor over fixed thighs
swing phase of walk
frontal plane stability
when is the psoas minor best recruited
stabilize the underlying position of psoas major
what are the primary action of sartorius
hip flex, abd, er
what is the TFL innervation
superior gluteal n L4-S1
what is the ITB innervation
superior gluteal n L4-S1
inferior gluteal n L5-S2
what innervates the sartorius
femoral n L2-4
what m do the obturator n innervate
hip adductors
obturator externus
what m has isometric torque at hip
rectus femoris
what innervates the rectus femoris
femoral L2-4
what are the primary hip add
pectineus
adductor longus
gracilis
adductor brevis
adductor magnus
what m are in the superficial layers of hip adductors
pectineus
adductor longus
gracilis
what m has the longest moment arm to promote hip flx
rectus femoris
what m are in the middle layer of hip adductors
adductor brevis
what m are in the deep layer of hip adductors
adductor magnus
what m can be an extensor and flexor when close to full extension or flexion
adductor magnus
when does IR m increase in torque
60-90 deg of hip flexion
piriformis becomes IR at 60 deg
what is the function of the IR during gait
during stance they rotate the pelvis on the femur
what are the primary m of hip extensors
glute max
hamstrings
post head of adductor magnus
when do adductors recruit to become extensors
greater than 70 deg flexion
what is the innervation of glute max
inferior gluteal n L5-S2
what is the innervation of the hamstrings
sciatic L5-S2
what is the innervation of the post head of adductor magnus
obturator L2-4
what are the main 4 hip flexors
tensor fascia latte
rectus femoris
sartorius
iliopsoas
if a patient is in a significant lean, what m has an increase of their moment arm
hamstrings
increase passive tension
what is the m mechanics of femoral on pelvic hip extension with going up a hill
large extension torque
rectus femoris and glute max cooperation
rectus= flexion torque ant pelvic tilt, HS/gastoc/glutes/adductor= ext torque
what are the primary hip abductors
glute max and medius
TFL
what m has the largest percentage of hip abductors
glute medius
what are the primary hip ER
glute maximus
quadratus femoris
gemellus sup and inf
obturator internus
piriformis
what decelerates the drop of the hip when the other leg is kicking a soccer ball
glute medius
what happens with pelvic on femoral RT during ER with R LE planted
R LE planted and ER contraction allows the body to rotate to the L
what m is at work with planting and cutting in sports
glute max can ER and EXT for turn and push off
what is m are decelerating the planting and cutting action in sports
adductors and IR
what are symptoms of greater trochanter syndrome
lateral hip pain
common >40 yr F
achy, tender near GT
what deviations are present with GTPS
weak hip ABD and gait deviations
when is GTPS most painful
standing on one leg
climbing hills
prolong walking
what is GTPS
tendinopathy of glute med/min and or bursas
why is GTPS most panful in midstance
tension stress and compression
what biomechanical problems can develop with hip abd weakness
postural instability
falls
patella-femoral pain
LBP
ankle pain
knee instability
what are symptoms of OA in the hip
pain in groin, buttock, thigh, knee
crunching
what is OA of the hip
narrowing of the joint space, deterioration of cartilage, thickened capsule leads to inability to move the hip to perform routine activities
what is hip resurfacing
trim the natural bone and apply metal coverings to head and acetabulum
what can be the biomechanical consequence of a positive coxa vara
increase moment arm of ABD
more joint stability
what can be the biomechanical consequence of a negative coxa vara
increase shear of femoral neck
decrease moment arm of ABD
what can be the biomechanical consequence of a positive coxa valga
decrease shear force on femoral neck
increase moment arm of ABD
what can be the biomechanical consequence of a negative coxa vara
decrease moment arm of ABD
joint displacement
what can cause a acetabular labrum tear
RT, repetitive and near end range motions
hip dislocation, deep squat, strenuous activities
what can be secondary pain with an acetabulum labrum tear
obturator internus and pelvic floor pain
what is dysplasia of the hip
poorly formed acetabulum during development due to intrauterine position or abnormal neuromuscular development
what are complications of hip fx
reduced independence
shorten life
immobility
blood clots
bed sore
UTI
why is usage of a cane important
reduces compressive forces if in opposite
reduces JRF by reducing activation of hip ABD
what is the normal alignment of the knee angle
170-175 is normal genu valga
what is excessive genu valga
<170 creates knock knee
what is genu vara
> 180 creates bow leg
what reinforces the anterior connective tissues in the knee
med/lat retinacular fibers extensions of ITB and vastus lat/med that connect to femur/tibia/patella/quads/ligs/mensci
what are the anterior knee muscular reinforcements
quads
what reinforces the lateral connective tissues in the knee
LCL
lat patellar retinacular fibers
ITB
what are the lateral knee muscular reinforcements
biceps femoris
popliteus tendon
lat head of gastroc
what reinforces the posterior connective tissues in the knee
oblique popliteal lig
arculate popliteal lig
what are the posterior knee muscular reinforcements
popliteus
gastroc
hamstrings
what reinforces the posterior-lateral connective tissues in the knee
arcuate popliteal lig
LCL
popliteofibular lig
what are the posterior-lateral knee muscular reinforcements
tendon of popliteus
what is the fabella
sesamoid bone in the posterolateral capsule of the knee joint
what attaches to the fabella
fabellofibular lig
oblique popliteal lig
fabella to fibular head
what reinforces the medial connective tissues in the knee
anterior- medial patella retinacular fibers
medial- medial patella retinacular fibers, MCL
posterior- SM tendon, posterior capsule, posterior oblique lig, pes anserine
what are the medial knee muscular reinforcements
semimembranuous
SGT
pes anserine
what are extensions of synovial membrane in the knee
14 bursae
what are the fat pads of the knee
suprapatellar
deep infrapatellar
what provides stability for the tibiofemoral jt
soft tissue
what does the menisci do for the tibiofemoral jt
form seat for the femoral condyles
where is the menisci anchored on the tibia
intercondylar region at ant/post horns
what attaches to the external edge of meniscus attached to the tibia and what does it allow
coronary lig and pivoting
what are the coronary ligs connected by
transverse lig anteriorly
what m attach to the menisci
quads
semimebranosuous
popliteus
what is the function of the m that attach to the menisci
stabilization
what are the primary function of tibiofemoral jt
decrease compressive forces
what is the secondary function of tibiofemoral jt
stabilize jt motion
lubricate articular cartilage
proprioception
arthokinematics
what are common mechanisms of injury at tibiofemoral jt
axial RT with flexed knee - menisci
bucket handle
medial injury due to valgus force - MCL/post med capsule
what can increase the risk of menisci tear
lig laxity (ACL)
malalignment
which m has the most direct attachment to the mensci
popliteus
what is the red zone of the menisci
peripheral 1/3 of menisci
good for healing
what is the white zone of the menisci
inner 2/3 of menisci
nutrition from synovial fluid
when does RT occur in the knee
slight flexion
what is the range of flexion at the knee
130-150
what is the range of extension at the knee
5-10 deg hyperextenion
how is RT named for the tibiofemoral jt
position of tibial tuberosity relative to anterior femur
at 90 deg of hip flx, what is the deg of axial RT of tibiofemoral jt
40-45 deg
2:1 ER exceeds IR
what is the arthro of tibial on femoral ext
tibia rolls and slides anterior meniscus ant by quads
what is the arhro of femoral on tibia ext
femoral condyles roll ant and slide post
quads direct rolls and stabilize menisci
what “screw home” motion is required during full ext to increase jt congruence and stability
10 ER during last 30 deg ext
OC- tibia ER
CC- femur IR
what drives the “screw home” concept for EXT
shape of the condyles
passive ACL tension
slight lateral pull of quads
what m unlocks the knee for “screw home” for FLX
popliteus
what m help stabilize axial RT in flexion at the knee
popliteus and semimembranosus
What does the MCL blend into
medial meniscus
what does the LCL blend into
bicep femoris tendon
what is the primary function of MCL and LCL
limit motion in frontal plane
when knee is extended what lig fights valgus forces
MCL
when knee is extended what lig fights varus forces
LCL
what are secondary functions of the LCL and MCL
general stabilizing tension
extreme RT
what resist valgus forces
MCL
ACL
PCL
lateral meniscus comp
pes anserine
med gastroc
what resist varus forces
LCL
posterior-lateral capsule
ITB
bicep femoris tendon
jt contact medial
ACL/PCL
lat gastroc
what does MCL resist
valgus
knee ext
extreme ER at knee
what does LCL resist
varus
knee ext
axial RT
what does the posterior capsule of the knee resist
knee ext
OPL- resist ER
varus
what does the ACL resist
resist ext - ant tibia or post femur
extreme varus, valgus, RT
what does PCL resist
knee flexion- post tibia or ant femur
extreme varus, valgus, RT
when is the ACL taut
some fibers in FLX
increase taut in EXT
where does ACL attach in tibia
anterior runs posterior
what happens to the tibia when the quad causes ext?
what becomes taut
tibia is pulled anterior
ACL limits the slide
how do you perform anterior drawer test
90 deg knee flex
pull prox tibia ant
ACL prevents slide
hamstrings can activiate and limit slide
what factors play into ACL tear
speed and direction
compressive and shear force
control and timing of m forces
integrity and strength of tissue
alignment
how can strong quad activation cause ACL tear
valgus collapse
excessive ER, femur IR
what is the posterior drawer test
knee 90 deg flx
prox end tibia post
limits femur ant
what is the stabilizer of the patellafemoral jt
quad
what moves when the it is tibia on femoral
tibia and patella on femoral condyles
what moves on femoral on tibial
femur and femur condyles on patella
true/false
the more flexion of the knee (60-90 deg) the more contact of the patella on the femoral condyles
true
when is there the least amount of contact of the patella and femoral condyles
20 deg flexion and 135 deg flex
what m does knee ext
quadriceps- femoral n
what m does knee internal rotation
sartorius- femoral n
gracilis- obturator n
SM- sciatic (tibial) n
ST- sciatic (tibial) n
popliteus - tibial n
what m does knee external rotation
bicep femoris- sciatic (tibial and fibular) n
what m does knee flexion
SM - sciatic
ST- sciatic
bicep femoris- sciatic
sartorius/gracilis - femoral/obturator
gastroc/plantaris- tibial
popliteus- tibial
what innervates the posterior capsule of knee
posterior tibial n
what innervates the medial knee and post/post med capsule
obturator n
what innervates the ant-medial and ant-lateral capsule
femoral n
what group in the quads has the most extension torque
vastus group
what vastus m has fibers in 2 directions
vastus medialis
VML and VMO
what m has the greatest cross section in the quads
vastus lateralis
what does the articularis genu do
pull the capsule proximal
what is the knee extensor mechanism
forms the quadriceps tendon
what is the quad to hamstring ratio
knee ext torque is 2/3 of knee flx
how does the quads do eccentric functions
rate of descent
dampens impact/load on knee - walking
what are the concentric functions of the quads
accelerates tibia/femur toward ext
jump, step up, running
where is the longest moment arm during a long arc quad
a. 90 flx
b. 45 flx
c. 0 ext
0 ext due to the the most amount of weight to hold the leg straight
less patella contact on the femur
where do you generate more force in a squat position
a. 90 flx
b. 45 flx
c. 0 ext
90 deg flx due to the amount of weight the patient has to force upward
why does extensor lag happen
external torque is too great for internal torque (quads) to happen
what impacts the length of the knee extension moment arm
shape/position of patella
shape of distal femur
evolute
what factors associate with joint compression forces of the PF jt
quads force
knee flexion angle
what is the functional role of the patella
acts as a spacer and increases the internal moment arm (pulley)
