Hip Joint Complex Flashcards
congruence
the body surface area contact between the 2 adjoining bones at a synovial joint
high congruence = ?
lots of surface area contact
congruence usually relates to ____
stability
-most congruence = most stable
-NOT TRUE FOR THE HIP, but generally true for most joints
joint stability
a resistance to dislocation or going into an unhealthy ROM
joint laxity
how much a joint can move around
-how much play it has
close packed
the most congruent position
loose packed
-the least congruent position
-instability at the joint
head, arms, + trunk (HAT)
lump sum mass of the upper torso, including the limbs
anthropometrics
making measurements of the body, specific to an individual
describe the sex difference for the sacroiliac (SI) joint
women have higher joint laxity
describe the ligaments across the SI joint
-and the reason why
there are very strong ligaments across the SI joint
-for stability
what is the hip joint
coxofemoral joint
-also called femoroacetabular joint
what is another name for coxofemoral joint
femoroacetabular joint
describe the coxofemoral joint
one of the largest, most congruent, + most stable joints
what is the articulation of the coxofemoral joint between
os coxa + femoral head
-the femur articulates with all 3 bones of the os coxa since they split the acetabulum
what type of joint is the coxofemoral joint
-diarthrodial/synovial joint
-ball + socket
how many df does the coxofemoral joint have
3 rotational df
-sagittal- flexion/extension
-frontal- abduction/adduction
-transverse- medial/lateral rotation
primary function of the coxofemoral joint
to support the weight of the HAT
-both in the static posture (upright) + dynamic postures (walking, running, stairclimbing, etc.)
acetabulum
socket of the hip joint
what is the acetabulum covered with
articular catilage that thickens perpetually at the rim
describe the orientation of the acetabulum
faces obliquely anteriorly, laterally, + inferiorly
-this varies by person
someone with a more anteriorly facing acetabulum has a narrower/wider squat form
narrower
describe the thickening of the acetabulum
thickened by the labrum, which contains free endings
labrum
fibrocartilage on the acetabulum rim
-contains free nerve endings to serve a pain + proprioceptive function
describe the acetabulum when unloaded
acetabulum has smaller diameter than femoral head
describe the acetabulum when loaded
acetabulum forms around the femoral head
femur
ball side of the hip joint
describe the size of the femoral head
slightly larger than a hemisphere
describe the orientation of the neck of the femur in articulation
articulates superiorly, anterioly, + medially
describe the amount of movement at the sarcoiliac joint (SI)
small movement
describe the sex difference in the SI joint
higher joint laxity for women
describe the ligaments across the SI joint
very strong ligaments for stability
what movement occurs at the SI joint
nutation/counternutation
nutation/counternutation
rotation of the sacrum in the sagittal plane
nutation
sacrum tipping forward
counternutation
sacrum tipping backward
describe SI load transmission
shear forces
shear forces
move in opposite directions
Wolff’s law
-stress adaptation of internal structure over time
-the bone will remodel in response to repetitive loading
using Wolff’s law, what bone’s (2) internal structures develop in response to loads
-pelvis
-femur
what type of bone do we see Wolff’s law occur in
spongy/trabecular bone
what is the result of normal weight bearing of the HAT
bending stresses in the shaft of the femur
when there is loading, how does the femur orient + how does this effect the femur?
femur deflects our laterally when there is loading
-causes tensil stress on the outside
-causes compressive stress on the inside
stability
-the ability to resist dislocation
-resistance to movement while staying in a healthy ROM
factors that influence stability
-shape + congruence of bones
-supporting structures (ligaments, muscles, joint capsule, cartilage)
how many capsular ligaments provide stability to the hip joint
3
name the 3 capsular ligaments of the hip joint
-ischiofemoral ligament
-iliofemoral ligament
-pubofemoral ligament
name 2 characteristics of the 3 capsular ligaments of the hip joint
-all become taut with hip extension
-continuous with joint capsule
what is the strongest ligament at the hip
iliofemoral
ischiofemoral ligament is anterior/posterior
posterior
ischiofemoral ligament gets taut during which action
hip extension
iliofemoral ligament
fan-shaped ligament that resembles an inverted y
iliofemoral ligament becomes taut during which 2 actions
-hyperextension
-hip extension
pubofemoral ligament
forms a z on the anterior capsule with the iliofemoral ligament
pubofemoral ligament becomes taut during which 2 actions
-hip extension
-hip abduction
how many intracapsular ligaments does the joint have
1
what is the intracapsular ligament of the hip
ligamentum teres
ligamentum teres
-secondary stabilizer preventing dislocation
-conduit for blood supply
-contains innervation for pain sensation
hip position: max bony congruence/contact
flexed, abducted, external rotation
-frog-legged position
dos the hip’s position of max bony congruence have the highest stability
no
hip position: most stable
extension, slight abduction, internal rotation
for the hip’s most stable position, what does extension do
further tightens the capsular ligaments
hip position: least stable
flexion + adduction
angle of Wilberg
angle between vertical line drawn from the center of the femoral head to the bony edge of its acetabulum
what does the angle of Wilberg measure
approximate measure of superior weight-bearing surface’s (lunate surface) inferior tilt of acetabulum
what is the superior weight-bearing surface of the acetabulum called
lunate surface
what is another name for the angle of Wilberg
center edge angle
more downwards tilt = larger/smaller angle of Wilberg = more/less stress = decreased/increased risk of dislocation = smaller/larger ROM
more downwards tilt = larger angle of Wilberg = less stress = increased risk of dislocation = smaller ROM
smaller angle of Wilberg = smaller/learger load bearing surface = decreased/increased risk of superior dislocation = smaller/larger ROM
smaller angle of Wilberg = smaller load bearing surface = increased risk of superior dislocation = larger ROM
what deepends the acetabulum
labrum
how does the femoral neck angulate
so that the head usually faces medially, superiorly, + anteriorly
what is the weakest part of the femur
neck
inclination angle
neck to shaft angle
-superior/inferior inclination
inclination angle decreases/increases with age
decreases
sex difference in inclination angle
generally smaller in females due to a more cantilevered neck
anteversion angle
anterior/posterior angulation
anteversion corresponds to internal/external rotation
internal
anteversion = toe in/out gait
toe in
retroversion corresponds to internal/external rotation
external rotation
retroversion = toe in/out gait
toe out
what do inclination angles focus
moment arm of the joint
coxa valga
pathologically high inclination angle
coxa vara
pathologically low inclination angle
does coxa valga/vara have a larger moment arm
coxa vara
-therefore generates more torque
what type of stress does the neck experience in coxa vara
torsional stress
what type of stress does the neck experience in coxa valga
compressional stress
what muscles attach onto the greater trochanter
abductor muscles
-mainly gluteus medius
coxa valga = smaller/larger moment arm = less/more force NEEDED to generate the same force as coxa vara
smaller moment arm = more force needed
does coxa vara/valga have a larger ROM
coxa valga
costs of coxa valga
-tends to cause higher joint reaction forces bearing down on articular cartilage of femoral head
-causes bending load since forces are all on one end
angle of anteversion/torsion
-intersection of the long axis of femoral head + transverse axis of the femoral condyles
-morphological torsion of femur from proximal to distal end
anteversion
pathologically high angle
anteversion is observed during coxa vara/valga
coxa valga
describe the gait of anteversion
toe in gait
retroversion
pathologically low angle
describe the gait of retroversion
-toe out gait
-external rotation during gait
what does toe in/out gait cause
abnormal ground reaction force positioning
toe in gait causes abductor/adductor moments at the knee + ankle
adductor
toe in gait problems
adductor moments at knee + ankle can over-compress medial compartment of knee, causing osteoarthitis
toe out gait problems
significantly compromised propulsion ability
closed chain exercises
has distal end of limb fixed to an immovable surface
2 examples of closed chain exercises
-squat
-push up
open chain exercises
involve movement of the distal end of the limb
2 examples of open chain exercises
-leg extension
-bicep curl
the hip complex movements are considered to be open/closed chain
closed chain
-walking, running, squatting
how many planes of closed chain mechanics for hip
3
name the 3 planes of closed chain mechanics for the hip
-sagittal
-transverse
-coronal
describe the fixed ends of the chain during a closed chain movement of the hip
-head + chest remain upright
-feet rooted to the floor
what is part of the closed chain system
-pelvic girdle
-lumbar spine
-ankle
-knees
-hip joints
sagittal plane motion of pelvis
anterior/posterior pelvic tilt
anterior pelvic tilt
brings ASIS anterior + inferior
-looks like back is arched
2 movements of anterior pelvic tilt
-hip flexion
-lumbar extension
posterior pelvic tilt
brings pubis up
2 movements of posterior pelvic tilt
-hip extension
-lumbar flexion
transverse plane motion of pelvis
pelvic rotation
left forward rotation
-medial rotation at right hip
-lumbar left rotation
-causes pidgin toed position (toe in) position corresponding to internal rotation of left hip
left backward rotation
-external rotation at right hip
-lumbar right rotation
-foot turned out
coronal plane motion of pelvis
lateral pelvic tilt
lateral pelvic tilt
-one hip joint serves as pivot point/axis
-opposite iliac crest elevates/drops
summary of pelvic motion
left hip drop:
-right hip ___
-left hip ___
-lumbar ___
-right hip adduction
-left hip abduction
-lumbar right lateral flexion
summary of pelvic motion
right hip drop:
-right hip ___
-left hip ___
-lumbar ___
-right hip abduction
-left hip adduction
-lumbar left lateral flexion
summary of pelvic motion
anterior pelvic tilt:
-right hip ___
-left hip ___
-lumbar ___
-right hip flexion
-left hip flexion
-lumbar extension
summary of pelvic motion
posterior pelvic tilt:
-right hip ___
-left hip ___
-lumbar ___
-right hip extension
-left hip extension
-lumbar flexion
summary of pelvic motion
left forward rotation (right foot planted):
-right hip ___
-left hip ___
-lumbar ___
-right hip medial rotation
-left hip open chain
-lumbar left rotation
summary of pelvic motion
left backward rotation (right foot planted):
-right hip ___
-left hip ___
-lumbar ___
-right hip lateral rotation
-left hip open chain
-lumbar right rotation
pelvifemoral rhythm
in order to maximize the ROM of the distal segment (femoral head), multiple joints are used
-similar to scapulohumeral rhythm of shoulder
describe the pelvifemoral rhythm of a squat’s butt wink
-posterior pelvic tilt that occurs at the bottom of the squat because you hit end ROM of hip flexion at the coxofemoral joint
-to go deeper after hitting end ROM of the ball + socket, you must posteriorly tilt the pelvis + flex the lumbar spine to maintained closed chain + keep balance
Tredelenberg gait
-lean towrads stance leg during single leg stance
-return to upright during double leg support
-produces trunk swaying (waddling)
Tredelenberg gait results from…
weak hip abductor muscles which cause pelvic drop
canes are used for…
weak abductor muscles
which side should a cane be used
contralateral side to the affected leg
why is using a cane on the contralateral side beneficial
-provides a counter torque to the force of gravity, reducing the need for the abductor muscle force
-maintains a neutral position of the pelvis in the frontal plane
-reduces the weight of the HAT
why is using a cane on the ipsilateral/same side bad
it helps the force of gravity because of same torque directions
-we don’t want this
is there any benefit to using a cane ipsilaterally
some benefit, but not ideal
-alleviates some of the body weight through the cane
osteokinematics
refers to bone movements of the joint about axes of rotation
-flex/ext, abd/add, internal/external rotation
arthrokinematics
refers to the movement at the articulating surfaces ot the joint
-rolling, spinning, gliding between contacting surfaces
arthrokinematics
rolling
-references roling without slip
-new points of contact are made between both surfaces as it rolls rightward on the flat surface
arthrokinematics
sliding/gliding
maintains 1 point of contact
arthrokinematics
rolling + sliding/gliding
-occur in opposite directions (rolls right, slides left)
-maintains translational position but changes orientation
what is the hip’s arthrokinematics
rolling + sliding/gliding
-the hip doesn’t roll out of its socket because it has both
arthrokinematics
spinning
maintains stationary point of contact + bone spins around an axis
concave
curved like the interior of a circle
convex
curved like the exterior of a circle
many joints of the body have what kind of relationship
concave-convex
we describe joints with regard to what the concave/convex surface is doing
convex
joint application of pure rolling without slip
would fall out of socket
joint application of rolling with slip
no dislocation would occur
flexing the knee gives the hip a lesser/greater ROM
greater
***for all the following osteokinematics, a muscle that supports a movement will LIMIT the opposing movement
primary + secondary muscles
hip flexion
1:
-iliopsoas
2:
-rectus femoris
-TFL
-sartorius
primary + secondary muscles
hip extension
1:
-gluteus maximus
2:
-semitendinosus
-semimembranosus
-biceps femoris long head
arthrokinematics for flexion/extension
pure spin about mediolateral axis of femoral head
abduction/adduction has a larger ROM
abduction (45-50 degrees)
abduction/adduction has a limited ROM
adduction (30 degrees)
primary + secondary muscles
hip abduction
1:
-gluteus medius
2:
-gluteus minimus
-TFL
primary + secondary muscles
hip adduction
1:
-adductor magnus
2:
-pectineus
-adductor longus
-adductor brevis
-gracilis
-obturator externus
adduction arthrokinematics
-inferior roll
-superior gliding
abduction arthrokinematics
-superior roll
-inferior gliding
describe ROM for internal + external rotation
ROM for both are similar
how is internal + external rotation usually measured
hip flexed 90 degrees
primary + secondary muscles
lateral (external) rotation
1:
-gluteus maximus
-piriformis
2:
-quadratus femoris
-obturator internus + externus
-gemellus superior + inferior
-sartorius
primary + secondary muscles
medial (internal) rotation
1:
-none
2:
-TFL
-gluteus minimus
-gluteus medius (anterior fibers)
internal rotation arthrokinematics
-anterior roll
-posterior glide
external rotation arthrokinematics
-posterior roll
-anterior gliding
Thomas test
lay down raise knee
-if lower thigh lifts = tight iliopsoas
-if knee extends = tight rectus femoris
closed chain movement for the hip causes which segment to move
pelvic movement, not femoral
Low inclination angle leads to…
Greater bending and shear loading in the neck of the femur
