hip Flashcards
Classify the hip joint
-diarthrodial
ball and socket
3 degrees of freedom
How does the acetabulum face
-faces laterally, slightly inferior and anterior
-anteversion: silt anterior tilt (too much will make it unstable)
what fraction of the acetabulum does the pelvic bones make up?
ilium: 2/5
ischium: 2/5
pubis 1/5
acetabulum articular cartailge
horseshoe shaped at the WB parts of the joint (superiorly to posteriorly)
center edge angle/angle of Wilberg
how much of the acetabulum is present to cover the femur
-35-40%
-men are closer to 40% and wormen are closer to 35%
-anything less than 35% puts you at more of a risk of dislocation
acetabuluar labrum
goes around the periferi to deepen the socket
What is the normal angulation of the femur head to the shaft
125
-140-150 at birth but decreases as the baby starts to WB
coxa valga
when the angulation of the femur head to the shaft is >125
-causes genu vara (knee varus)
coxa vara
when the angulation of the femur to the shaft is <125
-causes genu valgus
Femoral head angle of torsion
10-15 normal anteversion
-positioned forward (anterior to frontal plane)
-anything below 10 anteversion is considered retroversion of the femoral head
excessive anteversion
greater than 15
IR hip so head is firm in the acetabulum and stand with toes pointed in
retroversion
less than 10 anteversion
-ER the hip so head is firm in the acetabulum and stand with toes out
when is the hip joint congruent
when the hip is flexed 30, abd 30 and slightly ER
What are the hip joint ligaments
-capsule:
-iliofemor
-pbofemoral
-ischiofemoral
hip joint capsule
thick superiorly and acts as sleeve
iliofemoral ligament
AIIS to intertrochantic line
-shaped like an inverted Y
-taut in ER and Ext
pubofemoral
pubic ramus to intertrochanteric fossa
-taut in Ext. ER. and abuction
ligamentum teres
fovea of the femur to the acetabulum
-protects the obturator artery
-as the acetabulum moves superiorly the ligament acts as a sling and tenses up to give inferior support
-as you move through ROM is distributes synovial fluid
ischiofemoral
ischial tuberosity to the GT
-limits flexion, extension, IR, Add
Closed pack position and open pack position of the hip joint
close pack: extension (all ligaments are taut)
open pack: flexion - joints are more congruent however
arthrokinematics for the hip joint NWB
-flexion/extension: spinning
-abduction/adduction: upward roll and downward glide or downward roll and upward glide
ER/IR: posterior roll and anterior glide or anterior roll and posterior glide
WB roll and glide are in same direction
Osteokinematics of the hip joint PROM
flexion: 0-80 (knee ext)/0-120 (knee flexed)
extension: 0-20 (knee ext)/0 (knee flexed)
abduction: 0-40
adduction: 0-25
ER: 0-45
IR: 0-35
limits to flexion
-tight glute max and inferior joint capsule
limits to extension
anterior structures
-pubiofemor ligament
ischiofemoral ligament
iliofemoral ligament
limits to abduction
-adductors
-pubofemoral ligaments
limits to adduction
abductors
-ischiofemoral
-lateral hip muscles like glute med
limits to IR
ischiofemoral ligament
ER muscles
limits to ER
iliofemroal
pubiofemoral
What osteokinematics are required for gait (hip)
flexion: 0-30 needed for terminal swing
extension: 0-10 needed for terminal stance
IR: 0-5 when in stance and advancing other limb
ER: 0-5 when advancing the limb
pelvic osteokinematics
anterior/posterior pelvic tilt (sagittal plane)
lateral pelvic tilt - add of hip
pelvic rotation - transverse plane
gender differences in pelvis
females: have a more cylindrical shape
males: have a taller and more conical shape
ground reactive force force line and management
heel to COM is the force line
-musculature help to manage it
joint reactive force
-force across the surface of the joint
-from head of the femur to acetabulum
-tightness of muscles add compression and so does gravity
hip flexors *= primary
*iliopsas
*rectus femoris
-sartorius
-TFL
-pectineus
-adductor longus
-adductor brevis, gracilus and gluteus min anterior fibers
(glute med can assist)
hip extensors *=primary
*glute maximus
-biceps femoris
-semitendinosus
-semimebranosus
-adductor magnus
-posterior fibers of glute med
Hip Abductors
-their contribution to gait
-pass superior to Anterior posterior axis
- Gluteus medius*
-gluteus minimus
-TFL
-piriformis
-sartorius
- control frontal plane hip drop during gait
- Ground reaction force causes an adduction force and an abduction internal moment to counter it
Hip adductors
-their contribution to gait
-inferior to the anterior posterior axis
-gracilis*
-pectineus*
-adductor, longus, Magnus and brevis *
-biceps femoris
-gluteus maximus
-quadratus femoris
-gait: work eccentrically during weight acceptance on the leg that you are leaving and concentrically during weight acceptance during the leg that you are going to
Hip ER
-contribution to gait
posterior to vertical axis
-gluteus Maximus*
-quadratus femoris
-GOGO
-piriformis
-gluteus medius (posterior fibers)
-gluteus minimus (posterior fibers)
-gait: initial contact to loading response – femur IR to absorb shock so ER decelerate the limb
Hip IR muscles
anterior to vertical axis
-gluteus medius (anterior fibers)*
-gluteus minimus (anterior fibers)*
-TFL*
-pectineus
-adductor longus
-adductor brevis
-gait: advance pelvis during swing
What groups are stronger
-Extensors
-flexors
-adductors
-abductors
-IR
-ER
Adductor longus
- during hip flexion its a hip extensor
-during hip extension its a hip flexor
Why do people with weak abductors/painful hip have a compensatory lateral trunk lean towards the weak side
it decreases the joint reaction force and therefore the force at the hip overall
-using a cane will also help with joint reaction forces in the contralateral hand
