Ch. 12 Hip (Neumann) Flashcards
How do alignment issues effect hip?
change the way the femoral head sits in the acetabulum
What is the angle of inclination at birth?
What is the optimal angle of inclination in adults?
Alignment Issues (2)?
Birth: 140-150 degrees; angle decreases when child becomes WB Adults: 125 degrees Alignment issues: - Coxa vara= angle too small -Coxa valga= angle too large
Normal Torsion Angle
excessive torsion angles (2)
normal= 10-15 degrees of anteversion excessive anteversion >10-15 - in toeing retroversion <10-15 - out toeing (seen in pitchers & dancers)
clinical implications of in-toeing
- how people compensate for excessive anteversion
- problem at proximal hip (NOT foot/ankle)
- can only be corrected b4 growth plates close
- overtime develop shortened IRs–> decreased ER
Blood supply to femoral head
obturator artery gives a small/inconsistent blood supply
Acetabular Labrum Ring
- made of fibrocartilage (compressive forces)
- deepens socket
- femoral head contacts acetabulum only along lunate surface
Iliofemoral (Y) ligament
- AIIS to intertrochanteric line
- taut w full hip extension & ER (lateral portion)
- important stabilizing force for preventing further hip Ext.
Ischiofemoral ligament
- ischium to greater trochanter
- superficial fibers taut w IR & hip ext
- sup fibers taut w add
- inf fibers taut flexion
Pubofemoral ligament
- ant/inf rim of acetabulum & sup pubic ramus to medial fibers of iliofemoral lig
- taut w ext & abd
Closed packed position of hip
congruency?
closed packed= hip ext, abd, IR (NOT position of max congruency)
max congruency= hip flexion 90, abd, ER (tailors sit)
- max congruency= best position for mobilizing
- little passive tension to the ligaments in this position
Femoral-on-hip Osteokinematics
Open-Chain (flexion)
knee bent vs. straight?
Flexion:
- full hip flexion w knee bent= 120
- 80 w knee straight bc of passive insufficiency of hamstrings
- full hip flexion slackens most ligaments, but stretches inferior capsule
Femoral-on-hip Osteokinematics
Open-Chain (extension)
knee bent vs. straight
- full extension= 20 deg beyond neutral w knee straight
- less with knee bent bc of passive insufficiency of quads
- stretches all ligaments and hip flexors
Femoral-on-hip Osteokinematics
Open-Chain (abduction)
limited by?
- measures 40 deg
- limited by tension in pubofemoral ligament, adductors, hamstrings
Femoral-on-hip Osteokinematics
Open-Chain (adduction)
limited by?
- 25 degrees beyond neutral
- limited by hip abds, contralateral limb, sup fibers of ischiofemoral lig
Femoral-on-hip Osteokinematics
Open-Chain (IR)
limited by?
- 35 degrees unchanged by flexion/ extension of hip
- limited by piriformis & parts of ischiofemoral lig
