Pelvis and Hip Part 2 Flashcards
Iliofemoral limits
Extension, ER
Pubofemoral
Hip ABD and Extension
Ischiofemoral
Extension
IR
- Iliofemoral Ligament
- Assists gait of
paraplegic
with only Knee/ankle/foot orthoses and leaning posterior, iliofemoral ligaments
stabilize the hips for gait
Hip Axis of Rotation/Joint Center:
- Assumed to be center of femoral head
- Reasonable estimate for nearly spherical head
- Reasonable for flex/ext
Consider IR/ER occurring around vertical axis running through center of femoral head
- It would also run through the center of the knee
Axis is also influenced by
anterior bowing of femoral shaft
The longitudinal axis for rotation would actually be
extramedullary
Hip max congruency
90 deg flexion
moderate abduction and ER
Close Pack
Full extension with slight int rotation & abduction
Capsular Pattern of the Hip
Flexion > Abduction > Medial Rotation
sometimes medial rotation has greatest limitation
Hip sagittal plane motion
flexion ext
Pelvis on femur
- anterior/posterior tilt
Frontal plane Hip motion
abduction/adduction
Pelvis on femur
Contralateral hip hike/drop =Pelvic Ab/Adduction on Femur
Transverse Plane Hip Motions
Internal/external rotation
Pelvis on femur
Pelvis rotation CW/CCW (superior view) = Pelvic IR/ER on Femur
- Anterior Pelvic Tilt AKA - Pelvic on Femoral Hip Flexion
- A force couple action of
Anterior hip flexors (sartorius too) &- Posterior L/S extensors
anterior pelvic tilt must be counterbalanced by the
rectus abdominis stabilizing the pelvis & lumbar spine
- Posterior Pelvic TiltPelvic on Femoral Hip Extension
Force couple action of
Rectus Abdominis
Hip extensors (gluteus maximus & hamstrings)
- Problems of Hip Flexion Contracture
- common with
Excessive sitting without exercise interruption.
Disorders of hip flexor spasticity
Painful/inflamed hip joints
Adaptive shortening then follows
Problems of Hip Flexion Contracture
Disrupts
normal biomechanics of walking & standing
- Standing could be passive via
- via Y ligament suspension & leaning back, but
HFC requires active stabilization/energy demand
- Hip Adductors: Dual Sagittal Plane Function
- A) From a position of hip flexion
adductor longus extends the hip, assisted by adductor magnus
Hip Adductors: Dual Sagittal Plane Function
From a position of hip extension
adductor longus flexes the hip, assisted by rectus femoris
R IRs rotate the pelvis _____ on the stance femur during the first 30% of gait cycle
CW
Secondary IRs (No Primary)
Longus
Glute med/min
TFL
Most of the hip adductors are also
IRs
- Hip Extensor Control of Trunk Forward Lean
- Subtle forward lean recruits
glut max, hamstrings & adductor magnus
After subtle forward lean
glut max gets quiet and hamstrings & adductor magnus increase
- Ant Pelvic tilt increase torque arm of
hamstrings while reducing it for
glut max
Femoral on Pelvic Hip Extension
Hip extensors & adductors (from hip flex position)
Femoral on Pelvic Hip Extension
Lumbar spine extensors support the flexed trunk posture &
stabilize the pelvis (required for foundation of hip extensors)
- Hip Abductors and Trendelenberg
- Hip Abductor Function:
Little functional need to abduct femur on pelvis
Stabilizing pelvis abduction on stance femur = focus
- Trendelenberg Sign
- a functional test of
abductor strength
+ Trendelenburg
contralateral pelvis drops due to abductor weakness on stance side
Trendelenberg (compensatory) Gait:
Trunk shifts over stance side to bring CG over stance leg (within base of support)
Will see ”wobble” gait
Hip Abductors Contribution
Gluteus Medius
- 60-65% CSA
Gluteus Minimus
- 20-30% CSA
TFL
- 4-10% CSA
Function and Stretching of Piriformis
Hip Extended
external rotator stretched during IR
Function and Stretching of Piriformis
Hip Flexed
an Internal rotator stretched during ER
Tightness of Piriformis muscles
May limit ______
May compress the ______
IR
Sciatic Nerve
Tightness of Piriformis muscles
Could cause abnormal stress on
SI Joint
Tightness of Piriformis muscles
May cause buttock pain with radiation of pain into the
hip, posterior thigh, or proximal lower leg
- With right leg fixed in stance – in preparation for Cutting to the Left:
- Contraction of R external rotators turns the L pelvis to the
left (CCW from above)
For abrupt Change of Direction
- Uses glut max (w/ simultaneous hip extension) + the short external rotators:piriformis, obturator internus, gemellus superior, gemellus inferior, quadratus femoris, & obturator externus
