Osteokinematics: Sagittal Plane Motions of the femur at
the hip joint
Flexion: 90o-135o
Extension: 0o-30o
Role of 2 joint muscles?
Osteokinematics: Frontal Plane Motions of the femur at
the hip joint
Abduction: 30o-50o
Adduction: 10o-30o
Role of 2 joint muscles?
Osteokinematics: Transverse Plane Motions of the femur at
the hip jointIR (extension*): 35o-45o
(Luttgens & Hamilton)IR (flexion**): 30o-45o
ER (extension*): 45o-50o
(Luttgens & Hamilton)ER (flexion**): 45o-60o
*Extension = Neutral -Terminal **Flexion = 900
Osteokinematicmotions of the femur at the hip joint during functional activities
*
**
D. Neumann – Kinesiology of the MS System
Hip Arthrokinematics
Osteokinematics: Sagittal plane Motions of the Pelvis at the Hip Joint
Osteokinematics: Frontal plane Motions of the Pelvis at the Hip Joint
Osteokinematics: Transverse Plane Motions of the Pelvis at the Hip Joint
Open Kinematic Chain Motions: LumboPelvic Rhythm
Closed Kinematic Chain MotionsThe system now strives
to keep the head & trunk upright
lumbar spine & pelvis motion will now generally be opposite of that during lumbar-pelvic rhythm
Acetabular Spatial OrientationFaces laterallyFaces anteriorly
18.5o males21.5o women
Faces inferiorly22o - 42o range38o in males35o in females
3 Acetabular Changes With Aging:
Ossification of the articulation of the three bones of the pelvisincreased “central stability”
Decreased acetabular “roundness”reduced co-aptation
Increased Central Edge Angleincreased superior stability
Structure of the Proximal FemurFemoral Head
more spherical than
acetabulum
fovea capitis
Spatial Orientation
Structure of the Proximal Femur: Angle of ?
Angle of InclinationFrontal plane angulation b/t the
shaft & neck of femurContributes to the normal
valgus position of the kneeDecreases with age
150o early infancy125o in adults120o in elderly
Abnormal Femoral Inclination Angle
Coxa ValgaIncrease leg length produces hip adductionIncrease “pre load” to hip abductorsDecrease moment arm of abductors
Coxa Vara leg length
Relative hip abduction
Poor hip abductor length tension relationship
Impingement may limit abduction ROM
Stress concentration superior contact area
Coxa Vara: congenital, developmental or traumatic
Structure of the Proximal Femur: Angle of ?
>15o Angle of Torsion or Version: Anteversion or Medial Femoral Torsion
Abnormal Angles of VersionEckoff DG: Orth Cl NA: 1994
Femoral anteversion decreases with ageBut if anteversion is excessive at birth it will
generally persist throughout lifetime
Excessive AnteversionIf uncompensated anteversion will expose significant amount of femoral head anteriorly
Excessive Anteversion
In order to improve congruency of joint surfaces lower extremity internal rotation may occur.
This may result in occur in “toed in” posture & gait.
Abnormal Angles of Version
If angle of version is less than 15o: Retroversion or Lateral Femoral Torsion
<15o Angle of Torsion or Version: Retroversion or Lateral Femoral Torsion
RetroversionIf uncompensated may
expose excessive head of femur posteriorly
To improve congruency, the LE may externally rotate and appear “toed out”
Position of Greatest Hip Congruency?
Combined position of:flexionabductionlateral rotation
Frequently used position for post hip dislocation immobilization
High compressive loads may be necessary to achieve maximum congruency
Is this closed pack position?
Position of Maximum Hip Congruency: Impact on Ligamentous Tension
Hip flexion, lateral rotation & abduction tends to “uncoil” supporting hip ligaments
Hip ligaments are tightened by extension
Frontal Plane Spatial Orientation of Hip and Stability?
Inferior angulation of acetabulum < the superior angulation of the femoral neck.
Therefore, a significant portion of the head remains uncovered.
This may lead to superior stability.
IliopsoasPsoas major is attached
to anterior lumbar vertebra
Iliacus is attached to iliac fossa
Tension within this group will group will “pull” lumbar curvature anteriorly increasing lumbar lordosis
Tensor Fascia Lata
Flexes & internally rotates hip Abducts if the hip is already
flexed Influence of the Thomas testMost important contribution of
TFL is maintaining tension in the ITB
Tensor Fascia LataITB is considered to assist in
relieving the femur of some of the tensile loads on the shaft.
TFL (along with gluteus max) has a roll in “taking up the slack” in the ITB to enhance this function
Possible role in muscle imbalances at hip
Gluteus mediusAsynchronous function of three parts
anteriormiddleposterior
All fibers abductAnt. fibers flex & IRPost. fibers extend & ERPossible role in muscle imbalances at
the hipTrochanteric Bursa
AdductorsPeak isometric
torque exceeds that of abductors
Attachment to pubic ramus may be clinically significant.
Gracilis is the only adductor to cross the knee
Medial Hip RotatorsThere is no muscle with a primary
function of hip medial rotation Muscles with lines of pull anterior to
the hip joint axis at some point of the ROM may contribute to the activity
TFL & anterior gluteus medius may be the most significant of these.
Unilateral Stance Ipsilateral Trunk List
Ipsilateral Cane Contralateral Cane
Impact of a Carried Load: Contralateral Upper Extremity
EMG of hip abductor muscles increased16.8% at 5% BW load38.9% at 10% BW
load58.4% at 15% BW
loadNeumann D, PT 76: 1320-1330, 1996
EMG of hip abductor muscles decreased10.6% at 5% BW
load16.9% at 10% BW
load17% at 15% BW
loadNeumann D, PT 76: 1320-1330, 1996
Impact of a Carried Load: Ipsilateral Upper Extremity