Pelvic Acadimya

8/3/2019 Pelvic Acadimya

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The Pelvic GirdleThe Pelvic Girdle

Dr Masharawi YoussefDr Masharawi Youssef


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LumboLumbo sacralsacral

JointJoint

SacroSacro iliac J.iliac J.

Hip J.Hip J.


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Form ClosureForm Closure Shape of the jointShape of the joint

Irregularity of theIrregularity of the

joint cartilagejoint cartilage

Ridges and groovesRidges and groovesSchematic representation of formSchematic representation of form

closureclosure

((SnejdersSnejders et al 1993a)et al 1993a)


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Force ClosureForce Closure

Roman archRoman arch

principleprinciple

Ligaments andLigaments and

MusclesMuscles

compressioncompression

**Mobility Vs StabilityMobility Vs Stability

SnejdersSnejders et al 1993aet al 1993a


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Interosseous ligament

Short dorsal sacroiliac

ligament

Sacrotuberous ligament

Long dorsal sacroiliacligament


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Form closure - Force closure

Self-locking mechanism

Musculature Ligaments

Longit. string Post. string Ant. oblique

Sacrotuberous

Long dorsal

sacroiliac

M.L.

ThoracolumbarFascia

Biceps (long

head)

Latis.Dors.

Glut.Max.

E.O.

I.O.

T.A.P.F.

Interosseous

Short dorsal

E.Sp.

ITB


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Thoracolumbar FasciaThoracolumbar Fascia

Attachment for :Attachment for : LatissimusLatissimus DorsiDorsi

GluteusGluteus MaximusMaximus

TrapeziusTrapezius musclesmuscles

T.A. & I.O.T.A. & I.O.

L.ML.M SacrotuberousSacrotuberous liglig..


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Insufficient SelfInsufficient Self--lockinglocking

Ligament laxityLigament laxity

Capsular laxityCapsular laxity

Reduced muscle strengthReduced muscle strength Poor muscle coPoor muscle co--ordinationordination


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Insufficient SelfInsufficient Self--lockinglocking

Unusual positioning in SIUnusual positioning in SI liglig. & capsule. & capsule

Source of painSource of pain

HypermobilityHypermobility Vs.Vs.

HypomobilityHypomobility

Excessive loadsExcessive loads

on surrounding structureson surrounding structures

AbnormalAbnormal

afferent outputafferent output

Affect motorAffect motor

programprogram


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BiomechanicsBiomechanicsIn Lx. FlexionIn Lx. Flexion

SacralSacral nutationnutation

Anterior rotation +Anterior rotation + outflareoutflare ofofiliumilium Hip flexionHip flexion

In Lx. ExtensionIn Lx. Extension Minimal CN followed by SacralMinimal CN followed by Sacral nutationnutation

Posterior rotation +Posterior rotation + inflareinflare ofofiliumilium

Hip extensionHip extension


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BiomechanicsBiomechanics

In leg Flex.In leg Flex.

Sacral torsionSacral torsion Posterior rotation ofPosterior rotation ofiliumilium

In leg Ext.In leg Ext.

Sacral torsionSacral torsion

Anterior rotation ofAnterior rotation ofiliumilium

* Sacral* Sacral nutationnutation increase force closure (closeincrease force closure (close

pack)pack)


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The Hip Joint:The Hip Joint:Anatomical and biomechanical aspectsAnatomical and biomechanical aspects


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Stability of the Hip (cont.)Stability of the Hip (cont.)

The orientation of theThe orientation of the

bonybonytrabeculaetrabeculaewithinwithinthe pelvic girdlethe pelvic girdle

corresponds to the linescorresponds to the lines

ofof force met in bothforce met in bothstatic and dynamicstatic and dynamic

functionfunction


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The spreading of theThe spreading of the acetabulumacetabulum

and labrumand labrum

Occurs under load is thought to maximize theOccurs under load is thought to maximize the

surface contact area.surface contact area.

This diminishes the force per unit area and moreThis diminishes the force per unit area and moreevenly distributes total contact pressure area.evenly distributes total contact pressure area.

This ability is age dependent = becomesThis ability is age dependent = becomesnarrower and the contact stresses greater.narrower and the contact stresses greater.


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The shortThe short periarticularperiarticular musclesmuscles ((piriformispiriformis,, obturatorobturator

externusexternus,, obturatorobturator internusinternus)) act as postural muscles andact as postural muscles andstabilizers (reinforce capsule rather than act asstabilizers (reinforce capsule rather than act as

prime movers).prime movers).


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Lateral muscles (Lateral muscles (gluteusgluteus medius/minimusmedius/minimus, tensor fascia, tensor fascia latalata) in) in

balance with adductors are important inbalance with adductors are important inmaintaining level of pelvis during locomotion.maintaining level of pelvis during locomotion.

AnteriorlyAnteriorlyiliopsoasiliopsoas has a role in support of thehas a role in support of the

capsule in an area deficient of ligaments.capsule in an area deficient of ligaments.


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Angles of inclination andAngles of inclination and anteversionanteversion

--In adults the neck forms an angle of ~ 125In adults the neck forms an angle of ~ 125

angle ofangle ofdegrees with the shaft of the femur (degrees with the shaft of the femur (30 degrees with30 degrees with--) and an angle of 10) and an angle of 10inclinationinclination

).).anteversionanteversionthe frontal plane (angle ofthe frontal plane (angle of


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AnteversionAnteversion A decrease in angle ofA decrease in angle of

anteversionanteversion may result in amay result in alateral rotation profile.lateral rotation profile.

An increase in angle ofAn increase in angle ofanteversionanteversion may result in amay result in a

medial rotation profile.medial rotation profile.


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YY--IliofemoralIliofemoral andandpubofemoralpubofemoral

ligamentsligaments

YY--ligtligt.: A strong ligament, which reinforces the.: A strong ligament, which reinforces the

anterior aspect of the hip.anterior aspect of the hip. The tendon ofThe tendon ofpsoaspsoas major crosses at this point,major crosses at this point,

which increases dynamic support.which increases dynamic support.


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IschioIschio--femoral ligamentfemoral ligament


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The inguinal areaThe inguinal area

the femoral trianglethe femoral triangle

Boundaries:Boundaries:

-- superior: inguinalsuperior: inguinal liglig..-- Lateral:Lateral: sartoriussartorius

-- Medial: adductorMedial: adductor magnusmagnus

-- Floor:Floor:

-- LateralLateral--ilipsoasilipsoas

-- PectineusPectineus

-- AdductorAdductor longuslongus


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The movements of the femur relative toThe movements of the femur relative to

thethe iliumilium are not pureare not pure

In NWB include flexion/abduction/lateralIn NWB include flexion/abduction/lateral

rotation, and extension/adduction and medialrotation, and extension/adduction and medialrotationrotation

During gait;During gait;

flexion/adduction/lateral rotationflexion/adduction/lateral rotation

extension/abduction/medial rotation (close packedextension/abduction/medial rotation (close packedposition).position).


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Forces of the hip in single leg stanceForces of the hip in single leg stance..

G, Center of gravity; M,G, Center of gravity; M,

muscle forces;muscle forces; K, effect of partial bodyK, effect of partial body

weight;weight;

R, resultant vectorR, resultant vector


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Single leg stance = eccentric loadSingle leg stance = eccentric load the effective center ofthe effective center of

gravity moves distallygravity moves distallyand away from theand away from thesupporting leg sincesupporting leg since

the nonthe non--supporting leg issupporting leg isnow calculated as part ofnow calculated as part ofthe body mass actingthe body mass acting

upon the weightupon the weight--bearingbearinghip.hip.


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Single leg stanceSingle leg stance-- compressive forcescompressive forces

Since the loading of the hipSince the loading of the hip in the single legin the single leg

stance phase of gaitstance phase of gait is a multiple of body weightis a multiple of body weight,,increases in body weight will have a particularlyincreases in body weight will have a particularly

deleterious effect on the totaldeleterious effect on the total compressivecompressive

forcesforces applied to the jointapplied to the joint


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The effect of body weight andThe effect of body weight and

equilibriumequilibrium

The effect of this combined loading of bodyThe effect of this combined loading of body

weight and the abductor muscle responseweight and the abductor muscle responserequired for equilibrium results in the loading ofrequired for equilibrium results in the loading of

the femoral head to approximatelythe femoral head to approximately4 times4 times

body weightbody weight during the single leg stance phaseduring the single leg stance phaseof gaitof gait


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The use of a can (cont.)The use of a can (cont.) only 9 kg of force applied to a caneonly 9 kg of force applied to a cane in thein the

opposite hand reduces the load on the femoralopposite hand reduces the load on the femoralhead by nearly 40%head by nearly 40%

The same effect could also be achieved by aThe same effect could also be achieved by a

40% reduction in body weight40% reduction in body weight

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Pelvic Acadimya

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