Biomechanics of Spine.pptx

7/25/2019 Biomechanics of Spine.pptx

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Biomechanics of theLumbar Spine

Dr.Sameera Rasool

DPT (TUF)

MSc (UK)


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b!ecti"e

Today we will learn about Lumber ligament Spinal curves

Abnormal spinal curvature Movements of spine Muscles of spine


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3

Ma!or Lumbar Li#aments

Herzog Fig 2!3

ALL" Anterior Longitudinal Ligament#LL" #osterior Longitudinal Ligament

LF$ Li#amentum Fla"um$SF" $nterSpinous LigamentSSL" SupraSpinous Ligament


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#owerful anterior longitudinal ligament and t%e wea&er

posterior longitudinal ligament connect t%e vertebralbodies in t%e cervical' t%oracic' and lumbar regions(

T%e supraspinous ligament attac%es to t%e spinousprocesses t%roug%out t%e lengt% of t%e spine( T%isligament is prominently enlarged in t%e cervicalregion' w%ere it is referred to as t%e ligamentumnuchae, or ligament of the neck.

$nterspinous ligaments' t%e intertransverse ligaments'and

t%e ligamenta )ava ' responsible for connectionsbetween spinous processes' transverse processes' andlaminae(

Ma!or Lumbar Li#aments


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Li#amentum nuchae


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Ligamentum )avum' connects t%e laminae of

ad*acent vertebrae( Most spinal ligaments are composed of collagen

+bers t%at stretc% minimally' t%e ligamentum)avum contains a %ig% proportion of elastic +bers'

w%ic% lengt%en during spinal )e,ion and s%ortenduring spinal e,tension(

Prestress Ligamentum )avum is in tension even w%en t%e

spine is in anatomical position' en%ancing spinalstability( T%is tension creates a slig%t' constantcompression in t%e intervertebral discs' referred toas prestress(


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Spine contains four normal curves

primar% cur"esT%oracic and sacral curves' w%ic% are

concave anteriorly' are present at birt%(

Secon&r% spinal cur"eT%e lumbar and cervical curves' w%ic% are

concave posteriorly ' develop fromsupporting t%e body in an uprig%t position

after young c%ildren begin to sit up andstand( Since t%ese curves are not present atbirt%(

Spinal 'ur"es


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T%e cervical and t%oracic curves c%angelittle during t%e growt% years' t%e curvatureof t%e lumbar spine increases appro,imately!-. between t%e ages of / and !/

'on&ition aectin# spinal cur"es Heredity #at%ological conditions An individual0s mental state T%e forces to w%ic% t%e spine is %abitually

sub*ected( 1urves enable t%e spine to absorb more

s%oc& wit%out in*ury(


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,aggeration of t%e lumbar curve' or lordosis

often associated wit% wea&ened abdominalmuscles and anterior pelvic tilt(

'auses congenital spinal deformity

wea&ness of t%e abdominal muscles poor postural %abits overtraining in sports re4uiring repeated

lumbar %ypere,tension' suc% as gymnastics'+gure s&ating' *avelin t%rowing' andswimming t%e butter)y stro&e(

lor&osis


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Limited range of motion in %ip e,tension isassociated wit% lumbar lordosis

5besity causes reduced range of motion oft%e entire spine and pelvis' resultingly

increased anterior pelvic tilt and anassociated wit% lumbar lordosis Anterior tilt and lordosis are greater during

running t%an during wal&ing

lordosis places compressive stress on t%eposterior elements of t%e spine and is a ris&factor for low bac& pain(

'auses


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,aggerated t%oracic curvature incidence 6. in t%e general population'

wit% e4ual distribution across genders

K%phosis


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congenital abnormality #at%ology suc% as osteoporosis Sc%euermann0s disease( Sc%euermann0s disease develops

between t%e ages of !- and !7 years 8ot% genetic and biomec%anical

factors are believed to play a role

Swimmers back because seen in adolescents w%o %ave trained

%eavily wit% t%e butter)y stro&e

'auses


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Treatment for mil& cases ma% consistof

,ercises to strengt%en t%e posteriort%oracic muscles'

Treatment for se"ere cases 8racing surgical corrections

Treatment


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Lateral deviation in spinal curvature(T%e lateral deformity is coupled wit%

rotational deformity of t%e involvedvertebrae

1ondition ranging from mild to severe( Scoliosis may appear as eit%er a 1 or an S

curve

$nvolving t%e t%oracic spine' t%e lumbarspine' or bot%

Scoliosis


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Structural scoliosis Structural scoliosis involves in)e,ible

curvature t%at persists even wit% lateralbending of t%e spine(

*onstructural scoliosis 1urves are )e,ible and are corrected wit%

lateral bending(

T%pes


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1ongenital abnormalities

cancers( 9onstructural scoliosis may occur

secondary to a leg lengt% discrepancy orlocal in)ammation(

Small lateral deviations in curvature arecommon and may result from a %abit suc%as carrying boo&s or a %eavy purse on oneside of t%e body every day(

Appro,imately /-:;-. of all scoliosis'termed idiopathic

'auses


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$diopat%ic scoliosis commonly diagnosedbetween t%e ages of !- !3 years' but canbe seen at any age(

#resent in 2:


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Mil& scoliosis

Symptoms vary wit% t%e severity( Mild cases may be nonsymptomatic

Treatment May selfcorrect wit% Time Stretc%ing and strengt%ening

Se"ere scoliosis ,treme lateral deviation and localized rotation of

t%e spine' can be painful and deforming'

Treatment bracing surgery

S%mptoms an& treatment


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bnormal spinal cur"ature


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Spine allows motion in all t%ree planes ofmovement Spinal movements always involve a number

of motion segments(

T%e range of motion =>5M? allowed at eac%motion segment is depend on anatomicalconstraints t%at vary t%roug% t%e cervical'

t%oracic' and lumbar regions of t%e spine(

M,-M-*TS F T- SP+*-


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Mo"ements of the Spine

Fle,ion ,tension Hypere,tension

Lateral Fle,ion >otation


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T%e >5M for )e,ion@e,tension considerablein t%e cervical and lumbar regions !/ at t%e 1B17 vertebral *oint and 2- at

LBS!(

$n t%e t%oracic spine 'due to t%e orientationof t%e facets' t%e >5M increases fromappro,imately


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$t is important not to confuse spinal )e,ion wit% %ip

)e,ion or anterior pelvic tilt' alt%oug% all t%reemotions occur in activity suc% as touc%ing t%e toes(

Hip )e,ion consists of anteriorly directed sagittal

plane rotation of t%e femur wit% respect to t%e pelvicgirdle

anterior pelvic tilt is anteriorly directed movementof t%e AS$S wit% respect to t%e pubic symp%ysis(

Cust as anterior pelvic tilt facilitates %ip )e,ion' alsopromotes spinal )e,ion


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,tension of t%e spine bac&ward past anatomicalposition is termed hyperextension.

The ROM for spinal hyperextension isconsiderable in cervical and lumbar regions(

Lumbar %ypere,tension is re4uired for e,ecutionof many sport s&ills' including several swimmingstro&es' t%e %ig% *ump and pole vault' andnumerous gymnastic s&ills(

For e,ample' during t%e e,ecution of a bac&%andspring' t%e curvature normally present int%e lower lumbar region may increase twentyfold

%pere/tension


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L t l Fl i &


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Frontal plane movement of t%e spine away from

anatomical position is termed lateral exion.

The largest ROM for lateral exion occurs in thecervical region' ;:!- of motion allowed at 1


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Spinal rotation in t%e transverse plane is again

freest in t%e cervical region of t%e spine !2 of motion allowed at 1!12( $t is ne,t freest in t%e t%oracic region' ; of

rotation is permitted among upper segments(

From T/T6 downward' t%e range decreases only 2 of motion allowed in t%e lumbar spine

due to t%e interloc&ing of t%e articularprocesess(

At lumbosacral *oint' rotation allowed is B( Structure of t%e spine causes lateral )e,ion

and rotation to be coupled(

Rotation


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Muscles of the Spine

Muscles of nec& and trun& named in pairs'wit% one on t%e left and t%e ot%er on t%erig%t side of body

Anterior Aspect #osterior Aspect Lateral Aspect


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nterior spect Ma*or anterior muscle groups of t%e cervical

region are t%e prevertebral muscles' including >ectus capitis anterior >ectus capitis lateralis'

Longus capitis' and longus colli ig%t pairs of %yoid muscles 8ilateral tension development results in )e,ion

of %ead(

Dnilateral tension development in prevertebralscontributes to" lateral )e,ion of %ead toward contracting muscles or'

to rotation of %ead away from contracting muscles


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Abdominal muscles are t%e>ectus abdominis'

,ternal obli4ues' and t%e internal obli4ues (8ilaterally' t%ese are ma*or spinal )e,ors and reduceanterior pelvic tilt(Dnilaterally t%e muscles produces lateral )e,ion of t%espine toward t%e tensed muscles(

$nternal obli4ues causes rotation of t%e spine towards t%esame side(,ternal obli4ues results in rotation toward t%e oppositeside($f t%e spine is +,ed' t%e internal obli4ues produce pelvic

rotation toward t%e opposite side' wit% t%e e,ternal'obli4uesproducing rotation of t%e pelvis toward t%e same side(T%ese muscles also form t%e ma*or part of t%e abdominalwall' w%ic% protects t%e internal organs of t%e abdomen(

b&ominals


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Posterior spect

#rimary cervical e,tensors" splenius capitis

splenius cervicis

T%oracic and Lumbar Muscle groups" erector spinae

Semispinalis

deep spinal muscles


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T%e muscles of t%e erector spinae group aret%e ma*or e,tensors and %ypere,tensors oft%e trun&(

8ilaterally all posterior trun& musclescontribute to e,tension and %ypere,tension

Dnilaterally contribute in lateral )e,ion


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Lateral spect

Many muscles of nec& and trun& causelateral )e,ion w%en contracting unilaterally'but eit%er )e,ion or e,tension w%encontracting bilaterally(

Muscles" sternocleidomastoid levator scapulae scalenus anterior' posterior and medius Lumbar region" 4uadratus lumborum'

psoas ma*or


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Biomechanics of Spine.pptx

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