7/25/2019 Biomechanics of Spine.pptx
1/41
Biomechanics of theLumbar Spine
Dr.Sameera Rasool
DPT (TUF)
MSc (UK)
7/25/2019 Biomechanics of Spine.pptx
2/41
b!ecti"e
Today we will learn about Lumber ligament Spinal curves
Abnormal spinal curvature Movements of spine Muscles of spine
7/25/2019 Biomechanics of Spine.pptx
3/41
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
7/25/2019 Biomechanics of Spine.pptx
4/41
#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
7/25/2019 Biomechanics of Spine.pptx
5/41
Li#amentum nuchae
7/25/2019 Biomechanics of Spine.pptx
6/41
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(
7/25/2019 Biomechanics of Spine.pptx
7/41
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
7/25/2019 Biomechanics of Spine.pptx
8/41
7/25/2019 Biomechanics of Spine.pptx
9/41
7/25/2019 Biomechanics of Spine.pptx
10/41
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(
7/25/2019 Biomechanics of Spine.pptx
11/41
7/25/2019 Biomechanics of Spine.pptx
12/41
7/25/2019 Biomechanics of Spine.pptx
13/41
,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
7/25/2019 Biomechanics of Spine.pptx
14/41
7/25/2019 Biomechanics of Spine.pptx
15/41
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
7/25/2019 Biomechanics of Spine.pptx
16/41
,aggerated t%oracic curvature incidence 6. in t%e general population'
wit% e4ual distribution across genders
K%phosis
7/25/2019 Biomechanics of Spine.pptx
17/41
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
7/25/2019 Biomechanics of Spine.pptx
18/41
7/25/2019 Biomechanics of Spine.pptx
19/41
Treatment for mil& cases ma% consistof
,ercises to strengt%en t%e posteriort%oracic muscles'
Treatment for se"ere cases 8racing surgical corrections
Treatment
7/25/2019 Biomechanics of Spine.pptx
20/41
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
7/25/2019 Biomechanics of Spine.pptx
21/41
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
7/25/2019 Biomechanics of Spine.pptx
22/41
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
7/25/2019 Biomechanics of Spine.pptx
23/41
$diopat%ic scoliosis commonly diagnosedbetween t%e ages of !- !3 years' but canbe seen at any age(
#resent in 2:
7/25/2019 Biomechanics of Spine.pptx
24/41
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
7/25/2019 Biomechanics of Spine.pptx
25/41
bnormal spinal cur"ature
7/25/2019 Biomechanics of Spine.pptx
26/41
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+*-
7/25/2019 Biomechanics of Spine.pptx
27/41
Mo"ements of the Spine
Fle,ion ,tension Hypere,tension
Lateral Fle,ion >otation
7/25/2019 Biomechanics of Spine.pptx
28/41
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
7/25/2019 Biomechanics of Spine.pptx
29/41
$t is important not to confuse spinal )e,ion wit% %ip
)e,ion or anterior pelvic tilt' alt%oug% all t%reemotions occur in activity suc% as touc%ing t%e toes(
Hip )e,ion consists of anteriorly directed sagittal
plane rotation of t%e femur wit% respect to t%e pelvicgirdle
anterior pelvic tilt is anteriorly directed movementof t%e AS$S wit% respect to t%e pubic symp%ysis(
Cust as anterior pelvic tilt facilitates %ip )e,ion' alsopromotes spinal )e,ion
7/25/2019 Biomechanics of Spine.pptx
30/41
7/25/2019 Biomechanics of Spine.pptx
31/41
,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
7/25/2019 Biomechanics of Spine.pptx
32/41
L t l Fl i &
7/25/2019 Biomechanics of Spine.pptx
33/41
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
7/25/2019 Biomechanics of Spine.pptx
34/41
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
7/25/2019 Biomechanics of Spine.pptx
35/41
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
7/25/2019 Biomechanics of Spine.pptx
36/41
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
7/25/2019 Biomechanics of Spine.pptx
37/41
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
7/25/2019 Biomechanics of Spine.pptx
38/41
Posterior spect
#rimary cervical e,tensors" splenius capitis
splenius cervicis
T%oracic and Lumbar Muscle groups" erector spinae
Semispinalis
deep spinal muscles
7/25/2019 Biomechanics of Spine.pptx
39/41
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
7/25/2019 Biomechanics of Spine.pptx
40/41
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
7/25/2019 Biomechanics of Spine.pptx
41/41