L1-2 Lumbar Spine: Biomechanics Flashcards
ROM: lumbar flexion
70-90
ROM: lumbar extension
30-50
ROM: lumbar SB
25-35
ROM: lumbar rotation
20-40
lumbar facet open pack position
flexion
contralateral SB
ipsilateral rotation
lumbar facet closed pack position
extension
ipsilateral SB
contralateral rotation
capsular pattern of lumbar spine facet
normal flexion
decreased extension with rotation
side bending limited equally BL
flexion: arthrokinematics of facet
inferior facet of the upper vertebrae will glide up/forward
flexion: arthrokinematics of disc
nucleus pulposus moves posterior, annulus fibrosis moves anterior
flexion: arthrokinematics of spinal canal
lengthen and open foramen
extension: arthrokinematics of facet
inferior facet of superior vertebrae moves down and back
extension: arthrokinematics of disc
nucleus pulposus moves anterior
annulus fibrosis moves posterior
extension: arthrokinematics of spinal canal
shortens and closes foramen
side bend: arthrokinematics of facets
right SB
right facet glides down, L glides up
side bend: arthrokinematics of intervertebral foramen
R SB
R side closes, L side opens
coupled motion: how/why does it occur
orientation of bones in joints create one motion along with another when one is generated
lumbar coupled motion
SB coupled to contralateral rotation
ex) SB right coupled with left rotation
annulus fibrosis fibers
oriented at 65 degrees, alternating directions with 10-12 layers
resist rotation and torsion
vascular supply of lumbar disc
none!
how does disc get nutrients
osmosis, compression/decompression cycle pumps nutrients in
cause of bulging disc
uneven loading pushing nucleus posteriorly
makeup of intervertebral disc
80% water to 65% water as we age
type 2 collagen
nucleus pulposus and annulus fibrosis allow flexibility at low loads and stability at high loads
which area of lumbar segments get the most sagittal plane motion?
lower
which area of lumbar segments get the most frontal plane motion?
mid lumbar
fryette’s law 1:
neutral spine: rotation in opposite direction of side bend in coupled motion
fryette’s law 2:
full flex/ext, locking facets: rotation and side bending occur in the same direction
fryette’s law 3:
if motion is introduced in one plane, motion in other planes is reduced
eg a spinal segment sidebending will have less rotation than neutral spine
which area of lumbar segments get the most transverse plane motion/rotation?
lumbosacral junction
arthrokinematics of vertebrae in flexion
anterior roll/glide
posterior pelvic tilt
arthrokinematics of vertebrae in extension
posterior roll/glide
comes with anterior pelvic tilt
flexion pattern
common pattern with central back pain
pain worsens with flexion and rotation
reduced lordosis
extension pattern
central back pain
worse with extension and rotation
pain with standing/swimming
often hinge at unstable segment
shows increased lordosis
lateral shift pattern
patient shows recurrent shift with unilateral back pain
shows lateral movement with sagittal plane flex/ext
can have excess QL/erector spinae/multifidi activation
multidirectional pattern
high pain and disability
all movement in WB painful
often unable to achieve neutral spine
flexion syndrome: sahrmann
has more flexion in spine than hip
shortened posterior chain
extension syndrome: sahrmann
more extension in spine than hip
often older pts
pain with lordosis
shortened hip flexors, obliques
rotation syndrome: sahrmann
unilateral pain increasing with rotation only
one segment rotates more easily than ones above or below it
spinal instability
caused by repetitive movement/leg length
flexion with rotation syndrome: sahrmann
unilateral pain increased by flexion with rotation
extension with rotation syndrome: sahrmann
unilateral pain increased by extension with rotation
How to assess disc with McKenzie
repeated motion or sustained positions
closing restriction
facet limitation in ext, ipsl SB, CL rotation
opening restriction
facet limited in flexion, CL SB, ipsl rotation
compression forces do what to lumbar spine
compress disc
cause disc to bulge/widen
tension force does what to lumbar spine
pulls apart loading structures
can cause injury in trauma like hyperextension
shear force does what to lumbar spine
load parallel to vertabrae
caused by trauma or repetitive force
spondylolisthesis causing anterior shift with flexion
torsional force effect on lumbar spine
twisting stresses and injures soft tissue
caused by generation of large muscle forces
loads IV disc
slump test
tesnions nerves
pt in seated, slump forward
straighten leg then DF
worse in slump - internal problem
worse sititng up - external problem of nerve, adhesion
disc pressure by position - least to most disc pressure
supine
sidelying
standing
seated
lean forward
seated lean forward
lean forward standing with weight
seated lean forward with weight
symptoms based classification
symptom modulation - active rest, control pain
movement control - address impairments, irritated structures w/ ther ex
functional optimization - symptoms resolved, return to high level activity
painful arc in flexion
pt often has pain in midrange but not early or end range
painful arc
pain only on return from lumbar flexion
also often in midrange
gower’s sign
thigh climbing where pt needs to push on thighs for assistance when returning to uprught from flexion
instability catch
any trunk movement outside of the specified motion with sudden accleration/deceleration
eg going into flexion and sudden SB
reversal of lumbopelvic rhythm
when returning from flexion to neutral, trunk extending first, then hips and pelvis extend to bring body upright
