Lumbar Spine Part 2 Flashcards
decreased lordosis
- lumbar spine arthrokinematics
- why is this important
bilateral upslide
- decreased contact area
- -more force/area (while there is decreased pressure overall at the facet joint, there is decreased contact area so there is more force/area)
decreased lordosis
- loading differences on spine
- what structures are affected
more compression
-pressure movign from facets to anterior IVD and vertebral bodies
increased lordosis
-lumbar spine arthrokinematics
downslide
increased lordosis: position of
- lumbar spine
- pelvis
- hip
- knee
spine -extension pelvis -anterior tilt hip -flexion knee -flexion or extension
increased lordosis
- loading
- affected structures
increased shear (particularly at L5S1) increased pressure on posterior IVD compression of interspinous ligaments reduced diameter of intervertebral foramina -nerve entrapment
importance of lumbar facet downslide with increased lordosis
increase force
will be almost locked out in resting posture
effect of prolonged flexion (seated or standing) on dysfunction
adaptive shortening of muscles and connective tissues
increased flexor moment on the spine
increased pressure on anterior aspect of IVD
-may weaken posterior annulus fibrosis over time
impact on the entire kinetic/kinematic chain
effect of prolonged hyperextension on dysfunction
compression of facets
increased anterior shear at lumbosacral junction
may lead to development of spondylolisthesis
-anterior ligaments are compromised
effect on kinetic/kinematic chain
posterior muscles of the trunk: intermediate later
- what
- function
serratus posterior
little contribution to movement or stability
primarily contribute to ventilation
erector spinae
-function
control gross movement across a large part of axial skeleton
generate large extensor moment for lifting/carrying (bilateral)
erector spinae group
-can _____ tilt pelvis and _____ lordosis
can anteriorly tilt pelvis and increase lordosis
multifidi function
extension torque and stability
-multiple attachments and overlapping fibers
transversospinalis functions
bilateral extension
unilateral contralateral rotation, ipsilateral lateral flexion
short segmental group
- most prominent in…
- blend with…..
- most important role
most prominent in craniocervical region for control of neck
blend with interspinous ligaments
-intervertebral stabilizers
most important role
-sensory feedback (high density of muscle spindles)
anterior rectus sheath
-comes from
internal and external obliques
posterior rectus sheath
-comes from
interal oblique and transversus abdominus
sheaths thicken and cross at midline to form…
linea alba
rectus abdominus
-actions
trunk flexion
posteirior rotation of pelvis
internal, external oblique, and transversus abdominus
-function
“hoop” muscles - important stabilizers
external oblique actions
bilateral
-trunk flexion, posterior pelvic tilt
unilateral
-lateral flexion, contralateral rotation
internal oblique actions
bilateral -trunk flexion, posterior pelvic tilt -tensions thoracolumbar fascia unilateral -lateral flexion -ipsilateral rotation
transversus abdominus
-function
stabilizes attachment sites for other muscles
compresses abdominal cavity
tension thoracolumbar fascia
“additional” muscles of the trunk
psoas major
quadratus lumborum
psoas major function
vertically stabilizes the lumbar spine
-line of action close to rotation axes
strong hip flexor
QL functions
bilateral
-extension
unilateral
-lateral flexion (open chain - elevates pelvis)
sagittal plane muscles (erector, rectus)
- orientation
- motions
primarily flexion/extension (bilateral)
lateral flexion depends on moment arm from midline
frontal plane movers
- what muscles
- vertical force component gives
- horizontal force component gives
any muscle with oblique orientation vertical force -lateral flexion horizontal force -transverse rotation
transverse plane
-what muscles
multifidus
external oblique
extrinsic stabilizers of the trunk
- what are they
- what do they do
attach to structures outside the vertebral column
global stability
what muscles are extrinsic?
abs erector spinae hip muscle QL psoas lat scapular muscles
intrinsic stabilizers
- what are they
- what do they do
segmental stability
short, deep muscles that attach to structures within spinal column
what muscles
transversospinalis -semispinalis -multifidi -rotatores short segmental group -interspinalis -intertransversarii
“general” versus “specific” stabilization
better short-term outcomes with “specific (ultrasound feedback) motor control exercises but no differences long term
specific stabilization exercises effective for chronic but not acute LBP
individually designed, higher intensity programs may be most beneficial
TrA
- theory
- selectively activate through…
theory
-a primary specific stabilizer for lumbar spine
–based on findings that TrA function impaired in people with LBP
selectively activate through “drawing in maneuver”
drawing in maneuver
-function
increases intra-abdominal puressure and tension thoracolumbar fascia without moving lumbar spine
how to teach drawing in maneuver
use biofeedback - EMG or pressure
TrA: pressure biofeedback
-diagnostic accuracy
no correlation bewteen pressure biofeedback and TrA activation on ultrasound
no difference in TrA activation between those who were and were not able to perform exercise successfully (no change in pressure)
implications for pressure biofeedback
success with pressure biofeedback has been associated with improved outcomes
-pressure biofeedback is good, but it doesn’t necessarily mean they have learned how to use their TrA
TrA take-home messages
muscles do not work in isolation
-there is more to it than TrA alone
focus on perfect performance of the desired movement/task
-atypical compensations should become apparent
likely using a combination of global and segmental stabilizing muscles
always return to foundation principles, function anatomy, motor control
