Lumbar Spine AEP Flashcards
lumbar lordosis
- where is it
- decreased lumbar lordosis associated with…
- lumbar lordosis inversely proportion to…
- decreased _____ effort when lordosis maintained
66% of lumbar lordosis from L4-S1
decreased lumbar lordosis associated with L5S1 disc degeneration
intradiscal pressure inversely proportional to lumbar lordosis
decreased extensor effort when lordosis maintained
measurement of lumbar lodrosis
- gold standard
- external measurement methods
- all external measures vs. radiograph
gold standard -radiographic measurement -range from 47-64 degrees external measures -bendable rulers -strain gauges embedded in tape -inclinometers -accelerometers all have poor concurrent validity
radiographic measurement - total lumbar lordosis
-how is it measured
line parallel to superior endplate of L1
line parallel to inferior endplate of L5
perpendiculars drawn to these lines
angle bewteen the intersection is measured
functional spinal unit
-composition
two adjacent vertebral bodies
intervertebral disc (IVD)
associated soft tissue
“motion segment”
lumbar vertebral structure
- anterior elements
- posterior elements
anterior -two vertebral bodies -IVD -longitudinal ligaments posterior -vertebral arches -spinous and transverse processes -facet joints -posterior ligaments
anterior elements function and characteristic
bear compressive loads larger caudally (loading increases)
posterior elements
- function
- motion determined by…
guide movement
motion determined by facet joint orientation
facet joint function
restrict motion
muscle attachments
transverse processes
-functions
muscle and ligament attachments
increase moment arm
spinous processes functions
muscle and ligament attachments
increase moment arm
facet joints
- level of innervation
- what type of innervation
highly innervated types -mechanoreceptors --> proprioception -nociceptors --> pain disruption of the mechanoreceptors may lead to LBP
lumbar facet joints
- joint surface orientation
- orientation allows…
orientation -90 to transverse plane -45 to frontal plane allows -flexion/extension -lateral flexion -minimal rotation
lumbosacral joint
- orientation
- allows…
oblique orientation
-allows rotation
lumbar facet joints - load sharing
- with what?
- dependent on…
shares load with IVD
posture dependent
lumbar facet joints and hyperextension
30% of total load on facets
lumbar facet joints and flexion coupled with rotation
increases loading of facets
anterior longitudinal ligament
- attachment
- tight in_____
vertebral body attachment (less to disc)
tight in extension
PLL
- attachment
- tight in_____
IVD attachment (less to body) tight in flexion
ligamentum flavum
- function
- difference compared to other ligaments
- -why is this important
- function
connects adjacent vertebral arches high elastin content -makes it more of an active ligament -contracts during extension -elongates during flexion under constant tension -pre-stresses the disc to create intradiscal pressure -provides stability to the spine
IVD
- components
- functions
components -inferior/superior endplates (bony) -annulus fibrosis -nucleus pulposus functions -weight bearing -load distribution -restrains excessive motion
IVD - nucleus pulposus
- what is it
- components
- what happens with age
gelatinous mass
hydrophilic glycosaminoglycan (GAG) content
GAG and water content decrease with age
IVD - annulus fibrosis
- what is it
- layers with…
fibrocartilage
layers with different collagen fiber orientations
intradiscal pressure (IDP)
- what is it
- nucleus pulposus is…
- role of posture (classic study)
hydrostatic pressure within the disc ensures uniform load distributino nucleus pulposus in incompressible - resists compressive loads posture (low to high pressure) -lying -standing -sitting -forward bending (leaning over) -forward bending with sitting
IDP
-newer study findings
IDP lower in unsupported, relaxed sitting than in standing
found IDP increased over 7 hours of rest (sleeping)
kinematics of the lumbar spine
-DF
flexion/extension lateral flexion rotation A/P translation M/L translation superior/inferior translation
osteokinematics
- primary motion and amount
- secondary motion and amount
- tertiary motion and amount
primary -sagittal plane -12-20 at each segment secondary -frontal plane -6 at each segment tertiary motion -transverse plane -2 at each segment
lumbosacral joint
- where is this?
- orientation
- allows…
- limits…
L5S1
oblique orientation
-allows rotation and flexion
-limits lateral flexion
arthrokinematics - facet joints
- approximation (closing)
- separation (gapping)
- sliding (gliding)
approximation -facet surfaces move closer together separation -facet surfaces move further apart sliding -linear translation of facet surfaces in the plane of the facet joint
arthrokinematics
-flexion
inferior facets of superior vertebra slide upward on superior facets of inferior vertebra
arthrokinematics
-extension
inferior facets of superior vertebra slide downward on superior facets of inferior vertebra
arthrokinematics
-lateral flexion
ipsipateral downslide
contralateral upslide
arthrokinematics
-R rotation
separation of right facet joint
approximation of left facet joint
arthrokinematics
-L rotation
separation on left facet joint
approximation of right facet joint
coupled motion - lumbar spine
-what PTs should know
should use caution when applying coupled motion concepts to lumbar spine
-studies do not agree on what direction it occurred
why do we care about coupled motion (in general)?
assessment of active motion -observe compensatory motions assessment of passive motion/mobility -assess coupling patterns clinical intervention -guide direction of mobilization, treat restrictions in both motions to restore the primary movement
