lumbar Spine Flashcards
Lumbar vertebrae 1-4
Facets in SAGITTAL plane
More FLEX/EXT
Less Rotation
L5-S1
More in Frontal plane
Prevents anterior translation of L5 on S1
Allows more Rotation
The more the facet joint is oriented in the frontal plane, the more it resists…
SAGITTAL plane motion, but less control of transverse plane
Nucleus pulposus
70-90% water, good for shock absorption, avascular, no innervation
Annulus fibrosis
Neural innervation.
Resists compression
Less shearing
What absorbs force from nucleus pulposus
End plates
Effects to intervertebral discs with Age
Decreased H2O in nucleus pulposus
Increased collagen content
Increased stress on annulus fibrosis (thinnest posteriorly)
With Flexion of intervertebral disc
Anterior AF compressed, NP compressed into the AF causing stretch
Intervertebral is more vulnerable to injury with which movements?
Flexion and Rotation
How does the pelvis and hips increase lumbar mobility?
Through pelvic tilting
8-13 degrees of flexion are limited by
Posterior ligaments and Disk facets joint
1-5 degrees of extension are limited by
Bony contact
1-2 degrees of rotation are limited by
Facet joints and AF tension
Limbo-pelvic movement
Anterior tilt and flex occurs in both simultaneously
Lumbo pelvic Ext
Posterior pelvic tilt leads to lumbar extension until pelvis neutral then further lumbar ext to neutral