LECTURE 2A: LUMBAR SPINE Flashcards
horizontal articular surfaces favor ___ rotation
vertical surfaces BLOCK____ rotation
horizontal: AXIAL
vertical: BLOCK AXIAL
Is the IVD thicker anteriorly or posteriorly in lumbar/cervical spine?
ANTERIOR (lordosis)
*largest avascular structure in body
what 2 major stresses in the IVD cause disc herniations?
bending, twisting
(also resist shear, axial compression, combined motions)
___ stability is the state of equilibrium when body is still
mechanical (static)
___stability is made of 3 systems
1. passive (end range resistance)
2. active (mm)
3. CNS (feedforward/feedback to augment stiffness)
CONTROLLED/DYNAMIC
If your passive structures are damaged, what works really hard?
active structures (fatigue faster)
open pack lumbar spine position
midway between flexion and extension
closed pack position of the lumbar spine
full extension
capsular pattern of lumbar spine
SB/rotation
extension
In L5,
disc surface is ___
TP is ___
SP is ______
disc: smaller
TP: larger
SP: smaller
(vertebral body is wedge shaped)
If S1 becomes too mobile, this is called
lumbarization
If L5 fuses to sacrum, this is called
sacralization
zygapophyseal joint capsule is TIGHT IS ____ positons
ALL positions
If isthmus breaks =
spondylolysisI
If L5 displaced anteriorly, =
SPONDYLOLISTHESIS
WHICH ligament resists extension or excessive lordosis
ALL
*if injured not painful
Which ligament resists flexion and traction?
PLL
which ligament resists flexion, slacks only with extension?
*strongest in lumbar
ligament flavum
interspinous and supraspinous ligament resists what?
hyperflexion!
supraspinous doesnt attach directly to L4/5
which ligament limits contralateral side bending
intertransverse ligament
annulus fibrosis transmits what forces?
compression, shear, torsion
nucleus pulposes ABSORBS
compression and shear
what part of disc degenerates first?
end plate
ROTATOR cuff of facet joint producing compression force during contraction
multidfidi