L-spine Flashcards
What is the most important characteristic of the lumbar spine?
Must bear tremendous loads created by body weight
In addition to bearing loads the lumbar spice is largely responsible for?
Trunk mobility
Inferior articular processes are ____and face______in the lumbar spine?
Convex and face anterolaterally
Superior articular processes are ______ and face________?
Concave, Posteromedially
What plane do lumbar faces lie in?
Sagittal
What rules motion?
Facets
Facet configuration limits What? And allows for greater mobility in what?
Rotational flexibility, flexion and extension
L1-l4 facets lie in what plane?
Sagittal
L1-L4 facets limit what?
Axial rotation (0Y)
L5=S1 facets lie in what plane ?
Coronal
L5-S1 facets limit what?
Post/ant shear (z translation)
Lumbar facets normally carry what perfect of axial load?
18 (33 in extension)
What is the primary movement in the lumbar spine?
Flexion/extension
What percent of TRUNK flex/ext occur in the lumbar spine?
75
What is limited by sagittal facet orientation in the lumbar spine?
Axial rotation (0Y)
Is there fore flexion or extension allowed in the lumbar spine?
Twice as much flexion
In the lumbar spine what way does the spinous process move during lateral bending coupled with axial rotation ?
Same side, (except it may switch at L4-L5)
In the lumbar spine where is the nucleus localized in the disc?
Posteriorly
Disc heigh to vertebral body height ratio in the lumbar spine is what?
1:3
The 1:3 ratio of disc to body height in the lumbar spine gives the disc what?
Greater resistance to axial compressive forces
Where does the spinal cord end?
L2
The lumbar spinal canal constrains and protects the lumbar enlargement of the spinal cord proximally _________and the_________distally
Conus medulairs, cauda equina
In the lumbar spine nerve rooks exit the dura where?
Above the foraminal opening
What ligaments define ROM and stabilize the dural sac
Hoffmann ligaments
How does the spinal cord demonstrate flexibility?
Elastic deformation
What is the average range for lumbar lordosis ?
20-60
Where is the apex of the lumbar lordotic curve?
L3-4
The lorditic curve starts to develop when?
9-12 months
The lumnbar lordotic curve becomes established when/
Learn to stand (18 months)
The sacral base angle will_____with an anterior pelvic tilt, relating in ______lubmar lordosis which places more weight bering responsibilities on the facets/
Increase, increase
The sacral base angle will____with a posterior pelvic tilt, resulting on _____lumbar lordosis places more weight bearing responsibility on the_____?
Decrease, decrease, disc
With a posterior pelvic tilt the spines ability to absorbed what kind of force is decreased?
Axial compression forces
What muscle is the major stabilizer of the L-spine?
Quadratus lumborum
What muscle is always active in the L-spine?
Quadratus lumborum
During what movement is the QL least active?
Standing isometric twists
During what is the QL most active?
Heavy lifts
The ALL and PLL restrict what movement in the lumbar spine?
Excessive flexion/extension
What is more developed in the lumbar spine? The ALL or PLL?
ALL
What ligament is highly elastic and acts as a barrier to material that would encroach on the cord during ROM?
Ligamentum flavum
The lumbodorsal fascia is attached to what?
Transverse abdominis, internal oblique and, LATS
What ligament acts like a collateral ligament, controls vertebral rotation ?
Interspinous
What ligament protects against posterior shear?
Interspinous
What ligament provides resistance against excessive forward flexion?
Supraspinous
What respects joint flexion, and restricts distraction of face surfaces during axial rotation?
Facet capsule
What is the most likely cause of ligament damage?
Trauma
What is the result of trauma to a ligament ?
Joint laxity, then degeneration
