Spinal Biomechanics: Lumbar

Question 1

Lumbar Biomechanics (L1-L5)
Articular facets primarily move in \_\_\_\_ plane but become more in \_\_\_\_ plane at lumbosacral junction.

Answer 1

sagittal; coronal

Question 2

Lumbar Biomechanics (L1-L5)
Greatest mobility is in ______
_____ limits rotational flexibility

Answer 2

flexion-extension

facet orientation

Question 3

Lumbar Curve
_____ curve of ___*
Begins at ____ and extends to ____. Apex is at ____
Curve is a ____ary in development

Answer 3

Lordotic curve of 20-60* (avg 35*)
Begins at L1-L2 and extends to sacrum
L3-L4
Secondary

Question 4

Lumbar Disc
Disc height to body ratio is ____, allows ROM
Nucleus pulposis located _____teriorly within annulus
Resists ____ compression forces

Answer 4

1:3
posteriorly
axial

Question 5

Lumbar Disc - Force Transmission
Compression force increases pressure in _____. Increases tension in _____. Inhibits radial expansion of _____. Increased pressure against _____. Pressure reinforces _____ creating stable weight bearing

Answer 5

Nucleus pulposis
annular fibrosus
nucleus
vertebral endplates
annulus

Question 6

Disc Bulge
Shallow generalized extension of disc tissues < ____ mm beyond edges of vertebral body.
______ buckle outward
Is it a herniation?

Answer 6

< 3mm
Annular fibers
No

Question 7

Disc Herniation, Focal, Broad-based, or General?
A. Involves <50% of the disc circumference
D. Involves between 25 and 50% of the disc circumf.

Answer 7

A. Focal
B. All
C. General
D. Broad-based

Question 8

Disc Herniation

Shape can be _____ or _____

Answer 8

Protrusion (base is wider than depth)

Extrusion (narrow base, buds off)

Question 9

Annular Tears
Fissures in annulus can be _____, _____, or _____.
_____ may migrate through tears
May ______ disc and cause _____

Answer 9

Radial, transverse, or concentric
Disc material
Weaken, pain

Question 10

Lumbar Flexion-Extension
Combined flex-ext averages ____*
Combines _____ with ______ in _______ plane

Answer 10

15*

rotation, translation, sagittal

Question 11

Lumbar Lateral Flexion
Averages approx. ____* to each side
Lateral flexion coupled with _____ on _____ side

Answer 11

6*

rotation, opposite side

Question 12

Lumbar Lateral Flexion
Body rotation to the _______ and spinous deviation to the _______. This is _____ the coupled motion in the C and upper T spine.

Answer 12

Convexity
Concavity
Opposite

Question 13

Lumbar Rotation
Axial rotation is limited by _____. Avg ____* to each side
Coupled with _____ and slight _____ in _____ plane

Answer 13

Axial facets; 2* to each side

Lateral flexion; sagittal plane rotation

Question 14

Lumbar Rotation
Rotation of _____ is coupled with opposite side lal flex.
Rotation of _____ is coupled with same side lat flex.

Answer 14

L1-L3

L4-L5

Question 15

Lumbar Range of Motion
Greatest flexion-extension is in _____
Greatest lateral flexion is in _____
Greatest Rotation is in _____

Answer 15

L5-S1
L3-L4
Very little in all (2* or less)