III. Biomechanics of the Lumbar Spine Flashcards
What are common sources for low back pain?
disc facet joints soft tissue
What are the major functions of the lumbar spine?
support for trunk and upper extremities resist compression provide mobility muscular attachment protect the spinal cord/cauda equina
How does the width of the lumbar vertebrae change from above down?
width increases
what kind of curve does the lumbar spine form?
lordotic
What is the normal lumbar lordosis angle?

40-60 degrees
What is the normal lumbosacral angle?

26-57 degrees
What is the shape of a lumbar vertebral body?
kidney
Are lumbar vertebral bodies wider side to side or A to P?
side to side
What is the approximate height of an IVD in the lumbar region?
9mm
What percentage of spinal height is attributed to IVD height?
25%
What is the ration of IVD to vertebral body height in cervical region?
2 : 5
What is the ration of IVD to vertebral body height in thoracic region?
1:5
What is the ration of IVD to vertebral body height in lumbar region?
1:3
The large disc to vertebral body height ratio seen in the lumbar region attributes to what?
increased lumbar flexibility
increased shock absorption
Nucleus puplosus is located where in the disc?
posterior 1/3

What causes the nucleus pulposus to become mobile?
annular tearing
How much possible height variation may occur in a person throughout the day due to IVD hydration/dehydration?
3/4”
How much possible height loss may occur in a person due to normal IVD aging?
1 inch
What plane are the articular fects of the lumbar spine in?
mostly sagittal but becoming more coronal at L5
Which articular facet surface in the lumbar region is convex, superior or inferior?
inferior
Which articular facet surface in the lumbar region is concave, superior or inferior?
superior
Which articular facets face inferiorly, laterally and anteriorly in the lumbar region, superior or inferior?
inferior
Which articular facets face superiorly, medially and posteriorly in the lumbar region, superior or inferior?
superior
Where is the most common site for facet asymmetry (facetal tropism)?
lumbar region





