Lumbar biomechanics

Question 1

what is the shape of the lumbar pedicles and laminae?

Answer 1

short broad and strong

Question 2

What is the shape of the spinous processes of lumbar vertebrae?

Answer 2

thick and broad

Question 3

what is the shape of the lumbar transverse processes?

Answer 3

long slender and flattened on the anterior and posterior survaces.

Question 4

what is the feature on the superior articular processes?

Answer 4

mamillary process, I think its used as landmark in manipulation.

Question 5

What direction are the lumbar fascets facing?

Answer 5

they are in the saggital plane mostly so they face medailly and laterally.

Question 6

degrees of the lumbar fascets?

Answer 6

45 degrees from the frontal plane and 90degrees from transverse

Question 7

What is the degree of the lordodic curve?

Answer 7

20-60 degrees with and average of 35. from L1 to sacrum

Question 8

Where is the apex of the lordodic curve?

Answer 8

L3-L4 is the apex

Question 9

what causes lordodic secondary curve to form?

Answer 9

it happens in response to standing.

Question 10

what tilt increases or decreases lordosis?

Answer 10

Antior pelvic tilt decreases, posterior pelvic tilt increases lordosis.

Question 11

Where is the nucleus pulposis located in lumbar disk?

Answer 11

it is posterior in the disk, similar to cervical, while thoracic is centered

Question 12

what does huge lumbar disk help resist?

Answer 12

axial compression forces

Question 13

what inhibits ratial expansion of nucleus pulposus?

Answer 13

the increased tension of the annular fibrosis.

Question 14

if annulus doesn’t expand with increased hydrostateic pressure what does it do?

Answer 14

increase pressure up and down twoard the end plates.

Question 15

what is a disk bulge?

Answer 15

shallow generalized extension of the disc tissues beyond the edges of the vertebral gody

Question 16

is a disc bulge a herniation?

Answer 16

No

Question 17

what may a disc bulge cause?

Answer 17

compression of neural tissues, pain and joint disfunction

Question 18

In what directions can disk bulge?

Answer 18

Symmetrically, asymetrically twort one side,

Question 19

Is shape of disc in bulge diagnostic?

Answer 19

no

Question 20

where is assymetrical bulging of the disk margin often found?

Answer 20

in severe scoliosis

Question 21

what is a herniation?

Answer 21

When disk fibers rupture through the annular fibers.

Question 22

What can disc herniation cause?

Answer 22

compress Nerve, pain, inflammation,

Question 23

what is concidered a localized herniation?

Answer 23

involves less than 50% of the disc circumference.

Question 24

What is a focal herniation?

Answer 24

involves less than 25% of the disc circumference

Question 25

What is a broad base herniation?

Answer 25

involves between 25 and 50% of disc circumference.

Question 26

what are the two forms of herniated disc?

Answer 26

protrusion or extrusion

Question 27

What is a protrusion shaped herniation?

Answer 27

base of herniation is broader than the distance is protrudes into spinal canal. So broad

Question 28

What is a extrusion shaped herniation?

Answer 28

disc balloons into canal with a narrow base, may end up sequestered.

Question 29

what directions can annular tears form?

Answer 29

radial - transvers or concentric

Question 30

what can annular tears do to disc?

Answer 30

weaken, pain in outer 1/3 and disk material may get into tears.

Question 31

what is the compined lumbar segment flexion and extension?

Answer 31

15 degrees

Question 32

what are the combined movements of lumbar flex/extend?

Answer 32

saggital plane rotation and translation.

Question 33

in flexion of lumbar what happens to vertebrae and fascets.

Answer 33

vertebra, foreward tilt and slide, facets- slide up

Question 34

in extension of lumbar what happens to vertebrae and facets?

Answer 34

vertebra - tilt back, Fascet- approximate - squish together

Question 35

what is the averge lumbar lateral flexion?

Answer 35

6 degrees to each side although the lumbar sacral only has 3 degrees

Question 36

what happens to lumbar facets in lateral flex?

Answer 36

in right lat flex, right facets glide close, left facets glide apart.

Question 37

what is the coupled rotation of lumbar lateral flexion?

Answer 37

lat flexion with opposite side rotation, so flex left will rotate right, opposice of cervical and upper thorsic

Question 38

why is lumbar roatation so limited?

Answer 38

the saggital fascets limit it to 2 degrees each side.

Question 39

what is the coupled rotation of lumbar rotation?

Answer 39

rotation with lateral flesion and slight saggitaal plane rotation.

Question 40

specifically what is the difference between upper and lower lumbar rotation?

Answer 40

Upper lumbar rotation has opposite side lateral flesion, lower lumbar rotation L4-L5 is coupled with same side lateral flexion.