Lumbar Spine

Question 1

what is unique about the structures of hte lumbar spine?

Answer 1

large vertebral foramen and bodies

Question 2

L5 transitional vertebra is larger in which direction?

Answer 2

anteriorly

Question 3

what movements dot he lumbar spine favor and not favor as much?

Answer 3

favors flexion/extension

less lateral flexion and rotation

Question 4

Size of vertebral foramen by extension by what percentage? what can this eventually lead to if excessive extension?

Answer 4

10%, nerve compression

Question 5

coupled motion in flexion

Answer 5

rotation and lateral flexion to the same side

Question 6

which vertebra has the largest amount of flexion and rotation? (where is the curve the largest when flexing forward?)

Answer 6

L2, L3

Question 7

what degree are the collagen fibers oriented at and what direction is it in?

Answer 7

120 degrees, opposite direction

Question 8

Describe IV disc hydration.

Answer 8

throughout the day, compressive loads cause loss of fluid. at night, reloading of fluid occurs.

Question 9

in flexion, which direction does the disc move?

Answer 9

posterior

Question 10

in rotation, what direction is the disc moving?

Answer 10

not rotating, just putting stress on the annulus

Question 11

increase angle –> increase lordosis –> increase _____

Answer 11

shear

Question 12

when do you have greater shear forces?

Answer 12

lumbosacral angle greater than 45 degrees

Normally, we have more compression

Question 13

which muscles cause SOME posterior shear and MOSTLY compression?

Answer 13

deep erector spinae

Question 14

why is the superficial erector spinae group considered a prime mover?

Answer 14

longer lever arm

Question 15

what is causing tension at the throacolumbar fascia?

Answer 15

transversus abdominis, hip extensors applying tension on spinous processes, glut mac & contralateral lats,

Question 16

Name the muscles of the anterior hoop.

Answer 16

rectus & transverse abs, external and internal obliques

Question 17

which muscle controls the sacroiliac joint?

Answer 17

transversus abdominis

Question 18

in lumbar extension, what happens at the pelvis?

Answer 18

posterior pelvic tilt

Question 19

how much compression occurs at the lumbar interbody joints? how much on the facets?

Answer 19

80%, 20%

Question 20

what specific structures limit anterior shear?

Answer 20

facets

Question 21

how do the multifidi muscles act?

Answer 21

acts on individual segments

Question 22

what is the action of quadratus lumborum?

Answer 22

ipsilateral flexion, contralateral eccentric control

Question 23

what does the iliolumbar ligament prevent?

Answer 23

anterior sheer

Question 24

when is the iliolumbar ligament loaded?

Answer 24

in flexion

Question 25

what motion do the iliolumbar ligaments resist?

Answer 25

movment of L5 on S1

Question 26

what occurs to the lumbar spine when bending forward?

Answer 26

tension on the posterior ligaments, anterior shear on the upper vertebral body, compression on the anterior disc

Question 27

how to increase the stability of the lumbar spine. (3)

Answer 27

1. use co-contraction of flexors and extensors 2. increase intra-abdominal pressure 3. have sufficient stability; too much can cause joint compression

Question 28

what has more pressure on IV disk: sitting unsupported or standing?

Answer 28

sitting unsupported

Question 29

Sitting unsupported is the same pressure as ______

Answer 29

coughing

Question 30

lifting 100N causes greater/less force than holding 50N at arms length

Answer 30

less force