Exam 2 Lumbopelvic

Question 1

What is the most important characteristic of the lumbar spine?

Answer 1

it must bear tremendous loads created by body weight, lifting, and muscle actions

Question 2

In addition to bearing heavy loads, what other responsibility does the lumbar spine have that places significant biomechanical demand on this region?

Answer 2

trunk mobility

Question 3

T/F: the inferior articular processes of the L/S are concave and face anterolaterally.

Answer 3

False; convex

Question 4

Describe the superior articular processes of the L/S.

Answer 4

concave and face posteromedially

Question 5

What plane do the lumbar facets lie in primarily?

Answer 5

the sagittal plane

Question 6

What motion is limited in the L/S? increased?

Answer 6

rotation;

flexion/extension

Question 7

Which facets of the L/S have a coronal orientation rather than sagittal? What motion does this limit?

Answer 7

L5/S1 facets;

limits posterior/anterior shear (Z translation)

Question 8

T/F: the lumbar facets normally carry 18% of the axial load and up to 33% in extension.

Answer 8

True

Question 9

Which region of the L/S has the greatest combined flexion/extension? Least?

Answer 9

L5-S1;

L1-L2

Question 10

Which region of the L/S has the greatest range of lateral bending (ThetaZ)? Least?

Answer 10

L3-L4;

L5-S1

Question 11

Which region of the L/S has the greatest one side axial rotation (Theta Y)? Least?

Answer 11

L1-L5 all have relatively equal axial rotation;

L5-S1 has the least axial rotation

Question 12

What motions are coupled in the L/S? What does this mean for spinous?

Answer 12

lateral bending is coupled with axial rotation;

spinous to ipsilateral side

Question 13

Is the nucleus of the IVD in the L/S more anterior, posterior, or in the middle?

Answer 13

posterio

Question 14

What is the disc height-to-body height ratio in the L/S?

Answer 14

1:3; greatest resistance to axial compressive forces

Question 15

What is the name for the enlargement of the spinal cord that is protected by the L/S? What other main structure is protected by the L/S distal to the lumbar enlargement of the spinal cord?

Answer 15

conus medullaris;

cauda equina

Question 16

What bone is the CNS tethered to via the filum terminale?

Answer 16

coccyx

Question 17

Where does the spinal cord end? What do the nerve roots continue down the spinal canal as?

Answer 17

L2:

cauda equina

Question 18

T/F: Nerve roots exit the dura of lumbar spinal canal slightly below the foraminal openings to provide “slack” which prevents stretching of the nerve roots.

Answer 18

False; NRs exit the dura slightly above the foraminal openin, causing therir course to be more oblique and their length to increase

Question 19

T/F: The Lordotic curve of the L/S is considered a primary curve.

Answer 19

False; secondary curve

Question 20

Where is the apex of the Lumbar curve?

Answer 20

L3-4 disk

Question 21

What range (in degrees) should the lumbar curve measure?

Answer 21

20-60 degrees

Question 22

T/F: An increase in the sacral base angle will result in more weight bearing responsibility on the facets.

Answer 22

True; increasing the sacral base angel with an anterior pelvic tilt results in an increase in the lumbar lordosis which places more weight on the facets.

Question 23

T/F: An increase in the sacral base angle will result in more weight bearing responsibility on the disc which will decrease the spine’s ability to absorb the axial compression forces.

Answer 23

False; A decrease in the sacral base angle will do this as it decreases the lumbar lordosis

Question 24

What muscle is the major stabilizer of the L/S?

Answer 24

Quadratus lumborum

Question 25

What motions are restricted in by the ALL and PLL? Which is more well developed?

Answer 25

Restrict excessive flexion/extension; | ALL>PLL

Question 26

T/F: The lumbodorsal fascia acts like a large flexor retinaculum to constrain long tendons of thoracic and lumbar muscles.

Answer 26

False; acts as a large extensor retinaculum constraining thoracic and lumbar extensors

Question 27

What ligament of the L/S guards against posterior shear, assists facet joints to remain in contact/gliding with rotation, and acts like a collateral ligament controlling vertebral rotation to follow an arc through flexion range?

Answer 27

Interspinous ligament

Question 28

What motion does the supraspinous ligament provide resistance against?

Answer 28

excessive forward flexion

Question 29

T/F: The facet capsule is well developed in the L/S, restricting joint flexion and distraction of facet surfaces during axial rotation.

Answer 29

true

Question 30

What are the 3 pelvic joints?

Answer 30

2 SI joints and the pubic symphysis

Question 31

T/F: SI joints are immobile syndesmotic joints.

Answer 31

False; they are mobile diarthrodial joints (though they were once thought to be immobile syndesmotic)

Question 32

What are the main responsibilities of the pelvic joints?

Answer 32

support for the trunk, guide movement, and help to absorb the compressive forces associated with locomotion and weight-bearing

Question 33

What is the keystone effect of the sacrum?

Answer 33

the sacrum is triangular and serves as a keystone in the arch between the two columns formed by the lower extremities effectively distributing axial compressive forces

Question 34

When do the SI joint surfaces begin to roughen and develop their characteristic grooves and ridges?

Answer 34

teen years

Question 35

What are the 2 most common pelvic types?

Answer 35

gynecoid and android

Question 36

What are the 4 main ligaments of the pelvis?

Answer 36

Sacrospinous, anterior sacroiliac, sacrotuberous, and posterior sacroiliac ligaments

Question 37

T/F: Although the SI joint was once thought to be immobile, it is now universally accepted as a movable joint, how it moves, how much it moves, and where axes of motion are located.

Answer 37

False; there is still a lot of controversy about the SI joint

Question 38

T/F: The SI joint is most active while maintaining erect posture.

Answer 38

False; most active during locomotion

Question 39

What direction does an innominate move as it flexes?

Answer 39

posteriorly and inferiorly

Question 40

Which way does the sacral base move during nutation? counternutation?

Answer 40

anteriorly and inferiorly; | posteriorly and superiorly

Question 41

T/F: The proposed axes of motion in the SI articulation allow a "gyroscopic" figure-4 movement.

Answer 41

False; figure-8 movement

Question 42

T/F: Flexion of the SI joint incorporates anterior and superior movement of the PSIS and ipsilateral posterior and superior movement of the sacral base (counternutation).

Answer 42

False; this is true of extension

Question 43

T/F: The Quadratus lumborum, erector spinae, gluteus maximus, gluteus minimus, piriformis, iliacus, and latissimus dorsi muscles all cross the SI joint.

Answer 43

False; no muscle crosses the SI joint, but all of these muscles listed have fibrous expansions that blend with the anterior and posterior SI joint ligaments which contributes to the strength of the joint capsule and ligaments.

Question 44

T/F: the muscles impacting the SI joints help provide mobility.

Answer 44

False; provide stability, not mobility

Question 45

If the left ilium has a PIEX listing, what orthogonal directions has it moved?

Answer 45

-thetaX and -thetaY

Question 46

If the right ilium has an ASIN listing, what orthogonal directions has it moved?

Answer 46

+thetaX and -thetaY

Question 47

If the left ilium has an ASIN listing, what orthogonal directions has it moved?

Answer 47

+thetaX and +thetaY

Question 48

If the sacrum has a base posterior listing, what orthogonal direction has it moved?

Answer 48

-thetaX

Question 49

If the sacrum has an SAL listing, what orthogonal direction has it moved?

Answer 49

+thetaZ

Question 50

If the sacrum has a P-R listing, what orthogonal direction has it moved?

Answer 50

-thetaY