SIJ, sacrum, pelvis - exam 1

Question 1

what are the regions where SIJ pain can occur?

Answer 1

ipsilateral lower lumbar region
medial buttock
PSIS
short and long SIJ ligament

Question 2

thoracolumbar fascia plays an important role in what?

Answer 2

mechanical stability of the low back and SIJ

Question 3

true or false. the thoracolumbar fascia is most extensive in the lower back and attaches at the PSIS

Answer 3

true

Question 4

describe the shape of the sacral joint

Answer 4

ear or L shaped
vertical = short arm
horizontal = long arm

Question 5

what type of cartilage is on the sacral joint surface?

Answer 5

hyaline/articular cartilage 1-3 mm
white and smooth

Question 6

what type of cartilage is on the iliac side of the SI jt?

Answer 6

fibrocartilage 1-2 mm thickness

Question 7

describe the characteristics of the sacral joint surface

Answer 7

• irregular ridges and depressions that are matched by reciprocal shapes on the ilium
• interlocking contours prevent downward gliding of sacrum
• twists

Question 8

what is innominate motion?

Answer 8

iliac crests move on sacrum

Question 9

what is sacroiliac motion?

Answer 9

sacrum moves on innominates

Question 10

can the sacrum and iliac crests move separate of one another? give example

Answer 10

yes
kicking a ball –> one leg stays one leg goes forward

Question 11

movement at the SIJ occurs in how many planes of motion?

Answer 11

3

Question 12

what is nutation?

Answer 12

anterior/forward motion
flexion of sacrum

Question 13

what is counternutation?

Answer 13

posterior/backward motion
extension of sacrum

Question 14

describe the arthokinematics of nutation of the sacrum

Answer 14

• sacrum moves forward –> anterior/inferior
• innominates glide inferior down short arm and posterior along long arm
• motion is resisted by wedge shape of sacrum, ridges/depression, interosseous and sacrotuberous ligaments

Question 15

describe the arthrokinematics of counternutation of the sacrum

Answer 15

-sacrum moves superior/posterior
- innominates glide anterior along long arm and superior up short arm
- motion resisted by long dorsal ligament

Question 16

compare the movements of the pelvis and sacrum

Answer 16

sacrum and pelvis move relatively of one another
–> sacrum moves forward and pelvis appears to move backwards but relatively

Question 17

what is supposed to physiologically happen on the oblique axis’ when the sacrum moves?

Answer 17

turned left on left axis
turned right on right axis

Question 18

when is the sacrum in a closed pack position? is it stable?

Answer 18

closed pack is full nutation –> standing so loaded
stable –> gravity, ligaments, and muscles create stability

Question 19

what position is someone in when the sacrum is less stable? is that nutation or counternutation?

Answer 19

supine –> unloaded
sacrum tends to return to counternutation so less stable