sacrum

Question 1

weight of upper body transmitted through sacrum and which ligaments?

Answer 1

• iliolumbar
• sacrospinous
• sacrotuberous

Question 2

which ligaments connect sacrum to pelvis?

Answer 2

• ant and post SI ligaments

- extremely strong

Question 3

what is the 1st ligament to spasm when there is a sacrum dysfx?

Answer 3

iliolumbar ligament

Question 4

mm of the sacrum

Answer 4

• piriformis
• iliacus
• pelvic diaphragm (coccygeous)
• aponeurosis of erector spinae and lat
• gluteus maximus

Question 5

piriformis attachments

Answer 5

• origin: S2-4

- insert: greater trochanter

Question 6

piriformis action

Answer 6

• external rotation of thigh

- abductor of the hip when the hip is flexed

Question 7

piriformis innervation

Answer 7

S1-2

Question 8

piriformis impt

Answer 8

sacral dysfx can lead to piriformis syndrome

Question 9

lumbosacral angle (Ferfuson’s angle)

Answer 9

• 25-35 degrees

- angle increase due to increase lumbosacral strain

Question 10

7 axes of motion of sacrum

Answer 10

• 1 vertical: L/R rotation
• 1 ant/post: sidebending
• 3 transverse: flexion and extension
• 2 oblique: combines all of the above motions

Question 11

superior transverse/ resp axis

Answer 11

• S2

- flexion and ext occurs with resp (flex-exhale; extend-inhale)

Question 12

middle transverse/ postural/SI axis

Answer 12

• S2
• at ant convexity of upper and lower limbs of SI joint
• flex and ext occurs with motion of the sacrum on the ilium

Question 13

inferior transverse/iliosacral axes

Answer 13

• S3
• at post-inf part of the inf limb of SI joint
• flex and ext occurs with motion of ilium on sacrum

Question 14

oblique sacral axes

Answer 14

• named for superior aspect and goes to contralat

Question 15

dynamic sacral motion - gait cycle: walking

Answer 15

sacrum alt: R-on-R, neutral, L-on-L, neutral

Question 16

dynamic sacral motion - gait cycle: stance phase

Answer 16

• ipsilat oblique axis is created, and the sacrum moves ant (obliquely) about this axis
• lumbar spine sidebends ipsilat to the weighted foot because of quadratus lumborum contraction

Question 17

L stance: what sacral motion occurs?

Answer 17

• R-on-R sacral torsion

- lumbar sidebending R

Question 18

SI joint dysfx

Answer 18

• inhibit glut max and medius
• QL inhibit
• disrupt fascial connection from foot into TL region

Question 19

inhibited glut max and medius cause?

Answer 19

• shortens stride
• hamstrings recruited and overused to help extend the hip and leg
• erector spinae recruited and overused

Question 20

spasm of QL cause?

Answer 20

• LBP

- can be activated by standing on the same leg constantly or by jumping and landing on the same leg multiple times

Question 21

disruption of fascial connection from foot into TL region

Answer 21

gait abnormalities

Question 22

L5 rule

Answer 22

• sacrum and L5 rotate opposite each other

Question 23

forward sacral torsion occurs with what lumbar SD?

Answer 23

• neutral mech (type 1)

Question 24

backward sacral torsion occur with what lumbar SD?

Answer 24

• non-neutral mech (type 2)

Question 25

L-on-L sacral torsion

what lumbar SD?

Answer 25

L5 NRRSL

Question 26

tests to dx sacrum

Answer 26

• seated flexion
• sphinx
• landmarks: deep sacral sulcus and ILA
• motion testing

Question 27

b/l sacral shear

Answer 27

• neg seated flexion test
• exaggeration of normal flex or ext
• sacral sulci equal but excessively deep or shallow
• ILA equal but excessively deep or shallow