Chapter 6 Sacrum and Innominate Anatomy

Question 1

When do the 3 bones of the innominate fuse?

Answer 1

20 years old

Question 2

Anterior portion of 1st segment (S1)?

Answer 2

Sacral promontory

Question 3

Sacral base?

Answer 3

Top (most cephalad) part

Question 4

In somatic dysfunctions, what can be recorded as shallow (posterior) or deep (anterior)?

Answer 4

Sacral base or sacral sulci

Question 5

How can you record the sacral ILA’s?

Answer 5

Shallow (posterior), deep (anterior), superior or inferior

Question 6

The SI joint is an inverted “L” joint with 2 arms converging anteriorly. Where do these arms join?

Answer 6

S2

Question 7

2 types of pelvic ligaments/

Answer 7

True and accessory

Question 8

True pelvic ligaments?

Answer 8

Anterior, posterior and interosseous SI ligaments

Question 9

Accessory pelvic ligaments?

Answer 9

Sacrotuberous, sacrospinous, iliolumbar ligaments

Question 10

What ligament divides the greater and lesser sciatic foramen?

Answer 10

Sacrospinous ligament

Question 11

Which ligament is the 1st to become painful in lumbosacral decompensation?

Answer 11

Iliolumbar ligament

Question 12

Types of pelvic muscles?

Answer 12

Primary and secondary

Question 13

Primary pelvic muscles?

Answer 13

Make up pelvic diaphragm–levator ani, coccygeus

Question 14

Secondary pelvic muscles?

Answer 14

Iliopsoas, obturator internus, piriformis

Question 15

Origin/insertion of piriformis?

Answer 15

ILA, greater trochanter

Question 16

Action of piriformis?

Answer 16

Ext rot, extend thigh, abducts thigh with hip flexed

Question 17

Innervation of piriformis?

Answer 17

S1 and S2 nerve roots

Question 18

What are S/S of sciatica due to hypertonic piriformis?

Answer 18

Pain from buttock radiating down thigh but not past knee

Question 19

Axis upon innominates rotate?

Answer 19

Inferior transverse axis (S4)

Question 20

4 types of sacral motion?

Answer 20

1) Dynamic motion
2) Respiratory motion
3) Inherent (craniosacral) motion
4) Postural motion

Question 21

Location of transverse axis for resp and inherent motion of sacrum?

Answer 21

S2 (superior transverse axis)

Question 22

Craniosacral flexion induces what sacral motion?

Answer 22

Counternutates (rotates posterior)

Question 23

Craniosacral extension induces what sacral motion?

Answer 23

Nutation (rotates anterior)

Question 24

Axis during dynamic sacral motion (walking)?

Answer 24

Oblique axes

Question 25

Axis during postural motion?

Answer 25

Middle transverse axis (S3)

Question 26

When L5 is SB, what sacral axis is engaged and where?

Answer 26

Oblique axis on the same side as side bending

Question 27

When L5 is rotated, the sacrum rotates which way?

Answer 27

Opposite on an oblique axis

Question 28

Where is the seated flexion test positive in sacral SD?

Answer 28

Opposite the oblique axis

Question 29

B/l sacral flexion or extension move around what sacral axis?

Answer 29

Middle transverse

Question 30

What is a common sacral dysfunction in the postpartum patient?

Answer 30

B/l sacral flexion

Question 31

What axis does the sacrum rotate in a sacral margin posterior SD?

Answer 31

Mid-vertical or parasagittal

Question 32

What is treated first, L5 or sacrum?

Answer 32

L5