Sacrum I

Question 1

What is the composition and function of the sacrum?

Answer 1

Composition: 5 separate segments that were fused early in life
Function: protects reproductive organs

Question 2

Which ligaments stabilize the sacrum by limiting motion?

Answer 2

• Sacrospinous
• Sacrotuberous
• Ventral/Anterior sacro iliac
• Dorsal/Posterior sacroiliac

Question 3

True or False: The sacrum and L4 have an intimate relationship

Answer 3

False: The sacrum and L5 have an intimate relationship

Question 4

The base of the sacrum projects forward and articulates with a lumbar vertebrae to form the…

Answer 4

lumbosacral ange.

Question 5

What muscles are associated with the sacrum?

Answer 5

Piriformis
Iliacus
Obturator internus
Quadratus femoris
Superior and Inferior gemelis
Iliopsoas
Erector spinae

Question 6

A tight piriformis is responsible for what symptom?

Answer 6

Sciatica

Question 7

An iliacus in spasm can cause what to happen to the sacrum?

Answer 7

rotation of the sacrum.

Question 8

L5 rotations also rotate …?

Answer 8

the sacrum

Question 9

Describe the sacrum in relation to the pelvis.

Answer 9

The sacrum is suspended between the ilia by three true and three false ligaments. The sacroiliac joints are L-shaped joints that allow gliding in rotation on the order of millimeters.

Question 10

True or False: Movement of the sacrum is produced only by ligaments, not by muscles.

Answer 10

True

Question 11

The most cephalad part of the sacrum is called the …?

Answer 11

base.

Question 12

The most caudad part of the sacrum is called the…?

Answer 12

apex

Question 13

The superior poles are ….. and …. to the PSIS.

Answer 13

medial and superior to the PSIS’s

Question 14

Just cephalad to the ILA’s on the sacrum bone are the……?

Answer 14

inferior poles.

Question 15

Lateral and cephalad to the coccyx are the….

Answer 15

inferior lateral angles (ILAs)

Question 16

The superior transverse axis is at what level? What is the Superior transverse axis involved in?

Answer 16

S1;

the superior transverse axis is involved in respiratory flexion and extension synchronous with sphenobasilar (Cranial flexion and extension).

Question 17

The middle transverse axis is at what level? What does the middle transverse axis allow for?

Answer 17

S2;

The middle transverse axis allows for postural flexion and extension that is coupled with but opposite the direction of lumbar flexion and extension

Question 18

What does the inferior transverse axis allow for?

Answer 18

rotation of the ilia on the sacrum during walking = iliosacral motion.

Question 19

During inspiration, what direction does the base and apex of the sacrum move?

Answer 19

base moves posterior

apex moves anterior

Question 20

During exhalation, what direction does the base and apex of the sacrum move?

Answer 20

base moves anterior

apex moves posterior

Question 21

True or False: Motion occurs along an axis, not around the axis.

Answer 21

False; Motion does not occur along an axis, it occurs AROUND an axis.

Question 22

Which axis is responsible for rotation of the sacrum?

Answer 22

Vertical axis.

Question 23

Which axis, which is perpendicular to the plane of the sacrum, has side bending occur laterally around the axis?

Answer 23

anterior-posterior axis

Question 24

What axis runs from the upper part of the sacroiliac articulation to the lower part on the opposite side and occurs naturally when shifting weight from one foot to another?

Answer 24

oblique axis

Question 25

When diagnosing a sacral dysfunction via static testing, what are you looking for?

Answer 25

sacral suclus depths and position of inferior lateral angles (cephalad vs. caudad and anterior vs. posterior)

Question 26

When diagnosing a sacral dysfunction motion testing, what tests can you perform?

Answer 26

• Seated flexion test
• lumbar spring test
• backward bending (Sphinx) test
• Respiratory movements of sacrum
• Passive motion testing of sacrum

Question 27

What does the seated flexion test tell you? When will you have a false negative?

Answer 27

The seated flexion test identifies the SI joint that is stuck.

Since it finds dysfunctions that are unilaterally dominant, you will have false negative in dysfunctions that affect both SI joints.

Question 28

What does the lumbar spring test tell you?

Answer 28

A positive (hard end feel/resistance) in a dysfunction in which all or part of the base is stuck posterior.

Question 29

What does the backward bending (sphinx) test tell you?

Answer 29

Because backward bending should move the base anteriorly, findings are described as more symmetrical or less symmetrical (more asymmectrical).

Dysfunctions resulting in a part of the sacral base getting stuck posteriorly become more asymmetrical.

Dysfunctions resulting in a part of the base getting stuck anteriorly become more symmetrical

Question 30

What does the respiratory movement of the sacrum test tell you?

Answer 30

The sacrum will move freely in whichever respiratory cycle that it is held in. So, movement means that the sacrum is held in that cycle. ??