The Scaroiliac Joint

Question 1

The pelvis consists of two ____ joints and one _____ joint., for a total of three joints.

Answer 1

2 sacroiliac joints

1 pubic symphysis

Question 2

The sacral surface is composed of _____, whereas the ilial surface is composed of _____.

Answer 2

Sacral surface = hyaline cartilage

Ilial surface = fibrocartilage

Question 3

What makes the SI joint unique compared to all other joints?

Answer 3

Only 1 muscle crosses the SI joint surface.

Question 4

_____ is the only muscle that crosses the SI joint surface.

Answer 4

Piriformis

Question 5

True or False: Joint motion at the SI joint is more influenced by the contractile tissue than arthrokinematics motion.

Answer 5

FALSE

More influenced by arthrokinematics motion

Question 6

Describe 2 ways in which movement is defined at the SI joint.

Answer 6

1. Motion as the ilium moves on the sacrum = ILIOSACRAL motion
2. Motion as the sacrum moves on the ilium = SACROILIAC motion

Question 7

Normal iliosacral motion entails moving the ilium into ___ and into ____.

Answer 7

Anterior rotation

Posterior rotation

Question 8

The most common SI impairments involve ____ motion.

Answer 8

Iliosacral motion

Question 9

What are the 2 most common iliosacral impairments?

Answer 9

Anterior (rotation / torsion) and Posterior (rotation / torsion) innominate (which are positional faults)

Question 10

What is an upslip/downslip?

Answer 10

An abnormal iliosacral motion where one innominate moves either in a cranial or a caudal direction in relation to the other innominate.

Question 11

How many axes of motion are present at the sacroiliac joint?

Answer 11

6

Question 12

What is nutation?

Answer 12

Anterior movement of the superior aspect of the sacrum in conjunction with posterior movement of the inferior aspect of the sacrum, or anterior sacral tilt.

Question 13

What is counternutation?

Answer 13

Posterior movement of the superior aspect of the sacrum in conjunction with anterior movement of the inferior aspect of the sacrum, or posterior sacral tilt.

Question 14

Sacral nutation is the same motion as bilateral ____, and sacral counternutation is the same motion as bilateral _____.

Answer 14

ilial posterior rotation

ilial anterior rotation

Question 15

How does movement at the SI joint aid in childbirth? (2)

Answer 15

1. When the sacrum moves into counternutation, the rim of the pelvis widens and the outlet narrows. This facilitates movement of the baby toward the outlet.
2. When the sacrum moves into nutation, the rim of the pelvis narrows and the outlet widens. This facilitates expulsion and delivery of the baby.

Question 16

The prevalence of SI joint problems is ~___ %.

Answer 16

25%

Question 17

List 6 things that may cause SI joint problems.

Answer 17

1. Pregnancy / childbirth
2. Trauma
3. Degenerative joint disease
4. S/P lumbar fusion
5. Hypermobility
6. Positional Faults

Question 18

____ is the hormone released into the bloodstream that causes ligaments to become more lax.

Answer 18

RELAXIN

Question 19

______ must be ruled out when assessing SI joint dysfunction.

Answer 19

Ankolysing spondylitis

Characterized by a gradual fusion of the vertebrae, beginning at the lower spinal segments and progressing upward

Question 20

Describe the position of the ASIS and PSIS in patients with iliosacral impairments with anterior torsion and posterior torsion (2).

Answer 20

1. The patient with an anterior torsion should have a lower ASIS and a higher PSIS on the side of the impairment.
2. The patient with a posterior torsion should have a lower PSIS and a higher ASIS on the side of the impairment.

Question 21

The patient with a sacroiliac motion positional fault could have ____ in their sacrum. What 2 structures should be palpated to assess for this positional fault?

Answer 21

ASYMMETRY

Palpate

1. Sacral sulci
2. Inferior lateral angle

Question 22

If the patient has a positional fault into sacral nutation, the ____ should be deeper than ‘normal’, whereas if the patient has a positional fault into sacral counternutation, the ______ will be deeper than ‘normal’

Answer 22

Sacral sulci

Inferior lateral angle

Question 23

Lumbar forward bending can provoke a _____ torsion positional fault, while lumbar backward bending can provoke a ____ torsion positional fault.

Answer 23

Lumbar Forward bending = POSTERIOR torsion

Lumbar Backward bending = ANTERIOR torsion

Question 24

_____ of the ASIS causes a stretch at to the posterior SIJ ligament, while _____ of the ASIS causes stretch to the anterior SIJ ligament.

Answer 24

Compression = stretch posterior SIJ
Distraction = stretch anterior SIJ

Question 25

Weakness in what 3 muscles can contribute to anterior torsions at the SI joint?

Answer 25

Abdominal muscles
Gluteus maximus
Hamstrings

Question 26

Weakness in what 4 muscles can contribute to posterior torsions at the SI joint?

Answer 26

Paraspinals
Iliopsoas
Rectus femoris
TFL

Question 27

In general, tests involving either palpation for position or mobility of the sacroiliac joint are associated with ____ reliability.

Answer 27

POOR

Question 28

What number of positive special tests is needed to rule in a diagnosis of SI joint involvement? (2)

Answer 28

3 out of 6 special tests must be positive

2 out of 4 special tests must be positive

Question 29

List the 4 special tests, for which 2 must be positive, to rule in SI joint pathology.

Answer 29

Distraction
Compression
Thigh thrust
Sacral thrust

Question 30

List the 6 special tests, for which 3 must be positive, to rule in SI joint pathology.

Answer 30

Distraction
Compression
Thigh thrust
Sacral thrust
Gaenslen’s Test left side
Gaenslens’s Test right side

Question 31

List 4 interventions used to treat SI joint pathologies.

Answer 31

1. Joint manipulations/mobilizations (regardless of whether the joint is hypermobile)
2. Trunk strengthening exercises
3. Patient education regarding positioning to avoid asymmetric postures
4. Sacroiliac belt to provide added stabilization