Sacrum

Question 1

The sacral promontory is the anterior portion of ____

Answer 1

S1

Question 2

ILA =

Answer 2

Inferior lateral angle (of the sacrum)

Question 3

Do any muscles move the sacrum directly?

Answer 3

No! “The sacrum is mostly a stabilizer, an anchor, a foundation…”

Question 4

List the muscles/connections of the sacrum:

Answer 4

Piriformis (2nd-4th sacral segments)

Iliacus (superolaterally)

Pelvic diaphragm (particularly coccygeus, anteriorly to sacrotuberous &sacrospinous ligaments)

Aponeurosis of the erector spinae and Latisimus dorsi (posterior-medial surface)

Gluteus Maximus (ILA)

Question 5

Function/innervation of the piriformis:

Answer 5

Externally rotates, slight extension, and abductor of the hip when the hip is flexed; S1/2

Question 6

Lumbosacral angle (aka Ferguson’s angle) details:

Answer 6

The angle is generally between 25-35 degrees

An increase in this angle can increase lumbosacral strain

Question 7

Two main landmarks for sacral diagnosis:

Answer 7

Sacral sulci (slightly medial and superior to the PSIS’s) and the ILA (most posterior/inferior aspect of sacrum, attachment of gluteus maximus)

Question 8

L5 rule in Anglund’s terms

Answer 8

“the concept that L5 and the sacrum rotate in opposite directions”

Question 9

Describe the seven axes of sacral motion:

Answer 9

1 vertical: allows for left/right rotation
1 Anterior-posterior: allows for sidebending
3 Transverse: Allows for flexion and extension.
2 oblique axes: Combines rotation, sidebending, and flexion/extension.

Question 10

Describe the superior transverse axis (thoracic respiratory axis)

Answer 10

S1/S2 interspace

Flexion and Extension occurs with respiration:
The sacrum flexes with exhalation
The sacrum extends with inhalation

Question 11

Describe the middle transverse axis (postural or sacroiliac axis)

Answer 11

Level of S2, at the anterior convexity of the upper and lower limbs of SI joint

Flexion and extension occurs with motion of the sacrum on the ilium

Question 12

Describe the inferior transverse axis (iliosacral axes) (3 of them)

Answer 12

Located at level of S3, at the posterior-inferior part of the inferior limb of SI joint

Flexion and extension occurs with motion of the ilium on the sacrum

Question 13

All three of the transverse axes allow for what (bottom line)?

Answer 13

Flexion and extension

Question 14

Oblique sacral axes are named for the _______ aspect

Answer 14

superior

Question 15

“when you have a left axis, the ______ _______ is moving”

Answer 15

right base

Question 16

The lumbar spine sidebends _______ to the weighted foot

Answer 16

ipsilateral (due to QL contraction)

Question 17

Describe SI joint dysfunction and inhibition of the glut max and medius

Answer 17

This shortens the stride… the hamstrings are the recruited and overused to help extend the hip and leg… the erector spinae are also recruited and overused

Question 18

What is the L5 rule?

Answer 18

In sacral torsion, the sacrum and L5 rotate opposite each other

Question 19

Describe forward sacral torsions (Type I)

Answer 19

These occur with NEUTRAL mechanics in the lumbar spine

Question 20

Describe backward sacral torsions (Type II)

Answer 20

These occur with NON-Neutral mechanics in the lumbar spine

Question 21

In a left on left sacral torsion, it is expected that L5 is rotated to the ______ and side bent _____

Answer 21

R right, SB left

Question 22

A positive spring test will always give you a _______ problem.

Answer 22

posterior

Question 23

If forward motion of the sacral base is present, the spring test would be _______

Answer 23

negative