Ischial
tuberosity
Sacral
sulcus
Median sacral
crest
Iliac crests at
level of L4
Inferior lateral
angle
Sacral base
Figure 8.4slopes of the posterior superior iliac spines (PSIS), illustrated in Figure 8.4. Y o u can find the PSIS by looking for the dimples most p e o p l e have in this area, located about two inches lateral to the lumbosacral junction. By placing the pads of your thumbs over them you will find the most pos- terior aspect of the PSIS. Drag your thumbs in an inferior direction until you find the inferior slopes of the PSIS. You will know you are there when you feel your thumbs just begin to slide off the inferior aspect of the PSIS. With your client standing, place the pads of your thumbs on the infe- rior slope of the PSIS and ask him to b e n d forward as far as he comfort- ably can. Watch what h a p p e n s to y o u r thumbs. If there is an iliosacral fixation, o n e of your thumbs will ride up in a superior direction and the o t h e r o n e will stay where it is. T h e side on which the t h u m b rides up is the fixed side. Figure 8.5 shows the restriction on the right side. This test works quite well, unless the hamstrings or the quadratus l u m b o r u m are asymmetrically tight. If the hamstrings are tight on the side opposite to where your t h u m b rides up, or if the quadratus l u m b o r u m is tight on the same side as where your t h u m b rides u p , the superior m o v e m e n t of your t h u m b will not be a true indicator.
in-flared or out-flared, whether o n e i n n o m i n a t e is up-slipped or d o w n - slipped, whether o n e is anteriorly slipped or posteriorly slipped, or whether o n e is posteriorly torsioned or anteriorly torsioned. T h e tests will only tell you the side on which the innominate is fixed on the sacrum. In o r d e r to tell what kind of iliosacral fixation you are looking at you must palpate a n u m b e r of other areas on the pelvis, a technique that will be described shortly. For now, just practice the standing flexion test and notice what happens to your thumbs.
Now that you have learned h o w to use this test to determine iliosacral dysfunction, you can use the sitting version of it to h e l p y o u d e t e r m i n e unilateral sacroiliac fixations. Ask your client to assume a seated position, o n c e again place the pads of your thumbs on the inferior slope of the PSIS, and ask him to forward b e n d as far as he comfortably can. If o n e of your thumbs rides superiorly, as it d o e s in Figure 8.6, y o u have discovered a sacroiliac fixation. Like the standing flexion test, the sitting flexion test only tells you on which the side the sacral fixation exists, it d o e s n ' t tell whether it is fixed in anterior/posterior torsion or anterior/posterior shear.
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T h e sitting flexion test effectively removes the influence of your client's legs and pelvis on the sacrum and there- f o r e allows y o u to d e t e r m i n e whether sacroiliac fixations are present. In c o n - trast, the standing flexion test adds the influence of the pelvis and legs, and lets y o u d e t e r m i n e whether iliosacral fixa- tions are present. If your t h u m b rides up in both the sitting and standing flex- i o n tests, then y o u have d i s c o v e r e d a sacroiliac a n d iliosacral dysfunction. Knowing h o w to use these tests is help- ful to sorting out what kind of fixations are present.
Often you may be working with clients w h o s e low b a c k p r o b l e m s create t o o m u c h pain w h e n they try to forward b e n d from a standing position. In these cases, and as a way to d o u b l e c h e c k your results, the so-called stork test is also very useful. Ask your client to stand facing a wall so he can stabilize himself while performing the test. Put the pad of your right thumb on the posterior aspect of his right PSIS and your left thumb at the same level on the median sacral crest, which is basically the mid-line of the sacrum. Ask your client to raise his k n e e to at least 90 degrees and watch what your right t h u m b does (Figure 8.7). If there is no iliosacral fixation, your right t h u m b will ride inferiorly as he raises his leg and y o u r left t h u m b will remain where it is. If there is a fixation, then your right thumb will remain where it is and n o t m o v e inferiorly. Test the other side in the same way. Place your left t h u m b on the posterior aspect of his left PSIS and your right t h u m b at the same level on the medial sacral crest, ask him to raise his knee to at least 90 degrees, and watch h o w your left t h u m b responds. If it doesn't m o v e inferiorly, you have discovered an iliosacral fixation.
If either the standing flexion or the stork test reveals an iliosacral fix- ation, the next part of your evaluation requires you to figure out by means of palpation whether you are dealing with flare, shear, torsion, or a cora- Figure 8.7
bination of some or all of them. Let's take a simplified l o o k at an exam- ple. Suppose you find an iliosacral fixation on the right by using the stand- ing flexion test, and you palpate the innominates to discover that the right innominate seems out-flared and the left seems in-flared. If you had pal- pated the innominates without having p e r f o r m e d the standing flexion test, it would be very difficult for you to be able to say whether the right innominate was out-flared or the left innominate was in-flared. But since you p e r f o r m e d the standing flexion test and it revealed that the fixation was on the right, y o u can c o n c l u d e that the right i n n o m i n a t e must be fixed in an out-flared position. So here is h o w it works: first you determine the side on which the fixation is present; then y o u palpate to determine whether the iliosacral fixation is an in-flare or out-flare, an anterior or pos- terior shear, an up-slip or down-slip, an anterior or posterior torsion, or some combination.