Sacroiliac Mobilization, Part 1: Assessing for Fixation and Correcting Iliosacral Joints
By Marc Heller, DC
Editor's note: This is the first in a series of three articles on adjusting the pelvis. This column started as an in-depth description of various low-force adjusting methods. I have occasionally strayed, but low-force adjusting is the essence of what I share.Let's start with diagnosis and assessment of the whole of the pelvis, and then briefly talk about correcting the outer ring.
If I divided my chiropractic career of 30 years in half, I might say that the first half focused on hypomobility, learning how to assess and adjust stuck joints, and the second half focused on hypermobility, learning how to assess which joints are hypermobile, and how to use rehab and other tools to correct excessive motion. Even within hypermobility, there are usually some hypomobile joints; correcting their lack of motion unloads the hypermobile joints. If the patient has a weak disc, if they have a tendency toward SI hypermobility, it will be worse if that weak joint is required to move too much to make up for the lack of movement in another joint.
A recent article in this publication by Malik Slosberg1 points to one study that suggests inhibited multifidi can be activated by an adjustment. All of us have clinically noted how adjustments improve function in the lower back, but this study is useful as evidence-based confirmation. The article could easily be misinterpreted, however. It is a huge reach to draw a conclusion that adjustments are enough or that adjustments will retrain the core. The bulk of the evidence on improving core function is based on a training approach, teaching the person to use their core differently.
It's way too easy to assume that your favorite tool, the adjustment, will fix everything that is wrong. Don't assume that adjustments will correct all inhibited or tight muscles. Either learn and use rehab, or refer out for PT, Pilates or good functional training. The sacroiliac complex is intimately involved in load transfer, such as when we walk, lift, and perform many other daily activities. Correcting motor-use patterns via rehab is critical to a stable and functional sacroiliac.
I have always been a palpator; I have always used variations on motion palpation to assess for stuck joints. After studying the muscle energy model of the pelvis for at least the fourth time, I have concluded that my previous assessment tools for the pelvis were inadequate. If I did my usual testing, prone and supine springing of the ilium and the sacrum, I would miss some of the key restrictions. I am once again back to using the muscle energy model for the pelvis. This seems particularly critical when the sacral side of the joint is locked. (You'll have to wait for the second part of this series for the details of those sacral assessments and corrections.)
Diagnosis and Assessment
For any SI problem, you will need to use all of your diagnostic skills and look at the accumulation of the evidence. We do not have a single gold-standard test. There is mixed evidence on the utility of tests that attempt to find joint restriction. I find that SI problems usually correlate with tenderness, either in the joint line itself or just lateral, in the origins of the sacral parts of the gluteal muscles, and the long dorsal SI ligaments. The iliolumbar ligament and the sacrotuberous ligaments also seem to correlate well with SI problems. (I detailed the anatomy and palpation of these structures in a previous DC article.)2
The sacroiliac can appear to be misaligned in many lower back cases. My experience is that the SI tends to compensate for many other dysfunctions. Correcting an anterior superior ilium over and over again does not necessarily solve the problem. From a motion palpation/manipulation perspective, my first question is: what is fixated? What structures are not moving?
I have gone back to starting with the Gillet (Stork) test. This is probably one of the first motion palpation tests I learned in school, more than 30 years ago. One of the keys to consistent palpation results is to keep it simple.
The patient is standing in front of you. I have one of their hands touching a waist-high surface, either in front or to the side. I am not testing balance, and I want to eliminate that variable. Ideally, touch the skin directly. For the right side, the pad of your right thumb contacts the PSIS. The pad of your left thumb is about 1 inch medial, over the sacrum. The shafts of your thumbs face each other, so that you create an imaginary horizontal line.
The patient starts by lifting their right leg (bent at the knee), as high as they comfortably can. They have to lift it fairly high to induce motion into the sacroiliac joint. This assesses the right iliosacral side of the joint. Does the PSIS drop inferior? If it does, the joint is moving. If the PSIS and sacrum stay relatively level, motion is not occurring at that joint. Don't make it complicated. Keep it simple. You are looking for patient-initiated motion strictly in the vertical plane. Yes, other motions may occur, but just ignore them.
The second test assesses the sacral side of the joint. The doctor keeps the same two-thumb contact on the right side. The patient now lifts the left leg (knee bent) as high as they comfortably can. Does the sacral side, under your left thumb, move inferior? If it does, is normal motion occurring? If not, the joint is stuck.
Next, the patient stays in same position and you move your thumbs over the left side of the joint, and repeat the test. Left leg lift indicates left iliosacral. Right leg lift indicates left sacral side of the joint.
This test will not tell you about hypermobility, instability or core stability. It will give you a good solid indicator of lack of motion of the four basic components of the posterior sacroiliac joints. It assesses both the right and the left side, and it differentiates which side of the joint is not moving. You can have one or more stuck joints, or a normally moving pelvis.
When I first studied muscle energy, I was confused by the terminology, differentiating the sacral side versus the iliosacral or ilial side of the joint. I think I understand that better now. In relation to the iliosacral side of the joint, we are looking at the ilial motion on a relatively fixed sacrum. This is involved in the non-weight-bearing side's motion: the swing phase of the gait. When you kick or when you stride forward, the hip asks the pelvis to move with it. To assess this for the right side, we lift the right leg.
The sacral side of the SI is more involved with weight-bearing, with stance. When your weight is on the right leg and your left leg is flexing forward, the sacral side of the right sacroiliac joint is called upon to move. When we assess this for the right side, we stand on the right side and lift the left leg. The right leg is now the stance side. These simple tests try to break down the complication of life's movements into simple functional tests.
Correcting the Iliosacral Fixation
Let's talk about "most missed" pieces of the outer ring. For the iliosacral, the obvious restrictions are the sagittal rotations, the anterior-superior ilium or the posterior-inferior ilium. Most of us also assess what muscle energy calls flares, or what Gonstead called IN or EX; the transverse plane rotations of the ilium on the sacrum. Our chiropractic language does not seem to usually include shears, a superior or inferior motion.
In muscle energy terminology, these are called upslips and downslips. These are not physiological motions, whereby the joint gets stuck at end range, but aberrant non-physiological motions, usually related to trauma. The indicators for this become clear when you assess the position of the various landmarks.
In a sagittal rotation, on the anterior side, the ASIS goes anterior inferior, and the PSIS moves superior. In an upslip or downslip, the whole ilium has moved in relation to the sacrum, so the front and the back landmarks move in the same direction. In other words, rather than seeing rotation, you are seeing a shear, a superior or inferior movement of the ilium on the sacrum. Check these landmarks with the patient supine; the height of the ASIS, the iliac crest, and the pubes. While prone, check the height of the inferior portion of ischial tuberosity and the PSIS. The joint itself, either the upper or lower aspect of the SI joint, will usually be tender to the touch in a shear.
To determine whether the lesion is an upslip or a downslip, you first need to identify the side of the fixation. This is where the Gillet test comes in; you can assess whether the iliosacral side of the joint is stuck. If the superior side is stuck, the problem is an upslip. If the inferior side of the joint is stuck, it's a downslip.
Correcting an upslip is relatively simple. It can be done either supine or prone. It does involve an impulse, a sudden movement. Have the patient's leg in internal rotation, to lock the hip joint. If the patient has good knees, you can pull on the lower leg. If they have iffy knees, pull on the thigh. Your pull is quick, and is directly inferior. I rarely hear an audible release. If you have been effective, the tenderness will immediately change, and the landmarks will now be level. These corrections usually hold well, although in patients with ligamentous laxity, or significant core inhibition, the problem can easily recur. I wrote a whole article on shears earlier, and my corrections have remained about the same, so you may want to look at the iliosacral diagnosis article referenced below.3
Part 2 of this article (Dec. 16, 2010 issue) will explore fixations on the sacral side of the SI joint.
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