The Truth About The SI Joint That You Shouldn’t Ignore
Early on in my career, I’d have people come in with hip pain and like it was a script, I had an explanation ready.
I had a couple of go-to orthopedic tests, (Gillet’s, Standing Flexion, and Supine To Sit) and I’d boast about how their Ilium was rotated to their Sacrum. This, of course, resulted in a leg length discrepancy and had to be the source of their pain!
I’d do a muscle energy technique that would cause a loud “pop” from their pubic symphysis and this look of relief would wash over the patient’s face as if I had just done some sort of magical repair.
But, as time goes on not only have I started to realize that most of the above concepts were wrong, I was SUPER wrong for believing I was doing some magical repair (I’d like to think my ego has shrunk since then).
So, the question begs, what’s really going on with this darn S.I joint!?
Well…here’s what I’ve found out.
Rotation Of The Ilium
Whenever we talk bout the ilium rotating we are discussing nutation and counternutation.
Nutation is when the sacrum is moving in anterior/inferior…think to nod your head. The interosseous sacroiliac ligament (which is one of the strongest in the body) connects the sacrum and the ilium and prevents this movement from happening.
Counternutation is the opposite, moving in posterior/superior…think looking up at the ceiling. The posterior sacroiliac ligament connects the PSIS and the iliac crest with the sacrum and also prevents counternutation.
This is essentially what we were told to test in college and it was all about how the ilium rotated on the sacrum. So, we have to ask the question, how much rotation can there be?
The degree of movement is typically measured through the axis of rotation occurring through the second sacral vertebrae so the sacrum is performing its nutation or counternutation in the sagittal plane (the body in half from head to toe). The amount of movement is thought to be anywhere between 15° and less than 3°.
There is even discrepancy as to the direction of movements as one study showed that when a patient is forward flexing (like we do for some of the SI special tests) the sacrum was just as likely to nutate as it was to counternutate.
However, there are extenuating circumstances that would allow more movement in the joint such as those who have S.I. Joint disorders (which we will get into later), but when we look at healthy individuals who are perhaps experiencing some pain in the area we see much different numbers. One study actually showed in healthy individuals the average total rotation was only around 2°. They even examined 25 patients with sacroiliac joint syndrome and found the movement range to only be 1-3° with no difference between the symptomatic and asymptomatic side.
When we look at a goniometer or a protractor to see what 1-3° looks like, it’s pretty minimal and I dare say REALLY difficult to see with the naked eye.
So, we have to ask the question, are the aforementioned orthopedic tests accurate or valuable for us to use?
Well, a systematic review showed the use of Gillett’s test to evaluate movement of the SIJ to have a 47% intertester reliability, which shows this test to be unreliable. Because the movements are so limited and minute it is even suggested the movement would be impossible to see.
Even if we’re doing tests to look for some sort of dysfunction, another review showed the most typical tests used were: Faber, distraction/compression test, focal SIJ tenderness, seated and standing Gillett’s, femoral shear, and modified Gaenslen’s were not reliable to show the likelihood of SIJ tenderness unless three or more of those provocation tests were positive, the pain was unilateral, the pain is below L5 without lumbar pain, or if pain increases with rising from sitting.
Now that’s a lot to take into account especially if there is no history to suggest any kind of a pain or dysfunction disorder.
Of course, some of our patients will be referred for imaging, but even that isn’t helpful in the evaluation of SIJ pain unless looking for tumors, infection, or fracture, but hopefully, you’ve ruled some of this out with your intake by ruling out red flags.
What Should We Be Looking For?
If we look at a broader term, pain around the SIJ can be referred to as Pelvic Girdle Pain Disorders (PGP).
Specifically, when we look at this, the cause is around pregnancy, trauma, arthritis, and/or osteoarthritis, but excludes things like gynecological and urological disorders.
Pregnancy is one of the factors that we know can influence women to experience PGP as the effect of hormones (higher serum levels of relaxin and progesterone) affects the ligaments in the pelvis to increase their laxity, and possibly influences stability of the pelvis, but more research is needed to clarify how the role of hormones may differ in various presentations. However, this decreased joint stability can be compensated for by a change in muscle function. There is also evidence to show some of the risk factors associated with developing PGP during pregnancy is a previous history of low back pain and previous trauma to the pelvis.
When it comes to specific pathological issues like inflammatory arthritis, sacroiliitis, fractures, or infections there’s really not much we can do as therapists as manual therapy can’t address the underlying pain mechanism of the disorder, so, much of what we are doing is most likely helping with symptoms as opposed to rectifying the cause.
Beyond these specific pathological issues there is another group of issues classified as Non-specific pelvic girdle pain disorders:
- Non-specific inflammatory pelvic girdle pain disorder
- constant, disabling, non-remitting pain in SIJ, provoked with weight-bearing, pelvic compression, and SIJ provocation tests.
- Peripherally mediated (mechanically induced) pelvic girdle pain
- Localized pain to SIJ that in intermittent and provoked and relieved by specific postures and activities due to directional loads and weight-bearing.
- Usually, they have a clear mechanism or time of onset due to repeated strain or direct trauma.
- Reduced Force Closure
- Associated with excessive strain to the SIJ coupled with motor control deficits of muscles that do force closure of the joints (pelvic floor, transverse abdominus, lumbar multifidus, iliopsoas, gluts).
- Common with postpartum PGP and a positive ASLR (active straight leg raise) test.
- Functional impairment associated with, sitting, standing, walking, or activities that induce rotational pelvic strain coupled with spine or hip loading activities like cycling, or rowing.
- Excessive Force Closure
- Localized pain to SIJ and surrounding tissues, along with positive pain provocation tests.
- Result of excessive, abnormal, and sustained loading of sensitized SIJ
- Negative ASLR
- Compression and local muscle activation (pelvic floor, transverse abdominal wall, back muscles, glutes, iliopsoas) is provocative.
- Commonly associated with the belief the pelvis is ‘unstable’ or ‘displaced’ but exercise, massage (although I wouldn’t recommend this for the pelvic floor as massage in this area is out of our scope), stretching helpful for pain relief.
- Psychological influences on peripherally mediated pelvic girdle pain
- May be associated with underlying stress and anxiety.
- It can be associated with faulty beliefs, and passive coping strategies, so we have to promote accurate beliefs, relaxation, and active coping strategies.
- If associated with positive beliefs, and active coping strategies, then focus can be on physical impairments and work on helping with pain control.
- Central nervous system driven pelvic girdle pain disorders
- Associated with widespread, severe, and constant pain that is non-mechanical.
- High levels of physical impairment, social impact, and abnormal pain behaviours.
- Dominant psychosocial factors (catastrophizing, fear, anxiety, depression, history of sexual abuse).
- Requires a multidisciplinary approach with medical and psychological management.
- Genetics
- People with PGP are more likely to have a mother or sister affected.
- Possibly a social influence here as well.
While this may seem like a lot to take in, it actually simplifies things for us.
If there is no history of pregnancy, trauma, or inflammatory issues (which we should be able to rule out fairly quickly in our intake process), then we can look at psychosocial factors influencing their pain.
Now, I know where many are going with this…we can’t treat psychosocial (or many arguing it’s not in our scope).
Well, maybe we can’t treat it directly (okay for sure we can’t, refer out to a mental health professional for that) but we can recognize their influence and work on our treatment and communication from there. Many of these conditions revolve around beliefs, stress, anxiety, catastrophizing, depression, fears, and social impact. We can most certainly address these things by giving some proper education around what they are experiencing. Explaining to them, their hip isn’t ‘out’, their ilium isn’t rotated, they don’t have an inflammatory disease, and pain is normal. Giving them relaxation techniques, helping with symptom modification, and coping strategies can all have a large impact on helping our patients with SIJ pain. However, more importantly ‘promoting accurate beliefs’, might be one of the most important things we can do. All too often we have patients come in who have been told they’re rotated, out, or misaligned, which puts the responsibility on us to educate and correct those beliefs. Sadly, I used to be one of the practitioners telling them this. If I could go back and apologize to them I would, but many of those people I don’t see in my practice anymore. While I can hope this is because I helped and they’re doing better (and I probably did with some of them), I hope that whoever they are seeing now isn’t reinforcing those old narratives, but is giving them more accurate information. I know the way I treat SIJ now, is different than the way I did 10 years ago and now that you have this information, I hope it changes the way you do because updating our narrative is part of our responsibility as healthcare professionals.
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Hi Jamie!!
Love this article. It’s very interesting and pertinent and confirms what we have discovered ourselves here at our clinic. My business partner, an osteopath and athletic therapist has realized a discrepancy in the understanding of the “core” muscles (pelvic floor and transverse are under-rated when we mention core) and she pursued training as a Pilates instructor because Pilates (Stotts) was very much focused about that core pillar that creates stability (which is why a lot of professional dancers practice pilates)… Stability while widely projected arm & leg movements which the dancers are also saying took care of their SIJ problems and their back issues.
Now, for myself, I realized that if only I could find a way to inhibit overused compensating muscles and activate the weak muscles, the rehab process dramatically shortened. I went and studied under Dr. Poney Chiang (neuro-meridian acupuncture) who has done multiple studies and research regarding acupuncture points targeting nerve trunks, motor points, trigger points and sensory nerves to “reset” the system. We use estim with specific frequencies depending if it’s motor or sensory. This allows the whole rehab/exercise and strengthening portion to accelerate.
I’d be happy to share what we find out on our side too! But I am not so fluent & patient to write up such beautiful articles as yours. Keep writing, I’ll keep reading!! Good job Jamie!
Julie
Thanks Julie