If a clinician has told you your sacroiliac (SI) joint is “out of alignment,” “rotated,” or “unstable,” that language matters more than you might think, and not in a good way. In Boulder County, we’re seeing a resurgence of clinicians using outdated tests to explain low back, hip, and even distant pain by way of SI joint position. The evidence moved away from this framework about 20 years ago. Here we review some key points about the SIJ.
Your SI Joint Doesn’t Move Out of Place
A landmark 1998 study in Spine (Tullberg et al.) used Roentgen stereophotogrammetry, a high-precision method for measuring 3D motion in skeletal joints, to image patients before and after SI joint manipulation. Positional tests changed afterward, but the imaging showed no change in the joint itself. A more recent study (de Toledo et al., 2020) used motion analysis in 30 healthy men and reached the same conclusion: high-velocity, low-amplitude manipulation doesn’t change SI joint mobility or position.
The Tests Used to “Find” This Aren’t Reliable
Part of why the alignment theory persists is that the clinical tests used to support it were never that trustworthy. The amount of movement available at the SI joint is exceedingly small, smaller than palpation can reliably detect, and bony landmarks vary enough between people that “asymmetry” is often just normal anatomy. Multiple studies have found the reliability and validity of these positional tests to be worse than a coin flip, which makes them a poor basis for any clinical decision, let alone an explanation you’re given about why you hurt.
What You’re Told Changes How You Heal
Manual therapy helps reduce SI-related pain, but the mechanism has little to do with structural repositioning. Its effects are largely neurophysiological: changes in the nervous and endocrine systems and in muscle behavior, rather than anything mechanical shifting back into place.
This is where language becomes clinically important. Being told your SI joint is “out of alignment” or “unstable” can plant the idea that your body is fragile, which tends to promote avoidance behavior and worsen prognosis, a pattern known as the nocebo effect. The opposite approach, with reassurance that there’s no structural damage, collaborative decision making, and manual therapy combined with movement and exercise, consistently leads to better recovery.
What a Good Evaluation Looks Like
A thorough, evidence-based exam starts with detailed questioning about your pain and history, then a physical exam that uses techniques the research supports, not static palpation of bony landmarks. At Mend, your physical therapist works with you to find the source of your pain and the impairments contributing to it, then builds treatment around manual therapy, targeted exercise, and clear education about what’s going on.
To see how manipulation holds up as a treatment even without repositioning anything, read SI joint manipulation works, just not how you think, and for the broader treatment evidence, see what the research says about PT for SI joint pain.
If you’ve been told your SI joint is out of alignment and want a second opinion grounded in current evidence, an evaluation that skips the outdated tests is the right next step. Book an SI joint evaluation at Mend’s Boulder or Lafayette clinic.
Browse more on sacroiliac joint pain and manual therapy, or see the full Orthopedic Care library.
References
Tullberg T, Blomberg S, Branth B, et al. Manipulation does not alter the position of the sacroiliac joint: a roentgen stereophotogrammetric analysis. Spine. 1998;23:1124-1128.
de Toledo DFA. Behavior of sacroiliac joint mobility in individuals subjected to osteopathic manipulation of the ilium. UNISUAM. https://sstcc.unisuam.edu.br/index.php/ppgcr/article/view/97
