- The diagnosis and assignment of causality of sacroiliac joint (SIJ) pain to movement dysfunction is an erroneous linear thought process, unsupported by current knowledge.
BACKGROUND & OBJECTIVE
This perspective article by a global panel of academic and clinical physical therapists explored the current clinical trends in the diagnosis and then management of non-specific sacroiliac joint (SIJ) related pain. Implicated in 16-35% of “low back pain” presentations (1), therapists have traditionally sought to include/exclude the SIJ as a nociceptive source and then implicate SIJ movement dysfunction(s) as causal to symptoms. The fundamental linear thought errors and potential negative consequences of explaining SIJ pain to patients through a pathoanatomical and movement dysfunction lens were highlighted. Suggestions that would enable a shift towards a narrative based on contemporary research and critical thinking were made. Pregnancy and specific pathology-related SIJ pain were excluded in this article.
Implying SIJ Involvement: Local Tissue Sensitivity at the SIJ
The SIJ is highly innervated. Pain associated with sensitised SIJ structures can be diagnosed accurately with validated SIJ pain provocation tests holding high levels of sensitivity (94%) and specificity (78%) (2). This increased SIJ tissue sensitivity may be subsequent to tissue loading, however this is an incomplete interpretation of the pain experience. Clinically, SIJ movement tests are then routinely performed and problematically labelled as causal to local SIJ sensitization. This mechanistic thought process has been challenged for quite some time however still pervades therapy (3). The patient may then onboard the erroneous belief that their pain is attributable to movement dysfunction(s) at the SIJ.
Inconsistent messages may be delivered when a therapist uses manual therapy to increase movement in the SIJ yet gives home exercises to increase “core stability”.
Explaining SIJ Pain As a Consequence of SIJ Movement Dysfunction: Is This Plausible? Movement dysfunction around the SIJ is often taught to indicate hypomobility or alternatively instability in the SIJ. Despite ongoing widespread use, the tests for SIJ movement dysfunction have proven unreliable and should be considered unusable (4,5). Therapists routinely deluding themselves that they can detect minute movements in the SIJ are encouraged to attribute these perceptions to other factors such as soft tissue motion, and pain associated muscle activation patterns.
In dispelling the disabling concept of “SIJ instability”, it is imperative that therapists appreciate that the SIJ is inherently stable due to:
- Radiostereometric analyses indicate that SIJ movements are less than 0.3mm (4).
- Keystone architecture of the sacrum between the 2 innominate bones plus reciprocal congruency of articular surfaces.
- Extensive intra and extra articular ligaments.
- Gravitational loading contributes to stability.
Evidence That Nociceptive Activity From The SIJ Contributes To Pain
Recent SIJ denervation procedures have highlighted that nociceptive SIJ activity can contribute to the pain experience but is only part of a complex multi-dimensional experience of pain. Denervation being no better than exercise at three months (7).
Should we dispense with movement dysfunction models for the SIJ? Substantial research has shown that motor patterns alter at the onset of acute lower back and pelvic pain, and should be considered a natural response. Motoric changes are then influenced