Joint Displacement

The SI joint moves only millimeters in normal function, making reliable palpatory detection of millimeter-level displacement through multiple soft tissue layers unsupported. Palpation-based assessment of spinal and SI joints has poor inter-rater and intra-rater reliability, undermining clinician claims of detecting displacement. Individual anatomical variation means two clinicians examining the same patient may consistently identify different palpatory findings. True joint displacement occurs almost exclusively in the context of significant trauma, not in routine clinical presentations. Traumatic shoulder dislocation requires emergency care with anesthesia for reduction because pain and muscle guarding make unanesthetized reduction infeasible. Telling patients their joint went out of place and was put back creates maladaptive illness beliefs about instability and fragility.