The mechanism question
What is better? Spinal manipulation or self-management of an acute low back injury…
One of the recurring challenges in rehabilitation is distinguishing the effectiveness of an intervention from the explanation offered for its effectiveness.
Suppose a patient feels better after spinal manipulation.
That improvement is real.
But the response doesn't establish that a vertebra was repositioned, a joint was corrected, or a specific mechanical dysfunction was resolved.
Those are separate mechanistic claims.
Similarly, improvement following biopsychosocial self-management doesn't establish that changing beliefs was the sole cause of improvement.
The intervention may influence activity, confidence, expectations, coping, behavior, or other factors.
The PACBACK trial evaluates clinical outcomes (spinal manipulation was not more effective than self-management for low back pain)..
It doesn't identify one definitive mechanism.
It just displays an outcome from an intervention.
It’s valuable information, but don’t let the story limit the possibilities.