Not much is known about the physiologic mechanism of dry needling. Although some evidence suggests that dry needling may decrease nocioceptive sensitivity and facilitate muscle function, no studies to date have examined these physiologic changes compared to clinical outcomes. The objective of this study was to examine changes in lumbar multifidus (LM) muscle function and nociceptive sensitivity after dry needling in patients with LBP and to determine if such changes vary in patients that exhibit improved disability (responders) and those that do not (non-responders). Patient responders showed greater improvements in LM muscle contraction and nociceptive sensitivity 1 week, but not immediately, after dry needling than non-responders.
These results indicate that there may be lasting and clinically relevant sensorimotor changes that occur in LBP patients that improve with dry needling treatment that partially account for the physiologic mechanism of action.