We have three questions to answer here:
- What does dry needling actually do, and are there any effects beyond a credible placebo treatment?
- What does the evidence say in regards to the efficacy of dry needling in the treatment of painful musculoskeletal conditions?
- Considering the type of treatment it is and the totality of the evidence we have to date, is dry needling a treatment physical therapists should utilize?
If you have been following the plot until now, you most likely have a good idea how to answer these questions. The most plausible explanation for what dry needling does on a physiological level is that the treatment decreases pain intensity through a combination of both specific and non-specific effects. As for the specific effects, it is unclear exactly what mechanisms are in play and how much they actually contribute to pain relief. Based on the high-quality placebo-controlled trials that showed largely equivocal results, it is reasonable to conclude that the majority of the effect dry needling has is, in fact, from non-specific factors, i.e. placebo. This would explain why there are changes in something that we measure subjectively like pain, and why we do not see any significant changes in other outcomes that are more objective.
Considering the mechanisms most likely in play during a dry needling treatment, it is unsurprising that the research is largely mixed. Many of the trials and reviews we looked at suggest that when comparing dry needling to other treatments or placebo treatments, the two treatment conditions were either equivocal or dry needling was worse. In the studies that had positive results in favor of dry needling, there was always some sort of catch; they did not obtain statistical significance, they achieved statistical significance but they failed to reach clinical significance, there was a poor placebo design, there were no differences at time periods later on, there were a very low number of subjects, there was poor blinding, or there was a large amount of adverse events like, pain, bruising, or bleeding. There is no well-controlled studies that I have seen that suggest dry needling has any effect beyond non-specific, short-term pain relief.
There is another huge body of research that we need to pay attention to: acupuncture. Proponents of dry needling argue that dry needling is not acupuncture, citing differences in technique, methodology, and the physiological premises on which the treatment is based. Despite some philosophical and theoretical differences, it is essentially comes down to the same thing. Both acupuncturists and dry needlers treat painful musculoskeletal conditions by sticking needles in spots that hurt. The physiological events that occur afterwards (whatever they actually are) still occur, regardless of what the practitioner thinks is happening. A rose by any other name is still a rose. And unfortunately for the dry needlers, the research in support of acupuncture is also largely mixed. As David Colquhoun has put it so bluntly, “acupuncture is theatrical placebo” (Calquhoun, 2013).
“The best controlled studies show a clear pattern, with acupuncture the outcome does not depend on needle location or even needle insertion. Since these variables are those that define acupuncture, the only sensible conclusion is that acupuncture does not work” (Calquhoun, 2013).
If you want to make the case that dry needling is different than acupuncture, and thus the evidence for acupuncture does not apply, I need to hear why and how it is different, and how that difference translates into better patient outcomes.
Now, as physical therapists, is this the type of treatment we want to adopt? Should this be another tool in the tool belt?
Dry needling is a passive intervention that may relieve pain largely through non-specific mechanisms of action. This type of treatment takes away agency from the patient, has not been shown to have long-term and clinically meaningful effects, and brings us a bit closer to the black hole of snake oil treatments, bad evidence, and pseudoscience. Dry needling is not a treatment that should be adopted by physical therapists because it is not physical, in the sense we ought to care about it, it is not therapeutic beyond short term pain relief, and it it is not well supported by science.
For patients that are interested in this type of treatment, why not just refer them to a knowledgeable acupuncturist? We shouldn’t be denying patient preferences, and this seems like the ideal way to accommodate that desire. Acupuncturists are probably more highly trained than we are, have the time to do as thorough a “treatment” as necessary, and it would give us more time to focus on what we ought to do best: provide meaningful, targeted exercise programs for our patients that improve their physical and mental capacity and ultimately make their lives better.
- Colquhoun, D., et.al. (2013) Acupuncture is Theatrical Placebo. Anesthesia and Analgesia, Volume 116, Issue 6