How do you convince someone they have had dry needling when they haven’t? Easy – you use a magician and the power of suggestion.
That was the tactic employed by UniSA PhD physiotherapy candidate Felicity Braithwaite to help create a placebo, or “sham”, for dry needling so the technique can be scientifically tested.
Unlike medical drug trials, where sugar pills provide the perfect placebo, the process becomes more complicated when physical interventions need to be trialled.
“Somehow, we need to convince participants that they have had a real physical treatment when they haven’t,” Felicity says.
The solution? Call in the magicians and tap into the art of deception.
Dry needling – a western form of acupuncture – is now frequently used in the physiotherapy and allied health fields. It involves needles being inserted into muscle where pain is felt, with the aim of bringing relief. However, a credible sham is needed to provide a way of scientifically testing the effects.
Sham interventions are simulated experiences used in empirical studies to compare the real treatment with the false treatment.
Felicity recruited experts from a range of fields, including research methodology, dry needling, hypnosis and deception to devise a convincing placebo for dry needling.
The result? A practical experiment which fooled both therapists and recipients.
In dry needling, needles are encased in a plastic shield which is laid on the skin and tapped to guide each needle into specific pain points.
The sham needles used were shorter than the real ones so did not pierce the skin, but because they were encased in a plastic guide tube neither therapist nor participant could tell the difference.
The other deception used was a piece of foam in the sham guide tube simulating human tissue, which gave therapists tactile feedback.
Magician Gary Edwards said his input was more psychological than mechanical.
“We developed some scripts about what a therapist could say to people receiving the treatment,” he says.
“They were told it was a new type of needle, very fine, and that they may not feel anything. Whether they did or not was of no consequence, so participants were not under any pressure to report a sensation. That was critical to the success of the trial.”
Another tactic – often employed by magicians – was to distract the participants from the process by asking them questions while they were being treated.
“Our brain can’t absorb too many things at once so if people are thinking about something they are less likely to pay attention to what else is happening – in this case, a needle being inserted. Doctors and magicians use this technique all the time,” Edwards says.
“Basically, our job in this experiment was to get people to believe something that was not true.”
A total of 15 therapists experienced in dry needling and 45 ‘healthy’ recipients (with no pain) took part in the trial. Remarkably, almost 60 per cent of the therapists could not tell the difference between the real and sham treatments and 51 per cent of the recipients were also fooled.
“This demonstrates the importance of cognitive influences over tactile sensations in blinding recipients,” Felicity says. “Researchers have used magicians before to understand how the brain works but, to my knowledge, this is the first time they have been used to develop a placebo.”
The findings contest the widely-held belief that placebos pose an insurmountable challenge in physical intervention research, she says.
The next step is to use the sham in an actual trial to determine whether dry needling works beyond placebo effects.
Felicity’s research was supported by an Australian Government Research Training Program scholarship. She has recently submitted her thesis for examination.