U. NOTTINGHAM (UK) — Arthritis pain can be significantly reduced—and in some cases even temporarily eliminated—by an illusion.
By tricking the brain into believing an aching hand was being stretched or shrunk, researchers were able to reduce by half the pain felt in 85 percent of people tested.
The research could lead to future technologies to help patients improve mobility by reducing the amount of pain they experience while undergoing physical therapy.
Researchers from the University of Nottingham stumbled on the findings by chance during a community day in 2010.
As part of the event, members of the public were invited to experience body distortion illusions using technology which takes a real-time video capture image of a hand and uses computer manipulations combined with physically pulling or pushing to fool the brain into believing the hand is stretching or shrinking.
“During the course of the day the grandmother of one of the children wanted to have a go, but warned us to be gentle because of the arthritis in her fingers,” says Catherine Preston, who is now at Nottingham Trent University and collaborated on the study.
“We were giving her a practical demonstration of illusory finger stretching when she announced ‘My finger doesn’t hurt any more.’ We were just stunned—I don’t know who was more surprised, her or us.”
Researchers then engaged 20 volunteers from an osteoarthritis support group with an average age of 70, all who had been clinically-diagnosed with arthritic pain in the hands and/or fingers.
Before starting the test they were asked to rate their pain on a 21-point scale, with 0 indicating no pain and 20 representing the most unbearable pain imaginable.
The team then compared the body illusion to just physically pushing and pulling on the painful parts of the volunteers’ hands to test the effect on their pain. Other control tests were conducted by stretching or shrinking a non-painful part of the hand and visually enlarging or reducing the whole hand.
The results showed a marked reduction in pain—on average halving the discomfort for 85 percent of volunteers. Some reported greater reduction in pain for stretching, some for shrinking and some for both. The pain reduction only worked when painful parts of the hand were manipulated.
Further, stretching or shrinking the painful part of the hand temporarily eliminated pain in one-third of all volunteers. Anecdotally, many volunteers also reported an increased range of movement.
The results are reported in the journal Rheumatology.
The research could be the first step toward new technologies for physical therapy, allowing health professionals to reduce the pain for sufferers while exercising joints. Less expensive technology could allow a low-cost model of the system for home use.
“This research is an excellent example of how fundamental research can often produce unexpected and significant results, says Roger Newport who is leading the study. This “could be extremely important to the millions of people who suffer from this painful and debilitating illness.”
More news from University of Nottingham: http://communications.nottingham.ac.uk/News.html