Neck Pain Determined by Visual Cues

Virtual reality experiments determined that the threshold of pain is increased when the participants do not know the degree of rotation is manipulated.

Changes in neck pain can be altered through visual feedback, according to research published in Psychological Science.

Researchers from the University of South Australia observed 24 chronic neck pain sufferers from various physiotherapy clinics in order to determine if pain would occur at a lesser degree of head rotation when visual feedback overstated true rotation.

They additionally wanted to find out if pain would occur at a greater degree of rotation when visual feedback understated the true rotation. The patients had an average of 11 years of pain, which stemmed from a variety of factors like posture, tension, repeated strain, trauma, and scoliosis.

The patients were instructed to sit in a chair wearing a virtual reality head mounted display (Oculus Rift), which then recorded the patients’ head movements. A seatbelt prevented the patients from moving their torsos, and they wore headphones to block out incidental noise.

Participants were asked to rotate their heads to interact with the scene. They were unaware, however, that the researchers were manipulating some of these scenes to trick the participants into rotating more or less than the participants believed they were.

“The brain does not need danger messages coming from the tissues of the body in order to generate pain in that body part — sensible and reliable cues that predict impending pain are enough to produce the experience of pain,” researcher G. Lorimer Moseley, PhD explained in a press release. “These results suggest a new approach to developing treatments for pain that are based on separating the non danger messages from the danger messages associated with a movement.”

The participants were able to turn their heads 6 percent farther than they normally would be able to when the researchers understated the actual head rotation. When the researchers overstated head rotation of the participants, their pain free range shrank by an average of 7 percent. The patients did not report any differences in the intensity of pain across the various conditions, which the researchers believe is important.

“We were surprised at how robust and predictable this pattern of results was,” Moseley continued. “If cues signaling danger amplify or indeed trigger pain, then these cues present a novel target for therapy.”

Previous research has indicated that external signals can influence the intensity of pain experiences, which this study supported. But these results are novel because external signals additionally can increase the threshold at which pain is experienced, the authors commented.