Neck pain can be changed through altered visual feedback

Using virtual reality to misrepresent how far the neck is turned can actually change pain experiences in individuals who suffer from chronic neck pain, according to research published in Psychological Science, a journal of the Association for Psychological Science.

It may seem like our experiences of pain stem from some objective, physiological source, but research has shown that many factors - including sensory, cognitive, and emotional cues - can have a significant influence on if, when, and how we feel pain. These new results indicate that altering the visual cues that inform the brain about the body can impact pain:

"Our findings show that the brain does not need danger messages coming from the tissues of the body in order to generate pain in that body part - sensable and reliable cues that predict impending pain are enough to produce the experience of pain," says researcher G. Lorimer Moseley of the University of South Australia. "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."

Moseley, co-author Daniel Harvie, and colleagues recruited 24 chronic neck pain sufferers from physiotherapy clinics.

The participants had experienced the pain for an average of 11 years, stemming from issues including posture, tension, repeated strain, trauma, and scoliosis.

The researchers had participants sit in a chair while wearing a virtual reality head-mounted display (Oculus Rift). The display showed a virtual indoor or outdoor scene while simultaneously recording participants' head movements using gyroscopes. The participants wore a seatbelt that prevented them from moving their torso and they also wore headphones that blocked out incidental noise.

The neck (cervical spine) is composed of vertebrae that begin in the upper torso and end at the base of the skull. The bony vertebrae along with the ligaments (which are comparable to thick rubber bands) and muscles provide stability to the spine. The muscles allow for support and motion. The neck has a significant amount of motion and supports the weight of the head. However, because it is less protected than the rest of the spine, the neck can be vulnerable to injury and disorders that produce pain and restrict motion. For many people, neck pain is a temporary condition that disappears with time. Others need medical diagnosis and treatment to relieve their symptoms.

For each scene that was presented, the participants were asked to rotate their head, either to the left or to the right, until they experienced pain. What the participants didn't know was that on some trials the researchers were manipulating the visual feedback provided in the virtual world so that it didn't accurately represent the degree to which the head was turned. In some cases, the scene indicated that participants weren't turning their head as far as they actually were - it understated the degree of rotation. In other cases, the feedback indicated to participants that they were turning their head farther than they were, overstating the degree of rotation.