A new study published in the journal Scientific Reports indicates that perceptions of stiffness or pain in the back may not reflect the actual state of the spine or muscles.
Dr. Tasha Stanton, senior research fellow at the University of South Australia's School of Health Sciences in Adelaide and her team researched the neuroscience behind clinical pain by applying measurable pressure to the spine of 15 patients with self-reported feelings and symptoms of chronic lower back pain, and an additional 15 healthy, age-matched control group.
The researchers found "People with chronic back pain and stiffness overestimated how much force was being applied to their backs - they were more protective of their back. How much they overestimated this force related to how stiff their backs felt - the stiffer [it] felt, the more they overestimated force. This suggests that feelings of stiffness are a protective response, likely to avoid movement."
"In theory," Dr. Stanton explained, "people who feel back stiffness should have a stiffer spine than those who do not. We found this was not the case in reality. Instead, we found that that the amount they protected their back was a better predictor of how stiff their back felt."
Furthermore, the researchers "found that these feelings could be modulated using different sounds. The feeling of stiffness was worse with creaky door sounds and less with gentle whooshing sounds."
"This raises the possibility that we can clinically target stiffness without focusing on the joint itself but using other senses," said Dr. Stanton, "The brain uses information from numerous different sources including sound, touch, and vision, to create feelings such as stiffness."
"If we can manipulate those sources of information, we then potentially have the ability to manipulate feelings of stiffness. This opens the door for new treatment possibilities, which is incredibly exciting," she concluded.