This series of experiments demonstrates that experiencing stiffness in the back does not reflect its actual biomechanical properties. Instead, feeling stiff involves multiple sensory systems meddling perception, serving a protectory purpose.
It was shown that: 1) there is no difference in objective measures of back stiffness between people who are feeling stiff and people who are not; 2) those who are feeling stiff overestimate forces to their spine, but on the other hand are better in detecting changes in applied force; and 3) this process of interference can be modulated using auditory cues synchronous to applying forces.
No significant correlations were found between perceived stiffness and objective stiffness, and there were no significant differences in objective stiffness between those who had back pain and feelings of stiffness and the controls.
People with feelings of stiffness did overestimate the forces applied to their spine, and were better able to detect changes in forces. This can be seen as a protective response, which prevents excessive range of motion or sudden movements that can cause re-injury.
Finally, synchronous auditory input influences feelings of stiffness, underlining the important and very much two-way interaction between sensory input and bodily awareness.
> From: Stanton et al., Sci Rep 7 (2017) 9681 . All rights reserved to The Author(s). Click here for the online summary.
This research group has used an elegant series of experiments to test hypotheses arising from previous studies, that are questioning nature of the previously established link between sensory input and perception.
Although the results may not be so surprising, because they have become increasingly speculated on in recent literature, they provide hard evidence that our approaches of managing chronic low back pain should be reviewed ? and that there may very well be unorthodox ways of engaging other sensory input that can be considered as a serious treatment option.