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.