Abstract:
The psychophysical relationship between the magnitude of pressure on thirteen test locations of twenty
healthy subjects’ feet with four probe areas at three indentation speeds and the corresponding perceived
sensations were analyzed. The dependency of pressure pain thresholds (PPT) on area, A, and speed, v, can
be mathematically modeled in the form, PPTi ¼ [ai þ bLn(v)]Ab i ¼ 1,2.13 where b and b are constants
and are dependent on location and gender, and ai is a constant highly correlated with foot tissue stiffness.
The relationship between the sensory intensity to pressure magnitude appears to follow a modified
Stevens’ power law with power exponents less than 1.0 and consistent across the 13 test locations with
a mean of 0.82 and a range from 0.67 to 0.98. This particular model helps to understand the sensation of
pressure threshold and its impact in the design of consumer products.
