Ratio scaling of pain perception with the submaximum effort tourniquet technique.

The submaximum effort tourniquet technique (SETT) is becoming more widely used as part of the clinical assessment of chronic pain patients despite little information about the scaling of this technique. Ratio scaling procedures resulted in a linear function, presumed to underlie clinical application of the SETT, for only 11% of the subjects. Therefore, current clinical use of the tourniquet ratio score should be questioned. Normals also obtained significantly more negatively accelerated power functions than pain patients with no difference in tolerances. Differences in these growth curves are discussed with reference to the concept of pain endurance. Continued needs for standardized pain evaluation techniques suggest that this type of psychophysical scaling procedure may improve the precision of some clinical pain assessments.