Hand dominancy--a feature affecting sensitivity to pain.

Hand dominancy (i.e. handedness) is a factor that should be considered for further characterizing individual variations in sensitivity to pain. The aim of the present study was to examine the contribution of handedness and gender to sensitivity to tonic cold pain in healthy subjects. Participants were 109 healthy volunteers (52 males and 57 females), of whom 65 were right-handed and 44 left-handed. Subjects were exposed to the cold pressor test (1 degrees C) for both hands while measuring the cold pain threshold, intensity, and tolerance. No significant differences were found in pain threshold or intensity between the right versus the left hands among either the right-handed or the left-handed subjects. However, among the right-handed subjects only, cold pain tolerance was significantly longer in the right hand than in the left hand (32.9+/-5.1s vs. 27.0+/-4.2s, respectively; p=0.018). Significant differences were found between males and females in pain threshold, but not in pain intensity or tolerance, either when their right or left hand was tested (p=0.027 and p=0.009, respectively). Analyzing pain perception by handedness and gender revealed that the right-handed males were less sensitive to pain in their right versus their left hand, as determined by lower pain intensity (p=0.031) and longer tolerance (p=0.047). No significant differences were found among the left-handed males or among the females. The results provide further evidence that handedness is one vital feature that should be considered more often when designing a psychophysical study. This may lead towards improving the translation of laboratory research findings to the clinical setting.