Vibrotactile Perception at Glabrous and Nonglabrous Skin of Fingers: Repeatability of Measurements and Changes Induced by Acute Vibration Exposure

Objectives: We sought to determine the within-session and between-session repeatability of vibrotactile perception threshold (VPT) measurements and the response patterns in VPT induced by acute exposure to short-term vibration from grasping a vibrating handle, at both glabrous and nonglabrous skin of fingers. Methods: Baseline VPT was recorded twice at glabrous and nonglabrous side of fingers in the right hand of eight healthy volunteers. Then, the subjects were exposed to three exposure conditions (vibration at 31.5 Hz and 250 Hz, and no vibration), from gripping a vertical handle by the right hand, conducted on 3 different days at an interval of 1-3 wk. After exposure, the subjects released the hand and further VPT measurements at each location were made. Results: Compared to the nonglabrous side, VPT measurements at the glabrous side demonstrated better within-session and between-session repeatability with lower coefficient of repeatability and higher intraclass correlation coefficient. After exposure, a significant increase in VPT was noted under both 31.5 Hz and 250 Hz (p<0.05-0.001) exposure conditions in the glabrous finger. In the nonglabrous finger, a pronounced increase in VPT was revealed under 250 Hz exposure condition (p=0.05). Conclusions: While measuring VPT at glabrous and/or nonglabrous fingers, the importance of the site of measurement should be considered; the repeatability for such measurements appears to be better at the glabrous site. At high frequency, vibrotactile perception appears to be affected in both glabrous and nonglabrous skin from acute vibration exposure.