Hand-arm frequency-weighted vibration effects on tactility

Abstract

This study reports results of an investigation into the short-term effects of power hand tool vibration on deep sense tactile sensitivity. Five subjects operated a simulated hand tool using a 30 s / 30 s work / rest duty cycle. The handle vibrated at ISO 5349 weighted accelerations of 8 m / s2, for frequencies of 20 Hz, 80 Hz, and 160 Hz, in three orthognal directions. A no-vibration condition was also included for a control. Tactile sensitivity of the distal index finger was measured after 30 minutes using a ridge detection threshold detection task. The average falling ridge threshold increased five times from 0.01 mm for the no-vibration condition to 0.05 mm at 160 Hz, however no rising ridge threshold shifts were observed. Implications for job design and work practices are discussed.