Effects of hand vibration on reflex behaviors and pain perception - A pilot study

Abstract This research investigated the effects of hand vibration on the protective reflex responses and perception of the stimulus intensity. Electrical pulses were applied to the wrist to elicit the reflex responses. Changes of the reflex response were measured using the surface electromyographic activities from the hand flexor muscles, and were analyzed as a function of vibration frequency and initial level of grip force. Psychophysical experiment was also performed to assess the effects of hand vibration on perception of the electrical stimulus. The reflex responses were stronger during vibration, and were more visible at lower vibration frequencies and higher muscle contraction level. During vibration, a poor correlation was found between the reflex responses and stimulus perception. Relevance to Industry Results suggesting to adopt low level of grip exertion (light-weighted tool) and high vibration frequency to minimize the vibration-induced change of the protective reflex behaviors are useful to tool manufacturers and related workers.