Influence of vibration exposure on tactile and thermal perception thresholds

Abstract

Aims To establish if intermittent exposure to hand-transmitted vibration had the same effect as continuous exposure on the temporary response of finger tactile and thermal perception thresholds. Methods Two laboratory experiments were conducted. In each, 10 healthy subjects, five males and five females, participated. The subjects' fingers were exposed to vibration under four conditions with a combination of different periods of exposure and rest periods. The vibration frequency was 125 Hz and the frequency-weighted acceleration was 5 m/s 2. A measure of the tactile or thermal perception was conducted before the different exposures to vibration. Immediately after the vibration exposure, the acute effect was measured continuously for the first 75 s. This was followed by regular measures for a maximum of 30 min. Results The results showed that combinations of vibration with different periods of exposure and rest periods significantly influenced vibrotactile perception, but not thermal perception. Conclusions These findings suggest that intermittent exposure to hand-transmitted vibration might be more beneficial for the response of the finger vibrotactile sensation than continuous exposure. This finding is inconsistent with the evaluation methods in ISO 5349-1 for vibrotactile sensation, but accurate for thermal perception.

International consensus criteria for diagnosing and staging hand–arm vibration syndrome

“…Each hand to be staged separately; Raynaud type blanching to be confirmed by a validated photograph with blanched skin clearly demarcated from unaffected skin; blanching score to be calculated from the photographs as 3 for proximal, 2 for middle and 1 for distal phalanx of each affected finger; neurosensory symptoms to be considered pathological if lasting > 20 min (Burstrom et al 2009); sensory perception to be assessed on the pulps of two or more digits supplied by the median and ulnar nerves; standardised methods of testing must be followed for all tests and compared with appropriate controls…”