[Effects of individual features on the measurement of vibration perception thresholds: standard setting for healthy people]

The thresholds of vibration perception in healthy people may differ significantly depending on individual and constitutional features: age, weight, height, race and gender, and also on various addictions like smoking or alcohol abuse. These variables have not as yet been analyzed in setting Polish standards of vibration perception thresholds used for therapeutical and certification purposes. The aim of the study was to develop a model that could render it possible to assess the normative values of vibration perception, taking account of individual features. The study covered 187 healthy persons free from exposure to vibration. Two methods were used to determine vibration perception thresholds: the standard Polish method and the method based on the ISO 13091-1/2001 standard. The methods differed in the technical parameters (contact force of vibrating probe 1.2 N and 0.1; probe diameter 12 and 5 mm-standard method and the method according to ISO, respectively), the presentation of stimuli (ascending method versus von: Bekesy method) and their frequencies. Vibration perception thresholds were significantly influenced by age (within the range of 63-250 Hz-standard method; 4-250 Hz-method according to ISO), body mass (full range of frequencies--standard method; 4-125-method according to ISO) and height (single frequencies--both methods). A model for determining vibration perception thresholds, taking account of age, height and body mass of study subjects, was developed. The results of the study show that individual and constitutional features should be taken into consideration when interpreting the results of the vibration perception examinations conducted for the purpose of occupational disease certification.