ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

1aBV5. Changes in mechanoreceptor-specific vibrotactile thresholds with ongoing occupational exposure to hand-transmitted vibration.

A. J. Brammer

J. E. Piercy

Inst. for Microstruct. Sci., Natl. Res. Council Canada, Ottawa, ON Canada

S. Nohara

Asahi Mutual Life Insurance Co., Fukui, Japan

H. Nakamura

Tokushima Univ., Tokushima, Japan

The purpose of this paper is to explore the influence of occupational exposure to hand-transmitted vibration on mechanoreceptor acuity, for possible future use as a screening test for early symptoms of the hand--arm vibration syndrome (HAVS). Mechanoreceptor-specific vibrotactile thresholds were determined using the tactometer at frequencies mediated by the SAI receptors (4 Hz), FAI receptors (32 Hz), and FAII receptors (100 Hz) [A. J. Brammer and J. E. Piercy, ``Measuring vibrotactile perception thresholds at the fingertips of power-tool operators,'' Proc. U.K. Informal Group Meeting on Human Response to Vibration, Buxton (1991)]. Thresholds were obtained from 33 seasonal operators of chain saws and brush cutters, who had so worked for up to 39 years. Twenty-three of the workers were judged clinically to suffer from mild to moderate symptoms of HAVS. A progressive reduction in acuity with increasing years of exposure was observed, on average, in this group, for each mechanoreceptor population. A reduction in acuity remained even after correcting for changes in threshold with age.