Assessment of coarse and fine hand motor performance in asymptomatic subjects exposed to hand-arm vibration

Martin B Popević,Petar Bulat,Lazar R Tenjović,Aleksandar P.S Milovanović,Srđan M Janković,Slavica R Jovičić,Srđan S Borjanović

doi:10.2478/10004-1254-65-2014-2403

Abstract

A frequently encountered exposure profile for hand-arm vibration in contemporary occupational setting comprises workers with a long history of intermittent exposure but without detectable signs of hand-arm vibration syndrome (HAVS). Yet, most of the published studies deal with developed HAVS cases, rarely discussing the biological processes that may be involved in degradation of manual dexterity and grip strength when it can be most beneficial - during the asymptomatic stage. In the present paper, a group of 31 male asymptomatic vibration-exposed workers (according to the Stockholm Workshop Scale) were compared against 30 male controls. They were tested using dynamometry and dexterimetry (modelling coarse and fine manual performance respectively) and cold provocation was done to detect possible differences in manual performance drop on these tests. The results showed reduced manual dexterity but no significant degradation in hand grip strength in the exposed subjects. This suggests that intermittent exposure profile and small cumulative vibration dose could only lead to a measurable deficit in manual dexterity but not hand grip strength even at non-negligible A(8) levels and long term exposures.

Highlights

A frequently encountered exposure profile for hand-arm vibration in contemporary occupational setting comprises workers with a long history of intermittent exposure but without detectable signs of hand-arm vibration syndrome (HAVS)
Our pilot study analyses the differences in hand performance between the healthy subjects and those with the vibration exposure profile comprising workers that have a long history of intermittent vibration exposure, yet exhibit no detectable signs of HAVS
The present study dealt with workers exposed to intermittent vibration, asymptomatic with regard to HAVS according to the Stockholm Workshop Scale [1]

Summary

Introduction

A frequently encountered exposure profile for hand-arm vibration in contemporary occupational setting comprises workers with a long history of intermittent exposure but without detectable signs of hand-arm vibration syndrome (HAVS). A group of 31 male asymptomatic vibration-exposed workers (according to the Stockholm Workshop Scale) were compared against 30 male controls They were tested using dynamometry and dexterimetry (modelling coarse and fine manual performance respectively) and cold provocation was done to detect possible differences in manual performance drop on these tests. The asymptomatic workers with intermittent handarm vibration (HAV) exposure receive little to no attention in the literature They routinely pass the screening tests with 0SN, 0V score according to the Stockholm Workshop Scale [1]. The absence of symptoms in no way implies the absence of vibrationinduced damage, as the vibration energy is dissipated in tissues, producing not so observable effects These changes in asymptomatic workers are subtle and the available literature on the risk of accidents at the workplace is scarce. Our pilot study analyses the differences in hand performance between the healthy subjects and those with the vibration exposure profile comprising workers that have a long history of intermittent vibration exposure, yet exhibit no detectable signs of HAVS

Methods

Results

Discussion

Conclusion