Low back pain among different groups of subjects exposed to hand-arm transmitted vibration.

OBJECTIVES

The purpose of this study was to investigate the prevalence of low back pain (LBP) among various groups of subjects exposed to hand-arm transmitted vibration, and to compare the prevalence of LBP of these subjects with that of non-exposed groups.

METHODS

The subjects of this study were 13 groups of males and 3 groups of females of working population leaving in a certain city located in the central part of Japan. By means of a questionnaire, interviews, field visits, or annual health examination, information on age, working career, working posture, various types of tools used, and experience of having LBP during the 12 months preceding the completion of the questionnaire were collected. The subjects' age ranged between 22 and 69 years. All subjects were classified into 5 categories, and the prevalence of LBP was obtained for them.

RESULTS

On the whole, complaints of LBP among male and female green tea and strawberry farmers were most frequent. There was a large variation (16.0-72.2%) in the prevalence of LBP among subjects operating vibrating tools. Among three groups of health care professionals, the prevalence of LBP was in the range of 36.5-53.0%. The senior doctors had less complaints of LBP. The prevalence of LBP among subjects who had sedentary jobs was in the range of 41.7-45.9%, and almost as high as that in blue-collar workers using vibrating tools. The prevalence of LBP among females exposed to hand-arm transmitted vibration was between 26.1 and 63%. The prevalence rates of LBP among vibration exposed subjects were plotted against the vibration magnitude of tools used by the same subjects reported in our previous study; however, no significant correlation could be obtained between the prevalence of LBP and vibration values.

CONCLUSIONS

Exposure to segmental vibration is less likely to be a risk factor in increasing prevalence of LBP. A higher prevalence of LBP in some groups provide strong evidence for a dominant work-related etiology in developing LBP. Regarding data presented in this study and by a review on scientific literature, suggestions for improving working posture were presented. It seemed that to decrease the risk of LBP among these subjects, special attention should be paid to stimulating the adoption of an ergonomic working posture and to ergonomic training.