AN UPDATED REVIEW OF EPIDEMIOLOGIC STUDIES ON THE RELATIONSHIP BETWEEN EXPOSURE TO WHOLE-BODY VIBRATION AND LOW-BACK-PAIN

The aim of this paper is to update the information on the epidemiologi c evidence of the adverse health effects of whole-body vibration (WBV) on the spinal system by means of a review of the epidemiologic studie s published between 1986 and 1996. In a systematic search of epidemiol ogic studies of low back pain (LBP) disorders and occupations with exp osure to WBV, 37 articles were retrieved. The quality of each study wa s evaluated according to criteria concerning the assessment of vibrati on exposure, assessment of health effects, and methodology. The epidem iologic studies reaching an adequate score on each of the above mentio ned criteria, were included in the final review. A meta-analysis was a lso conducted in order to combine the results of independent epidemiol ogic studies. After applying the selection criteria, 16 articles repor ting the occurrence of LBP disorders in 19 WBV-exposed occupational gr oups, reached a sufficient score. The study design was cross-sectional for 13 occupational groups, longitudinal for 5 groups and of case-con trol type for one group. The main reasons for the exclusion of studies were insufficient quantitative information on WBV exposure and the la ck of control groups. The findings of the selected studies and the res ults of the meta-analysis of both cross-sectional and cohort studies s howed that occupational exposure to WBV is associated with an increase d risk of LBP, sciatic pain, and degenerative changes in the spinal sy stem, including lumbar intervertebral disc disorders. Owing to the cro ss-sectional design of the majority of the reviewed studies, this epid emiologic evidence is not sufficient to outline a clear exposure-respo nse relationship between WBV exposure and LBP disorders. Upon comparin g the epidemiologic studies included in this review with those conduct ed before 1986, it is concluded that research design and the quality o f exposure and health effect data in the field of WBV have improved in the last decade. (C) 1998 Academic Press.