Aim: Because of the revision of the relevant
directives (e.g. VDI 2057-1:2002), a re-assessment
of whole-body vibration is necessary.
In a reanalysis of the “Epidemiological Study
Whole-Body Vibration” (WBV-study), which
was supported by the DGUV*, the new evaluation
approach has been applied to the old
data in order to analyze how different threshold
values and durations of exposure affect
the risk of developing a lumbar syndrome.
Methods: Various exposure parameters were
re-calculated and evaluated for the 388 participants
of the WBV-study who were exposed
to vibration. Relationships between these data
and the medical diagnoses were studied by
means of regression analysis, the application of
threshold values was analyzed with regard to
the influence of level and duration of exposure.
Results: Logistic regression analysis demonstrated
that all the various parameters of
daily vibration exposure were quite good
predictors of the target variable “lumbar
syndrome”. The assessment acceleration awy(8)
yields the highest odds ratios, but the daily
exposure A(8) also performs well. When the
total doses of exposure to vibration during
a working life are calculated and the prevalence
of lumbar syndrome in groups with
different doses is compared, the risk proves
to depend heavily on the chosen threshold
criterion: e.g., for a threshold value of A(8) =
0.63 m/s², a significant increase of the ageadjusted
prevalence is observed between the
non-exposed subjects and those exposed to
this daily vibration value for up to 10 years
(age-corrected prevalence ratio: PVRMH = 1.5;
CI95: 1.1/2.0) and those exposed to more than
the 16-year accumulated dose (PVRMH = 1.7;
CI95: 1.2/2.5).
Conclusions: The daily exposure A(8) proves
to be a good predictor of the diagnosis “lumbar
syndrome”. The results of the WBV study
demonstrating an increase in degeneration
of the lumbar spine at a threshold vibration
exposure value of A(8) = 0.63 m/s² have
been confirmed. With respect to the duration
of exposure, a clear increase in risk is observed
after very long periods of exposure.
