Distal upper limb disorders and ergonomics of VDU work: a review of the epidemiological evidence

A review is presented of epidemiological peer-reviewed publications that relate the mechanical exposure of the arm in work with visual display units (VDU) to musculoskeletal disorders of the upper limb. The twenty included studies were divided into those with (1-7) and without (8-21) use of physical examination in the definition of cases. The main conclusion of this review is the documentation of evidence for the VDU work per se, none or insufficient lower arm support and non-neutral positions of the wrist as predictors of distal upper limb disorders (DULDs). These findings are based solely on studies that use physical examination or objective signs to define the DULDs, and the conclusions are not changed after inclusion of studies based only on self-reported symptoms. When the last category of studies is included as documentation in the review, the amount of VDU work (and an exposuredose/ effect relationship) will also be documented as predictors. The referred studies indicated that not only the VDU work per se, but also (and in particular) VDU work for more than 20 hours per week combined with limited opportunity for rest breaks and without lower arm support is a predictor of DULDs. Another conclusion is that critical reviews may benefit from use of both strict criteria and less strict criteria for inclusion of studies, to optimize the conclusions drawn from existing documentation.