Affiliations: Department of Kinesiology, University of Waterloo,
Waterloo, Ontario, Canada | Institute of Work and Health, Toronto, Ontario,
Canada | Department of Public Health Sciences, University of
Toronto, Toronto, Ontario, Canada | Centre of Research Expertise for the Prevention of
Musculoskeletal Disorders (CRE-MSD), Ontario, Canada
Note: [] Address for correspondence: Richard Wells, Department of
Kinesiology, University of Waterloo, 200 University Avenue, W., Waterloo,
Ontario, Canada, N2L 3G1. Tel.: +1 519 888 4567 ext 33069; Fax: +1 519 746
6776; E-mail: wells@uwaterloo.ca
Abstract: Interventions to prevent musculoskeletal disorders by reducing
mechanical exposures may range from equipment adjustments, through changing
workstations and equipment or implementing administrative controls, to the
design and redesign of work processes. Although generally positive, the
literature reports mixed results for the effects of such workplace
interventions on musculoskeletal disorders. We propose that an important factor
which influences these results is the change intensity. This construct
includes: the body part(s) affected, the size of exposure magnitude reduction
in the particular task or tasks involved in the change, the time fraction of
the job to which the change applies, the coverage of the change (proportion of
the workforce affected), and the adherence (if applicable) by the workforce to
the change. The intensities of changes recently completed as part of a
participatory ergonomics research program were characterized using this
approach. Intensity scores were estimated based upon these parameters for peak
and cumulative mechanical exposures. Changes affecting a production system
re-design and re-configuration were judged to have medium to high intensity,
while most other changes were judged to be of small intensity. Comparisons are
made to the intensity of changes determined from reports in the published
literature. Factors which maximize intensity as well as potential barriers to
achieving higher intensities are described.
Keywords: Ergonomic intervention, musculoskeletal disorders, exposure, production system, participatory ergonomics, prevention and control
