1Ergonomics Technology Center, University of Connecticut Health Center, U.S.A.
2Institute for Microstructural Sciences National Research Council, Ottawa, Canada
3University Hospital Department of Biomedical Engineering and Informatics, Umeä, Sweden
4National Institute of Working Life Department of Work and the Physical Environment, Umeä, Sweden
5Department of Occupational and Environmental Medicine, Sundsvall, Hospital, Sundsvall, Sweden
6Department of Physics Finnish Institute of Occupational Health, Helsinki, Finland