1. a Team Innovation and Ergonomics , TNO Work and Employment , PO Box 718, Hoofddorp, 2130 AS, The Netherlands
2. b Team Innovation and Ergonomics , TNO Work and Employment , PO Box 718, Hoofddorp, 2130 AS, The Netherlands E-mail:
3. c Dept of Assembly Engineering , TNO Industrial Technology , PO Box 6235, Eindhoven, 5600 HE, The Netherlands