(Sources : R. Op De Beeck, F. Willems, J.P. Demaret, F. Gavray, Ergonomie, Cursustekst bij de opleiding Adviseur Ergonomie van Prevent, Prevent, 2009, Op De Beeck, V. Hermans, Research on work-related low back disorders, European Agency for Safety and Health at Work, Luxembourg, 2000)
(Bronnen : R. Op De Beeck, F. Willems, J.P. Demaret, F. Gavray, Ergonomie, Cursustekst bij de opleiding Adviseur Ergonomie van Prevent, Prevent, 2009, R. Op De Beeck, V. Hermans, Research on work-related low back disorders, European Agency for Safety and Health at Work, Luxembourg, 2000)