title: Relative importance of expertise, lifting height and weight lifted on posture and lumbar external loading during a transfer task in manual material handling.
abstract: The objective of this study was to measure the effect size of three important factors in manual material handling, namely expertise, lifting height and weight lifted. The effect of expertise was evaluated by contrasting 15 expert and 15 novice handlers, the effect of the weight lifted with a 15-kg box and a 23-kg box and the effect of lifting height with two different box heights: ground level and a 32 cm height. The task consisted of transferring a series of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables (moments) while expertise had low impact. On the other hand, expertise showed a significant effect of posture variables on the lumbar spine and knees. All three factors are important, but for a reduction of external back loading, the focus should be on the lifting height and weight lifted.
  The objective was to measure the effect size of three important factors in a transfer of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables but expertise was a major determinant in back posture.
authors.affiliation: Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montréal, Québec, Canada, H3A 3C2. Plamondon.andre@irsst.qc.ca
authors.forename: André
authors.initials: A
authors.lastname: Plamondon
authors.forename: Christian
authors.initials: C
authors.lastname: Larivière
authors.forename: Alain
authors.initials: A
authors.lastname: Delisle
authors.forename: Denys
authors.initials: D
authors.lastname: Denis
authors.forename: Denis
authors.initials: D
authors.lastname: Gagnon
mesh_terms: D000328:Adult; D019567:Back Injuries / Q000209:etiology / Q000517:prevention & control*; D001696:Biomechanical Phenomena; D006801:Humans; D017770:Lifting; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D011187:Posture / Q000502:physiology*; D011361:Professional Competence; D013647:Task Performance and Analysis; D014741:Video Recording; D016474:Weight-Bearing / Q000502:physiology*