title: Influence of snow shovel shaft configuration on lumbosacral biomechanics during a load-lifting task.
abstract: Lower-back injury from snow shovelling may be related to excessive joint loading. Bent-shaft snow shovels are commonly available for purchase; however, their influence on lower back-joint loading is currently not known. Therefore, the purpose of this study was to compare L5/S1 extension angular impulses between a bent-shaft and a standard straight-shaft snow shovel. Eight healthy subjects participated in this study. Each completed a simulated snow-lifting task in a biomechanics laboratory with each shovel design. A standard motion analysis procedure was used to determine L5/S1 angular impulses during each trial, as well as peak L5/S1 extension moments and peak upper body flexion angle. Paired-samples t-tests (α = 0.05) were used to compare variables between shovel designs. Correlation was used to determine the relationship between peak flexion and peak moments. Results of this study show that the bent-shaft snow shovel reduced L5/S1 extension angular impulses by 16.5% (p = 0.022), decreased peak moments by 11.8% (p = 0.044), and peak flexion by 13.0% (p = 0.002) compared to the straight-shaft shovel. Peak L5/S1 extension moment magnitude was correlated with peak upper body flexion angle (r = 0.70). Based on these results, it is concluded that the bent-shaft snow shovel can likely reduce lower-back joint loading during snow shovelling, and thus may have a role in snow shovelling injury prevention.
authors.affiliation: School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada; Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4, Canada; Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada. Electronic address: lewinson@ucalgary.ca.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Lewinson
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Rouhi
authors.forename: D Gordon E
authors.initials: DG
authors.lastname: Robertson
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004867:Equipment Design; D006804:Ergonomics; D005260:Female; D006801:Humans; D017770:Lifting; D008159:Lumbar Vertebrae; D008297:Male; D009068:Movement; D012447:Sacrum; D012914:Snow; D016474:Weight-Bearing / Q000502:physiology*; D021801:Zygapophyseal Joint / Q000502:physiology*
keywords: Ergonomics; Joint loading; L5/S1; Low back pain; Spine