Development and laboratory evaluation of a markerless method to estimate low back intersegmental moments in
Diana Pardo Ramos1, Léan Mazier-Vallet2, Adriana Savescu3
1Univ Lyon, Univ Gustave Eiffel, Univ Claude Bernard Lyon 1, LBMC UMR T_9406, F‑69622 Lyon, France; Conseil Départemental du Val de Marne, Direction des Crèches, 94000 Créteil, France.
Abstract:
In early childhood care settings, the frequent adoption of awkward postures and repetitive manual material handling tasks are biomechanical risk factors for the development of musculoskeletal disorders. Estimating low back intersegmental moments under realistic conditions could help identify such risks. Realistic conditions make measurement challenging, particularly in achieving a balance between unobtrusive instrumentation and acceptable accuracy. The aim of this study was to develop and evaluate a markerless method for estimating low back intersegmental moments for childcare-related activities. In standardized laboratory conditions, eight participants performed six manual material handling and sit-to-stand tasks, representative of real work situations, using two different baby dummies weighting 2.7 kg and 10 kg. The proposed method, only based on video recordings, was evaluated by comparison with a reference approach combining marker-based motion capture and force platforms. Mean absolute differences in L5/S1 joint moment estimation between both approaches were approximately 20 Nm, which is comparable to errors reported in the literature for methods without force platforms that can be deployed in situ. By requiring no instrumentation or participant preparation, this method offers a practical solution for quantifying low back intersegmental moments.
