Ergonomics Commons^™

Effects Of Motion Segment Simulation And Joint Positioning On Spinal Loads In Trunk Musculoskeletal Models, F. Ghezelbash, A. H. Eskandari, A. Shirazi-Adl, N. Arjmand, Z. El Ouaaid, A. Plamondon

Études primaires

Musculoskeletal models represent spinal motion segments by spherical joints/beams with linear/nonlinear properties placed at various locations. We investigated the fidelity of these simplified models (i.e., spherical joints with/without rotational springs and beams considering nonlinear/linear properties) in predicting kinematics of the ligamentous spine in comparison with a detailed finite element (FE) model while considering various anterior-posterior joint placements. Using the simplified models with different joint offsets in a subject-specific musculoskeletal model, we computed local spinal forces during forward flexion and compared results with intradiscal pressure measurements. In comparison to the detailed FE model, linearized beam and spherical joint models failed to …

Accuracy And Repeatability Of Single-Pose Calibration Of Inertial Measurement Units For Whole-Body Motion Analysis, Xavier Robert-Lachaine, Hakim Mecheri, Christian Larue, André Plamondon

Études primaires

Portable inertial measurement units (IMUs) are suitable for motion analysis outside the laboratory. However, IMUs depend on the calibration of each body segment to measure human movement. Different calibration approaches have been developed for simplicity of use or similarity to laboratory motion analysis, but they have not been extensively examined. The main objective of the study was to determine the accuracy and repeatability of two common single-pose calibrations (N-pose and T-pose) under different conditions of placement (self-placement and passive placement), as well as their similarity to laboratory analysis based on anatomical landmarks. A further aim of the study was to …

Difference Between Male And Female Workers Lifting The Same Relative Load When Palletizing Boxes, André Plamondon, Christian Larivière, Denys Denis, Hakim Mecheri, Iuliana Nastasia

Études primaires

A few biomechanical studies have contrasted the work techniques of female and male workers during manual material handling (MMH). A recent study showed that female workers differed from males mostly in the strategy they used to lift 15-kg boxes from the ground, especially regarding task duration, knee and back postures and interjoint coordination. However, the lifting technique difference observed in females compared to males was perhaps due to a strength differences. The objective of this study was to test whether female workers would repeat the same lifting technique with a load adjusted to their overall strength (females: 10 kg; males: …

Effect Of Local Magnetic Field Disturbances On Inertial Measurement Units Accuracy, Xavier Robert-Lachaine, Hakim Mecheri, Christian Larue, André Plamondon

Études primaires

Inertial measurement units (IMUs), a practical motion analysis technology for field acquisition, have magnetometers to improve segment orientation estimation. However, sensitivity to magnetic disturbances can affect their accuracy. The objective of this study was to determine the joint angles accuracy of IMUs under different timing of magnetic disturbances of various durations and to evaluate a few correction methods. Kinematics from 12 individuals were obtained simultaneously with an Xsens system where an Optotrak cluster acting as the reference system was affixed to each IMU. A handling task was executed under normal laboratory conditions and imposed magnetic disturbances. Joint angle RMSE was …

A Biomechanical Comparison Between Expert And Novice Manual Materials Handlers Using A Multi-Joint Emg-Assisted Optimization Musculoskeletal Model Of The Lumbar Spine, Denis Gagnon, André Plamondon, Christian Larivière

Études primaires

Expertise is a key factor modulating the risk of low back disorders (LBD). Through years of practice in the workplace, the typical expert acquires high level specific skills and maintains a clean record of work-related injuries. Ergonomic observations of manual materials handling (MMH) tasks show that expert techniques differ from those of novices, leading to the idea that expert techniques are safer. Biomechanical studies of MMH tasks performed by experts/novices report mixed results for kinematic/kinetic variables, evoking potential internal effect of expertise. In the context of series of box transfers simulated by actual workers, detailed internal loads predicted by a …

Subject-Specific Biomechanics Of Trunk: Musculoskeletal Scaling, Internal Loads And Intradiscal Pressure Estimation, F. Ghezelbash, A. Shirazi-Adl, N. Arjmand, Z. El-Ouaaid, A. Plamondon

Études primaires

Development of a subject-specific computational musculoskeletal trunk model (accounting for age, sex, body weight and body height), estimation of muscle forces and internal loads as well as subsequent validation by comparison with measured intradiscal pressure in various lifting tasks are novel, important and challenging. The objective of the present study is twofold. First, it aims to update and personalize the passive and active structures in an existing musculoskeletal kinematics-driven finite element model. The scaling scheme used an existing imaging database and biomechanical principles to adjust muscle geometries/cross-sectional-areas and passive joint geometry/properties in accordance with subjects’ sex, age, body weight and …

Abatteuses Forestières : Dispositif Et Circuits De Commande Relatifs À La Sécurité, Laurent Giraud, Yuvin Chinniah, Damien Burlet-Vienney, Joseph-Jean Paques, Marina Koutchouk, Renaud Daigle

Rapports de recherche scientifique

Les abatteuses forestières sont des engins tout-terrains conçus pour évoluer en forêt, qui servent de véhicule moteur pour déplacer une tête d’abattage.

L’utilisation d’abatteuses avec une tête d’abattage multifonctionnelle s’est largement répandue au Québec ces dernières années pour deux raisons :

• Cette méthode d’abattage réduit la machinerie car une seule machine tronçonne et façonne les arbres en billots, là où il en fallait plusieurs avec les anciennes méthodes;
• La méthode d’abattage abîme moins le sol de la forêt car le façonnage des arbres se fait sur place et crée ainsi un tapis végétal.

L’IRSST a lancé une série d’études sur …

Accidents Types Des Monteurs De Lignes Du Secteur De La Construction (Annexe), Évelyne Kedl, Lucie Laflamme, Lyne Marinacci

Rapports de recherche scientifique

La première phase du projet dont il est ici question vise à résumer, en un nombre limité d’accidents types, les circonstances dans lesquelles les monteurs de lignes se blessent le plus souvent et les caractéristiques les plus courantes de leurs lésions. À cette fin, les fichiers "pairés" d’accidents des trois entrepreneurs participants et de la CESST ont servi à décrire 236 accidents en utilisant un total de 15 variables. Le traitement de ces données, rétrospectives, a conduit à la reconstruction de six classes d’accidents différentes les unes des autres.

Ces classes se distinguent d’abord par le genre de l’accident. Nos …

Accidents Types Des Monteurs De Lignes Du Secteur De La Construction, Évelyne Kedl, Lucie Laflamme, Lyne Marinacci

Rapports de recherche scientifique

La première phase du projet dont il est ici question vise à résumer, en un nombre limité d’accidents types, les circonstances dans lesquelles les monteurs de lignes se blessent le plus souvent et les caractéristiques les plus courantes de leurs lésions. À cette fin, les fichiers "pairés" d’accidents des trois entrepreneurs participants et de la CESST ont servi à décrire 236 accidents en utilisant un total de 15 variables. Le traitement de ces données, rétrospectives, a conduit à la reconstruction de six classes d’accidents différentes les unes des autres.

Ces classes se distinguent d’abord par le genre de l’accident. Nos …