Biomechanics Commons^™

Fusion Et Validation De Modèles Musculosquelettiques De La Colonne Lombaire Pour La Prévention Et La Réadaptation Des Travailleurs, Christian Larivière, Farshid Ghezelbash, Amir Eskandari, Denis Gagnon, Hakim Mecheri, Navid Arjmand, Aboulfazl Shirazi-Adl

Rapports de recherche scientifique

Les charges imposées sur la colonne vertébrale lombaire constituent un facteur de risque important pour les maux de dos. Connaître la distribution de ces forces internes lors d’activités de travail est nécessaire autant en prévention qu’en réadaptation des travailleurs. La modélisation musculosquelettique (MS) de la colonne vertébrale est la seule approche non invasive permettant d’estimer les charges sur les structures internes de la colonne.

Deux modèles ont été développés au Québec, soient un modèle par éléments finis (MEF) guidé par le mouvement et un autre guidé par des mesures électromyographiques (EMG) d’activation musculaire (modèle MEMG). Ces modèles sont donc sensibles …

Validation Of An Emg Submaximal Method To Calibrate A Novel Dynamic Emg-Driven Musculoskeletal Model Of The Trunk: Effects On Model Estimates, Amir H. Eskandari, Farshid Ghezelbash, Aboulfazl Shirazi-Adl, Denis Gagnon, Hakim Mecheri, Christian Larivière

Études primaires

Background

Multijoint EMG-assisted optimization models are reliable tools to predict muscle forces as they account for inter- and intra-individual variations in activation. However, the conventional method of normalizing EMG signals using maximum voluntary contractions (MVCs) is problematic and introduces major limitations. The sub-maximal voluntary contraction (SVC) approaches have been proposed as a remedy, but their performance against the MVC approach needs further validation particularly during dynamic tasks.

Methods

To compare model outcomes between MVC and SVC approaches, nineteen healthy subjects performed a dynamic lifting task with two loading conditions.

Results

Results demonstrated that these two approaches produced highly correlated results …

Mise Au Point Et Validation D’Une Approche Terrain De Prédiction Des Chargements Au Dos Basée Sur Des Données De Laboratoire, Alain Delisle, François Thénault, André Plamondon, Hakim Mecheri

Rapports de recherche scientifique

Les troubles musculosquelettiques (TMS) et particulièrement ceux au bas du dos affectent de nombreux travailleuses et travailleurs chaque année au Québec (Vézina et al., 2011). Le chargement mécanique au bas dos est reconnu comme un facteur de risque pouvant mener au développement de maux de dos, et la manutention de charges peut occasionner des chargements importants et répétés. La façon habituelle de quantifier le chargement au dos des individus est d’estimer le moment qui s’exerce à l’articulation lombo-sacrée (L5/S1). L’estimation de ce moment se fait généralement en laboratoire et nécessite la connaissance de la position et de l’orientation de …

Analyse Du Concept De Marge De Manœuvre En Ergonomie Du Point De Vue Du Contrôle De La Motricité Humaine, Philippe Corbeil, André Plamondon, Denys Denis

Rapports de recherche scientifique

Le concept de marge de manœuvre se définit comme la liberté dont dispose un travailleur pour élaborer différentes façons de travailler afin de répondre aux exigences de production, et ce, sans effet défavorable sur sa santé (Coutarel, Caroly, Vézina et Daniellou, 2015; St-Vincent et al., 2011). Une forte charge de travail jumelée à une faible latitude décisionnelle restreint l’élaboration des gestes et pourrait pénaliser ainsi la santé des opérateurs. Les connaissances actuelles des façons de faire des manutentionnaires, qu’ils soient experts ou non, ne nous permettent pas d’apprécier dans sa totalité l’ampleur de cette liberté lorsqu’un individu doit répéter …

Submaximal Electromyography-Driven Musculoskeletal Modeling Of The Human Trunk During Static Tasks: Equilibrium And Stability Analyses, Farshid Ghezelbash, Aboulfazl Shirazi-Adl, Denis Gagnon, Ali Shahvarpour, Navid Arjmand, Amir Hossein Eskandari, Christian Larivière

Études primaires

Conventional electromyography-driven (EMG) musculoskeletal models are calibrated during maximum voluntary contraction (MVC) tasks, but individuals with low back pain cannot perform unbiased MVCs. To address this issue, EMG-driven models can be calibrated in submaximal tasks. However, the effects of maximal (when data points include the maximum contraction) and submaximal calibration techniques on model outputs (e.g., muscle forces, spinal loads) remain yet unknown. We calibrated a subject-specific EMG-driven model, using maximal/submaximal isometric contractions, and simulated different independent tasks. Both approaches satisfactorily predicted external moments (Pearson’s correlation ∼ 0.75; relative error = 44%), and removing calibration tasks under axial torques markedly improved …

Evaluating Stability Of Human Spine In Static Tasks: A Combined In Vivo-Computational Study, Farshid Ghezelbash, Ali Shahvarpour, Christian Larivière, Aboulfazl Shirazi-Adl

Études primaires

Various interpretations and parameters have been proposed to assess spinal stability such as antagonist muscle coactivity, trunk stiffness and spinal buckling load; however, the correlation between these parameters remains unknown. We evaluated spinal stability during different tasks while changing the external moment and load height and investigated likely relationships between different EMG- and model-based parameters (e.g., EMG coactivity ratio, trunk stiffness, force coactivity ratio) and stability margins. EMG and kinematics of 40 young healthy subjects were recorded during various quasi-static tasks. Muscle forces, trunk stiffness and stability margins were calculated by a nonlinear subject-specific EMG-assisted-optimization musculoskeletal model of the trunk. …

Développement D’Un Outil Personnalisé D’Aide À La Décision En Vue De Minimiser Les Risques En Manutention Impliquant Des Postures Symétriques Et Asymétriques, Aboulfazl Shirazi-Adl, Navid Arjmand, André Plamondon

Rapports de recherche scientifique

Les charges excessives imposées sur la colonne vertébrale lombaire constituent un facteur de risques important pour les maux de dos. La modélisation biomécanique de la colonne vertébrale est la seule approche non invasive permettant d’estimer ces charges, mais la complexité de ces modèles limite leur utilisation par des ergonomes. Pour aider ces derniers à identifier des situations à risque de blessures au dos afin de limiter le chargement aux structures lombaires, il existe des outils d’aide à la décision comme l’équation de levage du NIOSH (Revised NIOSH Lifting Equation, Waters et al., 1993) ainsi que les tables …

Développement, Validation Et Application D’Une Méthode Quantitative Pour Évaluer Les Déplacements Des Pieds Des Manutentionnaires, André Plamondon, Antoine Muller, Xavier Robert-Lachaîne, Jasmin Vallée-Marcotte, Denys Denis, Christian Larue, Hakim Mecheri, Philippe Corbeil

Rapports de recherche scientifique

Les troubles musculosquelettiques lors d’activités de manutention manuelle (MM) sont encore très présents dans nos milieux de travail. Les facteurs de risque biomécanique les plus souvent associés aux douleurs au dos incluent la manutention manuelle, les répétitions excessives, les torsions du tronc et les levers de charges lourdes. Plusieurs déterminants d’une tâche de MM ont été étudiés pour déterminer leur importance sur l'exposition physique des travailleurs. Par exemple, la hauteur de la charge, la distance initiale de la charge par rapport au corps, la masse soulevée et la vitesse du soulèvement sont tous des déterminants liés à la …

Combined Influence Of Transfer Distance, Pace, Handled Mass And Box Height On Spine Loading And Posture, Xavier Robert-Lachaine, Philippe Corbeil, Antoine Muller, Jasmin Vallée-Marcotte, Hakim Mecheri, Denys Denis, André Plamondon

Études primaires

Work-related low back disorders are commonly associated with handling tasks. The objective of this study was to determine the combined influence of distance, pace, handled mass and height, on back loading and posture during free box transfer. Kinematics and kinetics of 17 handlers were recorded during a box transfer task between two pallets. Four-way repeated measures ANOVA were conducted on four lift-deposit height conditions (from lift and deposit of 0.16 or 1.16 m), three distances between pallets (1.5, 1.0 and 0.5 m), two handled masses (10 and 20 kg) and two paces (free and faster). The interaction between distance and …

The Effect Of Extensible And Non-Extensible Lumbosacral Orthoses On Anticipatory Postural Adjustments In Participants With Low Back Pain And Healthy Controls, Christian Larivière, Richard Preuss

Études primaires

Background

Wearing a lumbosacral orthosis (LSO) is known to influence spine mechanics, but less is known about how LSOs affect motor control. Whether the use of a LSO can negatively affect motor control of the lumbar spine is still under debate.

Objective

The current study examined the immediate effects of two flexible LSOs (extensible and non-extensible) on the anticipatory postural adjustments that prepare the spine for a predictable perturbation.

Design

A comparative study using a repeated measures design in a laboratory setting.

Methods

Healthy controls (n = 20) and participants with low back pain (n = 40) performed a rapid …

Validation D’Un Nouveau Système De Mesure Inertiel Pour Estimer La Cinématique Du Corps Humain : Le Cas Des Manutentionnaires, Hakim Mecheri, Xavier Robert-Lachaîne, Antoine Muller, Christian Larue, André Plamondon

Rapports de recherche scientifique

Les études terrain avec des systèmes ambulatoires capables de mesurer la cinématique du corps humain sont maintenant possibles. Toutefois, ces systèmes de mesure sont souvent très onéreux, ce qui pourrait empêcher les entreprises ou encore les intervenants de se les procurer. L’objectif de cette recherche était de valider un nouveau système ambulatoire abordable (Perception Neuron Noitom de moins de 2 000 $ CA) pour mesurer la cinématique complète du corps humain et fournir une rétroaction fidèle de la tâche réalisée en utilisant ici l’exemple du travail de manutentionnaires.

Pour ce faire, cinq sujets ont été recrutés et des mesures …

Subject-Specific Regression Equations To Estimate Lower Spinal Loads During Symmetric And Asymmetric Static Lifting, F. Ghezelbash, A. Shirazi-Adl, Z. El Ouaaid, A. Plamondon, N. Arjmand

Études primaires

Workplace safety assessment, personalized treatment design and back pain prevention programs require accurate subject-specific estimation of spinal loads. Since no noninvasive method can directly estimate spinal loads, easy-to-use regression equations that are constructed based on the results of complex musculoskeletal models appear as viable alternatives. Thus, we aim to develop subject-specific regression equations of L4-L5 and L5-S1 shear and compression forces during various symmetric/asymmetric tasks using a nonlinear personalized finite element musculoskeletal trunk model. Kinematics and electromyography (EMG) activities of 19 young healthy subjects were collected during 64 different symmetric/asymmetric tasks. To investigate the reliability and accuracy of the musculoskeletal …

Validation Of A Low-Cost Inertial Motion Capture System For Whole-Body Motion Analysis, X. Robert-Lachaine, H. Mecheri, A. Muller, C. Larue, A. Plamondon

Études primaires

While some low-cost inertial motion capture (IMC) systems are now commercially available, generally, they have not been evaluated against gold standard optical motion capture (OMC). The objective was to validate the low-cost Neuron IMC system with OMC. Whole-body kinematics were recorded on five healthy subjects during manual handling of boxes for about 32 min while wearing 17 magnetic and inertial measurement units with Optotrak clusters serving as a reference. The kinematical model was calibrated anatomically for OMC and with poses for IMC. Local coordinate systems were aligned with angular velocities to dissociate differences due to technology or kinematical model. Descriptive …

Feasibility Of Quantifying The Physical Exposure Of Materials Handlers In The Workplace With Magnetic And Inertial Measurement Units, Xavier Robert-Lachaine, Christian Larue, Denys Denis, Alain Delisle, Hakim Mecheri, Philippe Corbeil, André Plamondon

Études primaires

Handling tasks can expose workers to risk factors. The objective was to describe the feasibility of using magnetic and inertial measurement units (MIMUs) to quantify the physical exposure of materials handlers in the workplace. Full-body kinematics were obtained with MIMUs on 10 handlers gathering products ordered by retailers with a pallet truck. An observer classified the visual difference (VD) of segment orientation between a MIMUs avatar and video recordings in three categories (none, minor and major) for each product transfer. The feet, arms, shoulders and head were considered similar for ≥97% of observations. The trunk segment obtained the most differences …

Vers Une Stratégie Intégrée De Prévention En Manutention : Document De Sensibilisation À La Prévention Des Troubles Musculosquelettiques (Tms) Reliés À Des Tâches De Manutention, Denys Denis, Edith Vinet

Guides

Destiné à tous les intervenants et les milieux de travail préoccupés par la prévention des troubles musculosquelettiques (TMS) reliés à des tâches de manutention, ce document propose une stratégie intégrée de prévention en manutention.

Combinant formation et intervention, cette stratégie repose sur la compréhension, l’observation et l’analyse de cinq principes d’action. Ces principes d’action sont les points communs de l’ensemble des techniques de manutention qu’utilisent les travailleurs. Chacun d’eux possède des repères d’observation caractéristiques. Les repères indiquent ainsi les compromis que le travailleur doit faire pour atteindre son objectif de préserver sa santé et sa sécurité, puisqu’ils sont liés aux …

A Comparison Of Lumbar Spine And Muscle Loading Between Male And Female Workers During Box Transfers, Denis Gagnon, André Plamondon, Christian Larivière

Études primaires

There is a clear relationship between lumbar spine loading and back musculoskeletal disorders in manual materials handling. The incidence of back disorders is greater in women than men, and for similar work demands females are functioning closer to their physiological limit. It is crucial to study loading on the spine musculoskeletal system with actual handlers, including females, to better understand the risk of back disorders. Extrapolation from biomechanical studies conducted on unexperienced subjects (mainly males) might not be applicable to actual female workers. For male workers, expertise changes the lumbar spine flexion, passive spine resistance, and active/passive muscle forces. However, …

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: …

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 …

Effects Of Sex, Age, Body Height And Body Weight On Spinal Loads: Sensitivity Analyses In A Subject-Specific Trunk Musculoskeletal Model, F. Ghezelbash, A. Shirazi-Adl, N. Arjmand, Z. El-Ouaaid, A. Plamondon, J. R. Meakin

Études primaires

Subject-specific parameters influence spinal loads and the risk of back disorders but their relative effects are not well understood. The objective of this study is to investigate the effects of changes in age (35–60 years), sex (male, female), body height (BH: 150–190 cm) and body weight (BW: 50–120 kg) on spinal loads in a full-factorial simulation using a personalized (spine kinematics, geometry, musculature and passive properties) kinematics driven musculoskeletal trunk finite element model. Segmental weight distribution (magnitude and location along the trunk) was estimated by a novel technique to accurately represent obesity. Five symmetric sagittal loading conditions were considered, and …