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 …

Effect Of Personalized Spinal Profile On Its Biomechanical Response In An Emg-Assisted Optimization Musculoskeletal Model Of The Trunk, C. Larivière, A.H. Eskandari, H. M., F. Ghezelbash, D. Gagnon, A. Shirazi-Adl

Études primaires

Recent developments in musculoskeletal (MS) modeling have been geared towards model customization. Personalization of the spine profile could affect estimates of spinal loading and stability, particularly in the upright standing posture where large inter-subject variations in the lumbar lordosis have been reported. This study investigates the biomechanical consequences of changes in the spinal profile. In 31 participants (healthy and with back pain), (1) the spine external profile was measured, (2) submaximal contractions were recorded in a dynamometer to calibrate the EMG-driven MS model and finally (3) static lifting in the upright standing challenging spine stability while altering load position and …

Comparative Evaluation Of Different Spinal Stability Metrics, Amir Hossein Eskandari, Farshid Ghezelbash, Aboulfazl Shirazi-Adl, Christian Larivière

Études primaires

Direct in vivo measurements of spinal stability are not possible, leaving computational estimations (such as dynamic time series and structural analyses) as the feasible option. However, differences between different stability assessment approaches and metrics remain unclear. To explore this, we asked 32 participants to perform 35 cycles of repetitive lifts with and without load (4/2.6 kg for males/females). EMG signals and 3D kinematics were collected via 12 surface electrodes and 17 inertial sensors, and three dynamical stability measures were computed: short and long temporal and conventional maximum Lyapunov exponents (LyE) and maximum Floquet multipliers (FM). A dynamic subject-specific EMG-assisted musculoskeletal …

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 …

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 …

New Taxonomy For Assessing Manual Material Handlers’ Footstep Patterns, Jasmin Vallée-Marcotte, Antoine Muller, Xavier Robert-Lachaine, Véronique Fecteau, Denys Denis, André Plamondon, Philippe Corbeil

Études primaires

Current taxonomies for assessing foot strategies in manual material handling lack exhaustive classification of foot movements and foot positioning. They also fail to consider different instants of the task as checkpoints to relate foot strategies. The goal of the study was first to develop a new taxonomy to assess foot positions and motions considering those limitations. The second goal was to assess reliability and reproducibility using raw agreement percentages, Cohen's kappa, prevalence-adjusted, bias-adjusted kappa and Gwet's AC1. A filmed task consisted of transferring boxes from one pallet to another. Intra- and inter-rater reliability were assessed reviewing 23% and 10%, respectively, …

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 …

Effet De L’Expertise Et Du Sexe Sur Les Contraintes À L’Épaule En Manutention, Etienne Goubault, Romain Martinez, Najoua Assila, Jennifer Dowling-Medley, Élodie Monga-Dubreuil, Sophie-Anne Scherrer, André Plamondon, Mickaël Begon

Rapports de recherche scientifique

L’atteinte de troubles musculosquelettiques (TMS) parmi les travailleurs et travailleuses au Québec était récemment estimée à 732 000 cas (Stock et al., 2014). Ces TMS sont associés aux activités professionnelles impliquant des efforts physiques prolongés, intenses et/ou répétitifs, telles que des tâches d’assemblage, de manutention, d’aide à la personne ou encore de maintien de posture prolongée sur un poste de travail. Les membres supérieurs, qui représentaient 30,1 % des cas de TMS déclarés et acceptés au Québec de 1998 à 2007 (Michel et al., 2010), sont les plus touchés après le dos. Plus particulièrement, l’épaule figure comme l’articulation …

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 …

Revisiting The Effect Of Manipulating Lumbar Stability With Load Magnitudes And Positions: The Effect Of Sex On Trunk Muscle Activation, Christian Larivière, Ali Shahvarpour, Christina Gravel, Myriam Gauvin, Anne-Marie Jean, Ariane Viau, Hakim Mecheri

Études primaires

Background

Lumbar spine stability is regularly studied by positioning different loads at different heights and distance and measuring trunk muscle activation changes. Some of these studies have reported sex differences, but this needs to be revisited while controlling for confounding factors.

Method

20 males and 20 females sustained three static standing postures, with various loads (0, 5 and 10% of body weight), to evaluate the effect of height and distance. Activation of 12 trunk muscles was recorded with surface electromyography (EMG).

Results

Females activated their external obliques a little more than males, with increases ranging between 1.5 and 2.3% of …

Trunk Postural Balance And Low Back Pain: Reliability And Relationship With Clinical Changes Following A Lumbar Stabilization Exercise Program, Ali Shahvarpour, Dany H. Gagnon, Richard Preuss, Sharon M. Henry, Christian Larivière

Études primaires

Lumbar stabilization programs reduce pain and disability, but the mechanisms of action underlying this treatment are unknown. Trunk postural control during unstable sitting represents a surrogate measure of motor control mechanisms involved to maintain the dynamic stability of the spine. This exploratory study aimed to determine the reliability of trunk postural control measures over an 8-week interval, their sensitivity to low back pain status and treatment and their relationship with clinical outcomes. Trunk postural control measures were determined in patients with low back pain before and after an 8-week lumbar stabilization exercise program. Healthy controls were assessed over the same …

The Effect Of Wearing A Lumbar Belt On Biomechanical And Psychological Outcomes Related To Maximal Flexion-Extension Motion And Manual Material Handling, Ali Shahvarpour, Richard Preuss, Michael J.L. Sullivan, Alessia Negrini, Christian Larivière

Études primaires

Workers with low back pain (LBP) may benefit from wearing a lumbar belt (LB), but the biomechanical and psychological mechanisms involved are not fully understood. Two types of flexible LB (extensible and non-extensible) were compared to a control condition (no LB) regarding pain-related (pain, fear of pain and catastrophizing) and biomechanical (range of motion – ROM) outcomes related to two tasks: maximal trunk flexion-extension and manual material handling. Healthy controls and participants with LBP were tested. During both tasks, the two LBs reduced the lumbar ROM in participants with LBP in the same way as healthy controls. This was observed …

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 …

Validation Of Inertial Measurement Units With An Optoelectronic System For Whole-Body Motion Analysis, Xavier Robert-Lachaine, Hakim Mecheri, Christian Larue, André Plamondon

Études primaires

The potential of inertial measurement units (IMUs) for ergonomics applications appears promising. However, previous IMUs validation studies have been incomplete regarding aspects of joints analysed, complexity of movements and duration of trials. The objective was to determine the technological error and biomechanical model differences between IMUs and an optoelectronic system and evaluate the effect of task complexity and duration. Whole-body kinematics from 12 participants was recorded simultaneously with a full-body Xsens system where an Optotrak cluster was fixed on every IMU. Short functional movements and long manual material handling tasks were performed and joint angles were compared between the two …

Obesity And Obesity Shape Markedly Influence Spine Biomechanics: A Subject-Specific Risk Assessment Model, Farshid Ghezelbash, Aboulfazl Shirazi-Adl, André Plamondon, Navid Arjmand, Mohammad Parnianpour

Études primaires

Underlying mechanisms of obesity-related back pain remain unexplored. Thus, we aim to determine the effect of obesity and its shapes on the spinal loads and the associated risks of injury. Obesity shapes were initially constructed by principal component analysis based on datasets on 5852 obese individuals. Spinal loads, cycles to vertebral failure and trunk stability margin were estimated in a subject-specific trunk model taking account of personalized musculature, passive ligamentous spine, obesity shapes, segmental weights, spine kinematics and bone mineral density. Three obesity shapes (mean and extreme abdominal circumferences) at three body weights (BWs) of 86, 98 and 109 kg …

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 …