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Acceptation des exosquelettes par les opérateurs : étude exploratoire
L'introduction des exosquelettes, comme toute nouvelle technologie, constitue un changement au niveau de l'organisation et de l'activité des opérateurs. C'est dans ce cadre qu'est abordée la question spécifique de l'acceptabilité et de l'acceptation de ces dispositifs par les opérateurs. Pour cela, un questionnaire a été élaboré et administré à des utilisateurs, anciens utilisateurs et nonutilisateurs d'exosquelettes. En termes de santé et sécurité, les résultats...
A comparison of lumbar spine and muscle loading between male and female workers during box transfers
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...
Two-dimensional biomechanical thumb model for pipetting
Manual pipetting imposes repetitive movements, high force, and awkward postures on the thumb, fingers, and wrist, increasing the risk of musculoskeletal injuries. The purpose of this study is to provide a linear regression model to estimate the optimal pipetting grip height based on the two-dimensional biomechanical static thumb model developed in this study. This biomechanical static thumb model uses hand anatomy and static equilibrium conditions to estimate internal tendon forces against a given external force. Based on the model, we conclude that the optimal grip height is 3 cm in males and...
The influence of external load configuration on trunk biomechanics and spinal loading during sudden loading
Sudden loading is a major risk factor for work-related lower back injuries among occupations involving manual material handling (MMH). The current study explored the effects of external weight configuration on trunk biomechanics and trunk rotational stiffness in the sagittal plane during sudden loading. Fifteen asymptomatic volunteers experienced sudden loadings using the same magnitude of weight (9 kg) with two different configurations (medially- or laterally-distributed) at three levels of height (low, middle and high). Results of this study showed that the medially distributed weight...
Occupational biomechanical risk factors for surgically treated ulnar nerve entrapment in a prospective study of male construction workers
Evidence was provided for forceful hand-grip work, with and without vibration, as a risk factor for ulnar nerve entrapment (UNE) surgery in a large cohort of Swedish construction workers. Several individual biomechanical factors comprising such work were associated with increased risk of UNE, including: increased grip force, upper extremity load, frequency of hand-held tool use, and hand arm vibration. Source: Jackson, J. A., Olsson, D., Punnett, L., Burdorf, A., Järvholm, B. et Wahlström, J. (2018). Scandinavian journal of work, environment & health . http://dx.doi.org/10.5271/sjweh...
Surface electromyography for risk assessment in work activities designed using the “revised NIOSH lifting equation”
The aims of this study were: to identify surface electromyography (sEMG)-based indices of trunk muscles acquired during the execution of lifting tasks designed using the revised NIOSH lifting equation and featuring a progressively increasing lifting index (LI); to study changes of these indices in relation to the LI; to evaluate the relationship between the identified indices and forces (FL5−S1) and moments (ML5−S1) at the L5-S1 joint. sEMG, kinematic and kinetic data of 20 male workers were recorded in three conditions. We computed the average rectified value (ARV), root mean square...
How does the biomechanical exposure of the upper body in manual box handling differ from exposure in other tasks in the real industrial context?
The assessment of biomechanical exposure during handling tasks in relation to other activities that are performed in industrial settings can be crucial to understand the biomechanical demands of manual box handling for the upper limbs. This study aims to evaluate the representativeness of the handling task to the upper body in comparison with the other tasks in a real setting, compare the biomechanical exposure between tasks, and identify the differences in exposure during manual box handling from job exposure. Twelve workers had biomechanical exposure assessed through trapezius muscle activity...
Effectiveness of a vacuum lifting system in reducing spinal load during airline baggage handling
Information on spinal loading for using lift assist systems for airport baggage handling is lacking. We conducted a laboratory study to evaluate a vacuum lift system for reducing lumbar spinal loads during baggage loading/unloading tasks. Ten subjects performed the tasks using the industry average baggage weight of 14.5?kg on a typical two-shelved baggage cart with or without using the lift system (i.e. lifting technique). Repeated measures analysis of variance (2 tasks × 2 shelf heights x 2 techniques) was used. Spinal loads were estimated by an electromyography-driven biomechanical model...
Effects of work surface and task difficulty on neck-shoulder posture and trapezius activity during a simulated mouse task
Objectives. The purpose of this study is to evaluate the influence of the work surface and task difficulty on the head, upper back and upper arm postures and activity of the descending trapezius during a simulated mouse task. Methods. Healthy female university students (N = 15) were evaluated. The work surface was positioned at elbow height (EH) and above elbow height (AEH) and the task difficulty was set at low (LD) and high (HD) levels. The postures were recorded by inclinometers. Trapezius activity was normalized by the maximum voluntary isometric contraction (MVIC). Results. Significantly...
A detailed description of the short-term musculoskeletal and cognitive effects of prolonged standing for office computer work
Due to concerns about excessive sedentary exposure for office workers, alternate work positions such as standing are being trialled. However, prolonged standing may have health and productivity impacts, which this study assessed. Twenty adult participants undertook two hours of laboratory-based standing computer work to investigate changes in discomfort and cognitive function, along with muscle fatigue, movement, lower limb swelling and mental state. Over time, discomfort increased in all body areas (total body IRR [95% confidence interval]: 1.47[1.36–1.59]). Sustained attention reaction...
Développement d’un système de mesures et d’un protocole de mesures permettant de quantifier l’exposition physique des manutentionnaires
L'objectif principal de ce projet était de combiner différents senseurs et instruments pour expérimenter, en laboratoire et sur le terrain, un système de mesures permettant d'estimer quantitativement l'exposition physique des manutentionnaires. Ce type de système pourrait éventuellement servir à évaluer objectivement l'efficacité d'approches de prévention. Un second objectif consistait à mettre au point une stratégie d'échantillonnage pour optimiser la mesure de l'exposition physique...
Inter-day reliability of surface electromyography recordings of the lumbar part of erector spinae longissimus and trapezius descendens during box lifting
Background: Low back pain and neck-shoulder pain are the most reported types of work-related musculoskeletal disorders, and performing heavy lifting at work and working with trunk rotation increase the risk of developing work-related musculoskeletal disorders. Surface electromyography (sEMG) provides information about the electrical activity of muscles. Thus it has the potential to retrieve indirect information about the physical exposure of specific muscles of workers during their actual work. This study aimed to investigate the inter-day reliability of absolute and normalized amplitude of sEMG...
Proceedings of the 5th International Digital Human Modeling Symposium
The proceedings present the the peer-reviewed articles of the 5th International Digital Human Modeling Symposium. The symposium was held from June 26-28, 2017 at the Fraunhofer-Institute for Communication, Information Processing and Ergonomics (FKIE), in cooperation with the unit "Human factors and ergonomics" of the Federal Institute for Occupational Safety and Health (BAuA). Source: https://www.baua.de/EN/Service/Publications/Report/Gd91.html
NIOSH Lifting Equation App: NLE Calc
The National Institute for Occupational Safety and Health (NIOSH) Lifting Equation mobile application, NLE Calc, is a tool to calculate the overall risk index for single and multiple manual lifting tasks. This application provides risk estimates to help evaluate lifting tasks and reduce the incidence of low back injuries in workers. Source: https://www.cdc.gov/niosh/topics/ergonomics/nlecalc.html
Cumulative occupational mechanical exposures during working life and risk of sickness absence and disability pension
Prospective cohort study Using a biomechanical job exposure matrix combined with Danish registers, cumulative occupational mechanical exposures throughout life (ie, more years with heavy and frequent lifting, and kneeling work) predicted risk of long-term sickness absence among older workers. Importantly, heavy lifting throughout working life was associated with disability pension. Source: Sundstrup E, Hansen ÅM, Mortensen EL, Poulsen OM, Clausen T, Rugulies R, Møller A, Andersen LL. (2017). Scand J Work Environ Health . http://dx.doi.org/10.5271/sjweh.3663
Work-related biomechanical exposure and job strain in midlife separately and jointly predict disability after 28 years
A Finnish longitudinal study Higher level of work-related biomechanical exposure and job strain in midlife separately and jointly carried a higher risk for increase in disability after 28 years. Mitigation of both of these co-occurring exposures at work in midlife could reduce the risk of disability in later life. Thus the workplace should be promoted as an arena for preventive interventions regarding disability in old age. Source: Prakash KC, Neupane S, Leino-Arjas P, von Bonsdorff MB, Rantanen T, von Bonsdorff ME, Seitsamo J, Ilmarinen J, Nygård C-H. (2017). Scand J Work Environ Health...
Qualitative ergonomics/human factors research in health care
Current state and future directions The objective of this systematic review was to understand the current state of Ergonomics/Human Factors (E/HF) qualitative research in health care and to draw implications for future efforts. This systematic review identified 98 qualitative research papers published between January 2005 and August 2015 in the seven journals endorsed by the International Ergonomics Association with an impact factor over 1.0. The majority of the studies were conducted in hospitals and outpatient clinics, were focused on the work of formal health care professionals, and were classified...
9e Conférence scientifique internationale sur la prévention des troubles musculosquelettiques (PREMUS) - 2016
Réunissant près de 400 participants, 360 communications orales et 60 posters, PREMUS, la 9e Conférence scientifique internationale sur la prévention des troubles musculosquelettiques (TMS) a permis d'échanger sur les recherches actuelles et les pratiques d'interventions sur ce sujet. Plusieurs thèmes ont notamment été abordés : travail sédentaire, travail en posture debout, biomécanique des membres supérieurs lors de l'utilisation des nouvelles technologies de communication, prise en compte du sexe/genre...
Difference between male and female workers lifting the same relative load when palletizing boxes
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...
Evaluating the low back biomechanics of three different office workstations: Seated, standing, and perching
The objective of this study was to evaluate how different workstations may influence physical behavior in office work through motion and how that may affect spinal loads and discomfort. Twenty subjects performed a typing task in three different workstations (seated, standing, and perching) for one hour each. Measures of postural transitions, spinal loads, discomfort, and task performance were assessed in order to understand the effects of workstation interaction over time. Results indicated that standing had the most amount of motion (6–8 shifts/min), followed by perching (3–7 shifts...
Estimation of lumbar spinal loading and trunk muscle forces during asymmetric lifting tasks
Application of whole-body musculoskeletal modelling in OpenSim Large spinal compressive force combined with axial torsional shear force during asymmetric lifting tasks is highly associated with lower back injury (LBI). The aim of this study was to estimate lumbar spinal loading and muscle forces during symmetric lifting (SL) and asymmetric lifting (AL) tasks using a whole-body musculoskeletal modelling approach. Thirteen healthy males lifted loads of 7 and 12 kg under two lifting conditions (SL and AL). Kinematic data and ground reaction force data were collected and then processed by a whole-body...
Estimation du chargement au dos
Développement d'une méthode ambulatoire intégrant la cinématique du dos et de l'électromyographie De nombreux travailleurs1 sont atteints de maux de dos chaque année. La région lombaire est de loin celle qui est la plus fréquemment atteinte, et ce type de troubles musculosquelettiques est principalement occasionné par des efforts excessifs, surtout en soulevant quelque chose, et les chargements aux tissus de la colonne qu'ils engendrent. Il n'existe pas de méthode de mesure directe de ces chargements qui puisse...
Patterns of biomechanical demands are associated with musculoskeletal pain in the beginning of professional life
A population-based study Objectives: This study aimed to describe patterns of occupational biomechanical demands in the beginning of professional life and to quantify their association with the presence and intensity of regional musculoskeletal pain. Methods :Cross-sectional data from 21-year-old participants were collected during the third wave of the EPITeen cohort study (N=1733, 37.5% were workers). Ten different work-related biomechanical tasks were characterized. Latent class analysis was conducted to identify empirical patterns of occupational biomechanical demands. The presence and intensity...
Estimation du chargement lombaire au moyen de modèles biomécaniques articulaires
Évaluation et application Les troubles musculosquelettiques (TMS) et tout particulièrement les affections vertébrales constituent un fardeau autant pour la société que pour les personnes qui en sont affectées. Au Québec, le nombre d'affections vertébrales s'établissait en 2011 à 21 228 et elles représentaient près de 30 % de l'ensemble des lésions professionnelles indemnisées. C'est la région lombaire de la colonne vertébrale qui est la zone la plus touchée (60...
Effect of firefighters' personal protective equipment on gait
The biomechanical experiment with eight male and four female firefighters demonstrates that the effect of adding essential equipment: turnout ensemble, self-contained breathing apparatus, and boots (leather and rubber boots), significantly restricts foot pronation. This finding is supported by a decrease in anterior-posterior and medial-lateral excursion of center of plantar pressure (COP) trajectory during walking. The accumulation of this equipment decreases COP velocity and increases foot-ground contact time and stride time, indicating increased gait instability. An increase in the flexing resistance...
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