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Performance acoustique des alarmes de recul tonales et large bande en milieu ouvert en vue d’une utilisation optimale
Ce rapport fait état de travaux portant sur l'audibilité et la localisation auditive des deux grands types d'alarmes de recul (tonale [« bip-bip »] et à large bande de fréquences [« pshit-pshit »]), le fonctionnement des alarmes à niveau autoajustable et l'effet du positionnement des alarmes sur la distribution sonore à l'arrière des véhicules, en vue de favoriser une utilisation optimale de ces dispositifs et de minimiser les risques d'accidents liés au recul des véhicules. Les deux...
Risque vibratoire chez les opérateurs d’engins mobiles
Cartographie des postures et des vibrations au poste de conduite Les opérateurs d'engins mobiles sont exposés à des vibrations de l'ensemble du corps susceptibles d'être à l'origine de troubles du rachis. La procédure actuelle d'évaluation du risque vibratoire ne tient pas compte de la position et des mouvements du corps des conducteurs. Ces paramètres sont aujourd'hui considérés comme des cofacteurs importants. Pour cette raison, l'INRS mène des travaux de recherche visant à mettre au...
Association Between Farm Machinery Operation and Low Back Disorder in Farmers
A Retrospective Cohort Study Objective: The association between whole body vibration (WBV) as measured by annual accumulated use of all-terrain vehicles (ATV)/combine/tractor operation and low back disorders (LBDs) among farmers was investigated. Methods: Saskatchewan Farm Injury Cohort Study data was used. Baseline data were collected in 2007 on the three vehicle types and other factors. Follow-up data on LBD symptoms were collected during 2013 resulting in 1149 samples. Results: Adjusted for age, education, and gender, LBDs were associated with tractor operation for 1 to 150 hours/year (Relative...
Whole body vibration exposures in bus drivers: A comparison between a high-floor coach and a low-floor city bus
Low back pain (LBP) is common in occupational bus drivers and studies have shown a dose–response relationship between whole body vibration (WBV) exposure and LBP. Bus design may be an important factor in determining the WBV exposure a bus driver receives. The purpose of this study was to determine whether differences exist in WBV exposures between two buses commonly used in long urban commuter routes: a high-floor coach and a low-floor city bus. Each bus was driven over a standardized test route which included four road types: a newer smooth freeway, a rougher old freeway, a city street segment...
Identification of quality attributes of automotive idle sounds and whole-body vibrations
The aims of this study are the generation and comparison of the semantic spaces of vehicle idling sounds and vibrations and the determination of their quality dimensions. In this study, two different sets of quality attributes were developed for idling sounds (34 attributes) and whole-body vibrations (22 attributes). In contrast to prior investigations, the results demonstrated that the sound level alone is an insufficient attribute for describing the complexity of idle sounds and vibration perceptions. The qualities of both idle sounds and idle vibrations have multidimensional, complex characters...
Sécurité des travailleurs derrière les véhicules lourds - Évaluation de trois types d'alarmes sonores de recul
Plusieurs accidents graves impliquant des véhicules en marche arrière sont enregistrés chaque année. Il est donc primordial d’assurer la conception optimale des signaux avertisseurs de recul afin d’alerter les travailleurs et de les aider à localiser le véhicule en marche arrière, tout en limitant la gêne due au bruit. Les avertisseurs sonores présentent un avantage sur les avertisseurs visuels puisqu’ils captent habituellement l’attention des individus. Toutefois, des accidents peuvent survenir dans des environnements...
Vibration and mechanical shock exposure strongly associated with prevalence of neck pain
The objective of this study was to determine whether whole-body vibration (WBV) and mechanical shock exposure from quad bike use are associated with the prevalence of neck and low back pain (LBP) in New Zealand farmers and rural workers. Physical exposures (mechanical shocks), employee status, and low levels of workplace satisfaction are all significantly associated with the 12-month prevalence of LBP in this rural workforce that regularly uses quad bikes. Both vibration and mechanical shock exposure were strongly associated with 12-month prevalence of neck pain. The 7-day prevalence of neck pain...
Driving : The effects of WBV on cerebral oxygenation oscillations and the development of central fatigue
The objective of this study was to assess the effects of WBV on cerebral oxygenation oscillations of the pre-frontal cortex region in healthy men based on the wavelet transform of near-infrared spectroscopy (NIRS) signals. . This study demonstrates that WBV at 4.5 Hz induce highest cerebral oscillation responses. The enhancement of the cerebral spontaneous oscillation activity indicates an activation of the pre-frontal cortex region and an increased demand for oxygen. At prolonged regional neuronal activity due to vibration exposure, energy demand might exceed energy supply, and an imbalance might...
Exploring how anthropometric, vehicle and workplace factors influence whole-body vibration exposures during on-farm use of a quad bike
The primary aim of this study is to determine whether a combination of body height, terrain and vehicle mechanical factors confound for the effect of body mass on WBV exposure while using a quad bike under normal rural working conditions. A seat pad mounted triaxial accelerometer and data logger recorded full work day vibration and shock data from 130 New Zealand rural workers. Personal, vehicle and workplace characteristics were gathered using a modified version of the Whole Body Vibration Health Surveillance Questionnaire. Whole-body vibrations were analysed in accordance with the ISO 2631-1...
Reducing whole-body vibration exposure in backhoe loaders by education of operators
Whole-body vibration is a health hazard for operators of construction machinery. The level of whole-body vibration exposure on the operator is governed by three different factors; performance of the suspension system of the machine, planning of the work and the skills of the operator.In this research work it is investigated whether there is a potential in bringing down the level of whole-body vibration exposure by educating operators of backhoe loaders. This is carried out by an experimental setup. Six experienced operators participated in the experiments carried out on two different sizes of backhoe...
Optimisation of whole body vibration analysis for suspended cabin tractor semitrailer
This work has been conducted to find out the health risk associated with suspended cabin tractor semi-trailer driving work. Suspended cabin tractor semi-trailer drivers are exposed to whole body vibration (WBV) during their work. Some drivers suffer from low back pain caused by vibration. The practical significance of applying suspended cabin type of tractor semi-trailer was tested at different road conditions, different speeds as well as different load conditions for comfortable driver seat interface (x, y, z axes) and the ride comfort parameters have been prioritised using Taguchi's L27 orthogonal...
Vibrations, exiguïté, faible marge de manoeuvre
Comment améliorer le poste de conduite du métro de Montréal? Ce document est destiné aux intervenants en santé et en sécurité du travail, aux ergonomes, aux ingénieurs et à toute personne concernée par l'amélioration d'un poste de travail dans un contexte de faible marge de manoeuvre. Il décrit sommairement tant la démarche technique que la collaboration qui ont permis d'améliorer le poste de conduite du métro de Montréal dont le siège, l'espace restreint et les...
Évaluation de l'exposition aux vibrations globales du corps chez les opérateurs de compacteurs de sol
L'exécution de travaux routiers et de compactage de sols se fait généralement à l'aide de compacteurs vibrants monocylindres (à rouleau compresseur). Or, ces engins exposent les opérateurs à des niveaux de vibrations globales du corps élevés, reconnues comme un facteur de risque du développement de lombalgies. Seules quelques études européennes ont jusqu'ici caractérisé leurs vibrations, lesquelles dépassent parfois la limite maximale d'exposition quotidienne. Cette activité...
Whole body- vibration (WBV) levels remained just above ISO 2631-1 after being optimized for load-haul-dump (LHD) vehicles
Operators of load-haul-dump (LHD) vehicles are commonly exposed to wholebody- vibration (WBV) levels above ISO 2631-1 and EU Directive 2002/44/EC guidelines. Vibration exposure was lowest when the LHD was driven at the lowest speed, forward, over smooth terrain, with ride control on and the bucket loaded (0.20 m/s 2 ). The A(8) decreased from 0.84 m/s 2 when driving with ride control off, over mixed terrain using all gears, to 0.53 m/s 2 when driving with ride control on and an optimized seat. The estimated daily exposure decreased but remained just above the ISO 2631-1 and EU Directive 2002/44...
Whole-body vibration : Typical postures of the drivers result in enhanced spinal forces compared with the upright sitting posture
Typically drivers of container-bridge cranes are forced to sit with a forward bent upper trunk to control the position and motion of the container. Fork-lift truck drivers incline the upper trunk to the side to look forward or they twist to one side during reversing. The forces transmitted in the lumbar spine were assessed by means of a biomechanical model. Under realistic vibration stress the bent postures result in an increase of the compressive and the shear forces. The increase of the spine forces is the result of the increased muscle forces stabilizing the inclined trunk. On container bridge...
Damper with optimised progressive damping characteristic is better at shock mitigation than suspended commercial seat as presently available
A single degree-of-freedom simulation model of a seat equipped with a non-linear fore-and-aft suspension system was developed. The performance of a typical fore-and-aft suspension system was analysed using typical vibration and shock acceleration signals measured in loaders while travelling on off-road terrain and while driving the bucket into a heap of soil. The simulations are of use to seat manufacturers in developing improved fore-and-aft seat suspension for wheel loaders. Source: Study of simultaneous shock and vibration control by a fore-and-aft suspension system of a driver’s seat...
Study recommandations to greatly reduce the transmission of vertical vibration to the operator.
Vibratory soil compactors are articulated vehicles designed to achieve efficient compaction of the soil and road base-layers through a vibratory drum/roller integrating an unbalanced rotating mass. The low frequency whole-body vibration are directly transmitted to the operator through the driver seat, which in the vast majority of the vehicles employed in Québec is limited to a polyurethane foam cushion. The results of this study suggest that the seat and the cabin mounts amplify the low frequency vibration for all the vehicles considered but this amplification is limited for the 13-ton...
Whole body vibration as a potential cause of Parkinson’s disease
In the largest case-control study of Parkinson's disease conducted in Canada to date, Parkinson’s disease showed u-shaped pattern of risk for whole body vibration : increased risk among those with no exposure, and among those with exposure, increasing risk with increasing intensity of exposure. Among those with exposure, there were increasing odds of Parkinson’s disease with increasing intensity of exposure and with increasing censoring of exposure in the years prior to diagnosis. The odds ratio was statistically significant in the second highest intensity category, for exposures...
Driving an unloaded bucket resulted in significantly higher levels of vibration exposure than with a loaded bucket.
Although it is not possible to conclude that high levels of WBV exposure were the only cause of the reported neck and back discomfort, vibration levels experienced by the underground mining load-haul-dump ( LHD) operators indicated health risks were likely to develop, with a higher probability of injury to the back. Analysis of all operators’ injury profiles and their vibration profiles will be important in future studies in order to determine whether these variables are related. The mining industry will need to consider a number of different intervention strategies to have an impact on injury...
A postwoman delivering mail using a low-powered motorcycle was diagnosed with bilateral Raynaud's phenomenon.
This case report presents the hypothesis that the effect of HAV may result not in a single disorder, but in multiple disorders. Although occupational epidemiological studies do not usually address comorbidity, it is not uncommon for exposure to produce multiple effects (e.g. an association between HAV and tendonitis has been reported) . Comorbidity due to occupational exposure therefore needs further epidemiological investigation. For 15 years the woman had driven a two-stroke 50 cc motorcycle to deliver mail and was exposed to hand-arm vibration for 4 h/day. Before delivering the mail, she had...
Surveys suggest that transport workers are more exposed to vibrations than the average working population.
European workers in transport over land and through pipelines seem also to be more exposed to vibrations from tools and machinery than the average working population. Several studies demonstrate the detrimental consequences of sustained sitting and being exposed to whole body vibration: exposure to vibrations may lead to back disorders. Based on the information available on heavy machines, the significance of the seat is important when steps to reduce full-body vibrations are taken. Full body vibration, for example caused by the driver’s cabin, may also affect the vision, coordination and...
Le niveau vibratoire et sonore des équipements miniers n'est pas considéré lorsque vient le temps de choisir le matériel
Dans cette étude, plusieurs recommandations visant à réduire l’exposition des travailleurs miniers au bruit et aux vibrations sont formulées. Un total de 28 équipements miniers répartis dans 8 mines souterraines québécoises a été évalué. Pour les vibrations globales du corps, les équipements à risque élevé (pour une exposition quotidienne de 8 heures) sont les rétrocaveuses (sur rails et sur roues), l’opération d’une foreuse à béquille sur...
Le risque « vibrations » est mal connu dans plusieurs entreprises
La métrologie de terrain complète les informations sur les performances annoncées par les constructeurs d'engins et permet d'initier un plan de prévention. Des études ergonomiques et épidémiologiques d'entreprises utilisant des chariots automoteurs et des engins de chantier montrent qu'il est possible de réduire l'apparition de pathologies, en agissant sur la durée de la conduite, le réglage du siège, le mode de travail ou l'état du sol. Source : Vibrations, chariots automoteurs et engins...
Une étude de l’INRS passe les transpalettes au crible
Le niveau vibratoire élevé auquel les conducteurs de transpalettes électriques sont soumis impose la mise en place d’actions de prévention. Tel est le constat de l’INRS à la suite d’une étude de comportement de 6 TEP (transpalettes électriques à conducteur porté). L es conducteurs de charriots sont plus souvent que les autres salariés soumis à des risques de lombalgies et autres mots de dos, de sciatiques, de radiculalgies crurales, de microtraumatismes de la colonne vertébrale… L’étude...
Effects of vibration at workplaces
Characteristic values of hand-arm and whole-body vibration The effects of vibration when working with handheld and hand-guided devices (Hand-Arm Vibration – HAV) and when driving mobile work machines and vehicles (Whole-Body Vibrations – WBV) can endanger the health and safety of employees. Damage to bones and joints and circulatory problems in the hand and arm systems as well as disc damage to the spine as a result of the effects of vibrations are recognised occupational diseases. Since the entry into force of the EC Vibration Protection Directive 2002/44/ EC in 2002 there has been...
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