L'impact des exigences de qualité sur le développement de la polyvalence et sur l'apprentissage
Une grande entreprise du secteur de l'aéronautique désire développer la polyvalence de ses assembleurs-monteurs par l'instauration de la rotation de postes. Convenant qu'il s'agit d'une problématique complexe, l'expertise de l'Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) est sollicitée. La demande formulée consiste à identifier les conditions requises pour implanter la rotation des postes, souhaitant ainsi prévenir les TMS qui affectent cette population de travailleurs. Le département où sont assemblés les cabines de pilotage de deux des avions-phares de l'entreprise est ciblé à la fois de par les exigences physiques qui le caractérisent, sa position stratégique dans le cycle de production optimisée (lean production) et le haut niveau d'expertise requis pour y effectuer les tâches d'assemblage. On y retrouve quatre stations d'assemblage dans lesquelles se répartissent plus d'une vingtaine d'assembleurs sous la supervision de trois chefs d'équipe. Le travail se caractérise entre autres par des cycles longs – puisque l'assemblage complet d'une cabine s'échelonne sur plusieurs jours – et par des exigences élevées de qualité.
This study analysed the work ability of elderly construction workers. Forty male construction workers, 20 young (age < 33 yrs) and 20 senior (age>44 yrs) workers, were tested regarding aerobic power (VO2max) and muscle strength. The aerobic demand of a number of tasks in construction work was measured and compared with the workers' aerobic power. VO2max was higher for the young, and they performed better on most muscle strength tests. The measurements showed that about half of the senior workers had to use more than 30% of their maximum oxygen uptake on some tasks. In conclusion, because elderly construction workers decline in physical fitness, they are more exposed to overload when performing heavy manual work than are their younger peers. Increasing their individual fitness or adjusting their workload may be important for staying in the workforce for such workers.
Source: Jebens E, Mamen A, Medbø JI, Knudsen O, Veiersted KB. Ergonomics, 2014.
Quelques contributions récentes
Ce numéro spécial est dédié aux travaux récents des membres du groupe Ergonomics analysis of work and training (EAWT) qui se réunit périodiquement, depuis 1991, dans le cadre du Congrès de l'Association internationale d'ergonomie (IEA). Les six contributions présentées ici découlent du dernier congrès tenu à Recife en 2012 et des collaborations subséquentes entre des chercheurs de plusieurs pays. Vous pourrez découvrir les particularités de l'approche ergonomique des questions de formation ainsi que la diversité de ses apports. Ces travaux offrent l'occasion de réfléchir aux conceptions de la formation et à leurs liens avec l'activité de travail et avec les conditions de travail et d'apprentissage. Ils permettent aussi de prendre connaissance des cadres conceptuels et méthodologiques variés qui alimentent aujourd'hui ce domaine de recherche.
Source: Pistes, 2014, vol. 16, no 4.
A randomized controlled trial
BACKGROUND: Hospital workers with physically demanding jobs are at risk for developing recurrent LBP. There is a lack of studies evaluating multidisciplinary prevention of low back pain (LBP) in hospital workers.
OBJECTIVE: This randomized controlled trial evaluates the effect of a multidisciplinary prevention program, focusing on a client-centred approach, on hospital workers at risk for developing LBP.
METHODS: Caregiving hospital workers were allocated to an experimental (12-week lasting multidisciplinary prevention program) or control group (no intervention). They were evaluated prior to the intervention and after a 6 months follow-up period. Primary outcome measures included incidence of LBP, work absenteeism and general health. Secondary outcomes included daily physical activity, job satisfaction and coping strategies.
RESULTS: A significant improvement was seen for passive coping after 6 months follow-up, but no significant differences were observed between groups in primary or other secondary outcome measures (p> 0.05).
CONCLUSIONS: A multidisciplinary prevention program fitting into a bio-psychosocial context may not have been intensive enough to promote a change in daily habitudes, and had no effect on work absenteeism, incidence of LBP or general health. Further research should determine whether prevention of LBP is possible in caregiving personnel.
Source: Roussel, Nathalie, Kos, Daphne, Demeure, Isaline, Heyman, Annette, De Clerck, Marleen, Zinzen, Evert, Struyf, Filip, Nijs, Jo. (2014). Journal of Back and Musculoskeletal Rehabilitation.
The goal of this study was to evaluate the effect of different types of computer pointing devices and placements on posture and muscle activity of the hand and arm. A repeated measures laboratory study with 12 adults (6 females, 6 males) was conducted. Participants completed two mouse-intensive tasks while using a conventional mouse, a trackball, a stand-alone touchpad, and a rollermouse. A motion analysis system and an electromyography system monitored right upper extremity postures and muscle activity, respectively. The rollermouse condition was associated with a more neutral hand posture (lower inter-fingertip spread and greater finger flexion) along with significantly lower forearm extensor muscle activity. The touchpad and rollermouse, which were centrally located, were associated with significantly more neutral shoulder postures, reduced ulnar deviation, and lower forearm extensor muscle activities than other types of pointing devices. Users reported the most difficulty using the trackball and touchpad. Rollermouse was not more difficult to use than any other devices. These results show that computer pointing device design and location elicit significantly different postures and forearm muscle activities during use, especially for the hand posture metrics.
Source: Lin, Michael Y.C., Young, Justin G., & Dennerlein, Jack T. (2015). Applied Ergonomics, 47, 259-264.
Les poids lourds sont rarement équipés de série d'outils et d'équipements permettant de réduire la pénibilité du travail du conducteur. Ces équipements optionnels sont mal connus des acheteurs de nouveaux véhicules alors qu'ils présentent un réel bénéfice pour le conducteur lors de la conduite, lors des manoeuvres, et lors de la manutention des charges. Cette brochure a pour objectif de présenter les équipements et les outils participant à la réduction de la pénibilité du travail des conducteurs routiers de poids lourds de plus de 3,5 tonnes, et leurs avantages dans la réduction des accidents du travail et maladies professionnelles dont ils sont victimes. L'ensemble des équipements présentés peuvent être acquis à la commande du véhicule ou installés en 2e monte.
If you haven't purchased your 20 pound Thanksgiving turkey or your 10 pound bag of potatoes rest assured employees at your local grocery stores are busy restocking the shelves each day with your favorite Thanksgiving foods. It‘s hard enough lifting those items into your cart but what about the workers who haul those tons of turkeys, pounds of potatoes, and stock the shelves with green beans, cranberries, and stuffing? Nearly 2.5 million cashiers and stocking clerks are at risk for musculoskeletal injuries that stem from overexertion in grocery stores. According to Liberty Mutual Research Institute, overexertion is the leading cause of workplace injuries and account for $14.2 billion in direct costs. In the grocery sector, overexertion injuries that lead to soft tissue injuries, A.K.A. musculoskeletal disorders, account for 41% of the injuries and lost work in grocery stores.
In order to safely and effectively extinguish fires and rescue life, firefighters are required to routinely wear self-contained breathing apparatus (SCBA), yet little is known about the specific physiological and psychological demands associated with repeated exposure to tasks that require SCBA. A total of 12 experienced firefighters took part in a series of commonly encountered SCBA activities: free search, guideline search and live firefighting tasks under room temperature (∼20°C) and extreme heat (∼180°C) conditions to assess changes in heart rate, blood pressure, mood, perceived workload and air usage. Findings demonstrate that live firefighting is associated with greater perceived exhaustion than free search or guideline exercises; however, all tasks lead to high cardiovascular demand regardless of the presence of heat. No significant impact of task upon mood and no significant differences between the perceived demands of guideline, free search and live firefighting exercises were found.
Source: Young PM, Gibson AS, Partington E, Partington S, Wetherell MA. Ergonomics, 2014.
Objectives :Musculoskeletal disorders (MSD) are a major cause of pain, disability, and costs. Prevention of MSD at work is frequently described in terms of implementing an ergonomics program, often a participatory ergonomics (PE) program. Most other workplace injury prevention activities take place under the umbrella of a formal or informal occupational health and safety management system (OHSMS). This study assesses the similarities and differences between OHSMS and PE as such knowledge could help improve MSD prevention activities.
Methods: Using the internationally recognized Occupational Health and Safety Assessment Series (OHSAS 18001), 21 OHSMS elements were extracted. In order to define PE operationally, we identified the 20 most frequently cited papers on PE and extracted content relevant to each of the OHSAS 18001 elements.
Results: The PE literature provided a substantial amount of detail on five elements: (i) hazard identification, risk assessment and determining controls; (ii) resources, roles, responsibility, accountability, and authority; (iii) competence, training and awareness; (iv) participation and consultation; and (v) performance measurement and monitoring. However, of the 21 OHSAS elements, the PE literature was silent on 8 and provided few details on 8 others.
Conclusions: The PE literature did not speak to many elements described in OHSMS and even when it did, the language used was often different. This may negatively affect the effectiveness and sustainability of PE initiatives within organizations. It is expected that paying attention to the approaches and language used in management system frameworks could make prevention of MSD activities more effective and sustainable.
Source: Yazdani A, Neumann P, Imbeau D, Bigelow P, Pagell M, Theberge N, Hilbrecht M, Wells R. Scand J Work Environ Health, 2014.
Triple-blind, randomized placebo-controlled trial
Topical menthol gels are classified "topical analgesics" and are claimed to relieve minor aches and pains of the musculoskeletal system. In this study we investigate the acute effect of topical menthol on carpal tunnel syndrome (CTS). We screened 645 slaughterhouse workers and recruited 10 participants with CTS and chronic pain of the arm/hand who were randomly distributed into two groups to receive topical menthol (Biofreeze) or placebo (gel with a menthol scent) during the working day and 48 hours later the other treatment (crossover design). Participants rated arm/hand pain intensity during the last hour of work (scale 0-10) immediately before 1, 2, and 3 hours after application. Furthermore, global rating of change (GROC) in arm/hand pain was assessed 3 hours after application. Compared with placebo, pain intensity and GROC improved more following application of topical menthol (P = 0.026 and P = 0.044, resp.). Pain intensity of the arm/hand decreased by -1.2 (CI 95%: -1.7 to -0.6) following topical menthol compared with placebo, corresponding to a moderate effect size of 0.63. In conclusion, topical menthol acutely reduces pain intensity during the working day in slaughterhouse workers with CTS and should be considered as an effective nonsystemic alternative to regular analgesics in the workplace management of chronic and neuropathic pain.
Source: Sundstrup E, Jakobsen MD, Brandt M, et al. Rehabilitation Research and Practice, 2014.
Objective: Work-related musculoskeletal disorders (MSDs) are the leading cause of work disability in the developed economies. The objective of this study was to describe trends in the incidence of MSDs attributed to work exposures in Ontario over the period 2004–2011.
Methods: An observational study of work-related morbidity obtained from three independent sources for a complete population of approximately six million occupationally active adults aged 15–64 in the largest Canadian province. We implemented a conceptually concordant case definition for work-related non-traumatic MSDs in three population-based data sources: emergency department encounter records, lost-time workers' compensation claims and representative samples of Ontario workers participating in consecutive waves of a national health interview survey.
Results: Over the 8-year observation period, the annual per cent change (APC) in the incidence of work-related MSDs was −3.4% (95% CI −4.9% to −1.9%) in emergency departments' administrative records, −7.2% (−8.5% to −5.8%) in lost-time workers' compensation claims and −5.3% (−7.2% to −3.5%) among participants in the national health interview survey. Corresponding APC measures for all other work-related conditions were −5.4% (−6.6% to −4.2%), −6.0% (−6.7% to −5.3%) and −5.3% (−7.8% to −2.8%), respectively. Incidence rate declines were substantial in the economic recession following the 2008 global financial crisis.
Conclusions: The three independent population-based data sources used in this study documented an important reduction in the incidence of work-related morbidity attributed to non-traumatic MSDs. The results of this study are consistent with an interpretation that the burden of non-traumatic MSDs arising from work exposures is declining among working-age adults.
Source: Cameron A Mustard, Andrea Chambers, Selahadin Ibrahim, Jacob Etches, Peter Smith. Occup Environ Med, 2014.
Objectives: Physical exposures (eg, lifting or bending) are believed to be risk factors for low-back pain (LBP), but the literature is inconsistent. Exposure and LBP prevalence differ considerably between occupations, and exposure–outcome associations could be severely modified by the presence of particular occupational groups. We aimed to investigate the influence of such outlying groups on the properties of associations between exposure and LBP.
Methods: Lifting and trunk flexion were observed for 371 of 1131 workers within 19 groups. LBP was obtained from all workers during three follow-up years. Both exposure variables were associated with LBP (P<0.01) in this parent dataset. By removing the 19 groups one-by-one and performing logistic regressions analysis on the 18 remaining groups, we demonstrated that one group, mainly road workers, with outlying exposures and LBP prevalence substantially affected the exposure–outcome association in the total population. In order to further examine this phenomenon, we assessed, by simulation, the influence of realistic sizes (n=4, 8, 16, 32, 64, 128), mean exposures (e=2000, 3000, 4000 lifts and e=30, 40, 50% trunk flexion time) and LBP prevalences (p=70, 80, 90, 100%) of the outlying group on the strength and certainty of the eventual relationship between exposure and LBP. For each combination of n, e and p, 3000 virtual studies were constructed, including the simulated group together with the other 18 original groups from the parent data-set. Average odds ratios (OR), 95% confidence limits, and power (P<0.05) were calculated across these 3000 studies as measures of the properties of each virtual study design.
Results: OR were attenuated more towards 1 and power decreased with smaller values of n, e, and p in the outlying group. Changes in group size and prevalence had a larger influence on OR and power than changes in mean exposure.
Conclusions: The size and characteristics of a single group with high exposure and outcome prevalence can strongly influence both the OR point estimate and the likelihood of obtaining significant exposure–outcome associations in studies of large populations. These findings can guide interpretations of prior epidemiological studies and support informed design of future studies.
Source: Coenen P, Mathiassen SE, Kingma I, Boot CRL, Bongers PM, van Dieën JH. 2014, Scand J Work Environ Health.
Objective: The aim of this study was to evaluate the prevalence of upper-body-quadrant pain among ultrasonographers and to evaluate the association between individual ergonomics, musculoskeletal disorders, and occurrence of neck pain.
Method: A hundred and ten (N = 110) Belgian and Dutch male and female hospital ultrasonographers were consecutively enrolled in the study. Data on work-related ergonomic and musculoskeletal disorders were collected with an electronic inquiry, including questions regarding ergonomics (position of the screen, high-low table, and ergonomic chair), symptoms (neck pain, upper-limb pain), and work-related factors (consecutive working hours a day, average working hours a week).
Results: Subjects with the screen on their left had significantly more neck pain (odds ratio [OR] = 3.6, p = .0286). Depending on the workspace, high-low tables increased the chance of developing neck pain (OR = 12.9, p = .0246). A screen at eye level caused less neck pain (OR = .22, p = .0610). Employees with a fixed working space were less susceptible to arm pain (OR = 0.13, p = .0058). The prevalence of arm pain was significantly higher for the vascular department compared to radiology, urology, and gynecology departments (OR = 9.2, p = .0278).
Conclusions: Regarding prevention of upper-limb pain in ultrasonograph, more attention should be paid to the work environment and more specialty to the ultrasound workstation layout. Primary ergonomic prevention could provide a painless work situation for the ultrasonographer.
Application: Further research on the ergonomic conditions of ultrasonography is necessary to develop ergonomic solutions in the work environment that will help to alleviate neck and arm pain.
Source: Claes, Frank, Berger, Jan & Stassijns, Gäetane. Human Factors, 2014.
The objectives of this study were to develop a questionnaire that evaluates the perception of nursing workers to job factors that may contribute to musculoskeletal symptoms, and to evaluate its psychometric properties. Internationally recommended methodology was followed: construction of domains, items and the instrument as a whole, content validity, and pre-test. Psychometric properties were evaluated among 370 nursing workers. Construct validity was analyzed by the factorial analysis, known-groups technique, and convergent validity. Reliability was assessed through internal consistency and stability. Results indicated satisfactory fit indices during confirmatory factor analysis, significant difference (p < 0.01) between the responses of nursing and office workers, and moderate correlations between the new questionnaire and Numeric Pain Scale, SF-36 and WRFQ. Cronbach's alpha was close to 0.90 and ICC values ranged from 0.64 to 0.76. Therefore, results indicated that the new questionnaire had good psychometric properties for use in studies involving nursing workers.
Source: Orpinelli Coluci, Marina Zambon & Costa Alexandre, Neusa Maria. (2014). Applied Ergonomics, 45 (6), p. 1588-1596.
Pushing and pulling are potential risk factors for work-related low back disorders (WRLBDs). While several studies have evaluated differences in work methods related to work experience, such evidence for dynamic pushing and pulling is limited. Eight novices and eight experienced workers completed dynamic push/pull tasks using a cart weighted to 250% of individual body mass in two different configurations (preferred vs. elbow handle heights). Multiple measures [hand forces, torso kinematics and kinetics, and required coefficient of friction (RCOF)] were obtained to assess WRLBD and slip risks. Experienced workers generated higher medio-lateral hand forces, during both pulls and pushes, though with a more substantial difference during pushes (∼74%), and which involved the use of hand force components other than to move the cart in an anterior-posterior direction. Experienced workers also had lower peak torso kinematics in flexion/extension and lateral bending, and lower torso flexion/extension kinetics. The latter is suggestive of a lower risk for WRLBDs, though levels of exposures to WRLBD risk were low to moderate in both groups and were often relatively small and inconsistent across the task configurations. Group-level differences in RCOF were quite small, indicating a comparable slip risk between the two groups. Thus, it was considered inconclusive whether the work methods used by experienced workers during dynamic pushing and pulling are advantageous regarding WRLBD and slip risks.
Source: Lee, Jungyong, Nussbaum, Maury A., Kyung, Gyouhyung. (2014). International Journal of Industrial Ergonomics, 44(5), 647-653.
Plus de Messages Page suivante »