Ergonomics - 2,432 entries found
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Ergonomic checkpoints in agriculture
Based on good practices, this manual presents practical and concrete guidance on easy-to-implement ergonomic improvements in the agricultural sector, particularly in developing countries. The checkpoints each describe an action, indicate why it is necessary and how to carry it out, and provide further hints and points to remember. They focus on ergonomically designed tools and on best techniques for handling materials and arranging workstations, physical environments, welfare facilities, teamwork methods and community cooperation.
ILO Publications, International Labour Office, 1211 Genève 22, Switzerland, 2012. xxvi, 234p. Illus. Price: CHF 40.00; USD 45.00; GBP 35.00; EUR 40.00. Downloadable version free of charge.
Ergonomic_checkpoints_in_agriculture_[INTERNET_FREE_ACCESS] [in English]
Yoo I.G., Lee J., Jung M.Y., Lee J.H.
Effects of wearing the wrong glove size on shoulder and forearm muscle activities during simulated assembly work
This study was performed to determine the changes in electromyography activity in the shoulder and forearm muscles when using the bare hands, well-fitting gloves and gloves that are one size smaller or one size larger for simulated assembly operations. Sixteen asymptomatic seated workers with normal hands and no obvious deformities, skin diseases, or allergies were recruited and were asked to simulate assembly operations. It was found that wearing the wrong glove size led to a decrease in forceful activation of the forearm muscle and a compensatory increase in shoulder movement. In contrast, use of the bare hands or wearing well-fitting gloves led to effective forearm muscle activation, which decreased inefficient shoulder movement. These data indicate that wearing the wrong glove size will lead to continuous inefficient use of the forearm and shoulder muscles, and result in overuse of the shoulder.
Industrial Health, Sep. 2011, Vol.49, No.5, p.575-581. Illus. 24 ref.
Effects_of_wearing_the_wrong_glove_size_[INTERNET_FREE_ACCESS] [in English]
Computer work - Relieving pain with only two minutes per day
Travail à l'ordinateur - Soulager la douleur en seulement deux minutes par jour [in French]
This article summarizes the findings of a study on the effectiveness of small amounts of daily exercise (2-12 min) for relieving neck/shoulder pain in healthy adults during work on computers. It is concluded that training of just two minutes per day can already bring significant relief in musculoskeletal pain.
Travail et santé, Dec. 2011, Vol.27, No.4, p.16-17. Illus. 1 ref.
Travail_à_l'ordinateur_[BUY_THIS_ARTICLE].pdf [in French]
Driessen M.T., Proper K.I., Anema J.R., Knol D.L., Bongers P.M., van der Beek A.J.
The effectiveness of participatory ergonomics to prevent low-back and neck pain - Results of a cluster randomized controlled trial
The aim of this randomized controlled trial (RCT) was to investigate the effectiveness of a participatory ergonomics (PE) programme to prevent low-back and neck pain. A total of 37 departments were randomly allocated to either the intervention (PE) or control group (no PE). The randomization procedure resulted in 19 intervention departments (1472 workers) and 18 control departments (1575 workers). During a six-hour meeting, working groups followed the PE steps and composed and prioritized ergonomic measures aimed at preventing low-back and neck pain. Subsequently, working groups were requested to implement the ergonomic measures in the departments. The primary outcomes were low-back and neck pain prevalence and secondary outcomes were pain intensity and duration. Data were collected by questionnaires at baseline, and after 3, 6, 9 and 12-months follow-up. After 12 months, the intervention was not more effective than the control group in reducing the prevalence of low-back and neck pain or reducing pain intensity and duration. However, PE was more effective in the recovery from low-back pain.
Scandinavian Journal of Work, Environment and Health, Sep. 2011, Vol.37, No.5, p.383-393. Illus. 40 ref.
The_effectiveness_of_participatory_ergonomics_[INTERNET_FREE_ACCESS] [in English]
Wijk K., Mathiassen S.E.
Explicit and implicit theories of change when designing and implementing new ergonomic interventions - A systematic literature review
This systematic literature review focuses on the theories concerning change processes upon which ergonomic interventions are based. It involved a systematic search of 13 literature databases from which 30 peer-reviewed intervention studies published between 2000 and 2007 provided sufficient information for the change process theory to be identified. Thirteen studies referred to an explicit theory of change, the most common being participatory theory, while in 17 studies, the change theory could only be discerned indirectly from the described intervention strategy. Twenty-five studies explained the reason for choosing their strategy, with a clear reference to theory or previous research, whereas five provided only a weak background. Four categories of intervention strategies for change were identified: changes targeting the individual; changes focusing on the work environment; changes relying on interactions between people; structural and organizational changes. Implications of these findings are discussed.
Scandinavian Journal of Work, Environment and Health, Sep. 2011, Vol.37, No.5, p.363-375. Illus. 100 ref.
Explicit_and_implicit_theories_[BUY_THIS_ARTICLE] [in English]
ILO_LABORDOC_[INTRANET_ACCESS] [in English]
St-Vincent M., Vézina N., Bellemare M., Denis D., Ledoux E., Imbeau D.
Interventions in ergonomics
L'intervention en ergonomie [in French]
This book presents a modern view of ergonomic interventions, describing the main steps to be followed from the analysis of needs to the follow-up of implemented changes. It includes a discussion on the practical aspects of interventions, and proposes practical tools. Based on the views of practicing ergonomists, it is primarily aimed at teachers and ergonomics students.
Editions Multimondes, 930 rue Pouliot, Québec G1V 3N9, Canada, 2011, xii, 360p. Illus. Bibl.ref.
L'intervention_en_ergonomie_[BUY_THIS_DOCUMENT] [in French]
Design of premises - New era in metallic framework
Conception des locaux - Changement d'ère dans la charpente métallique [in French]
This article presents the new workshop of a French metallic framework manufacturer, four times the surface area of the previous premises. The layout was planned while keeping focused on employees' working conditions.
Travail et sécurité, Nov. 2011, No.722, p.36-38. Illus.
Conception_des_locaux_[INTERNET_FREE_ACCESS] [in French]
Waste sorting centre - Safety and health in waste sorting
Centre de tri - La prévention profite du tri des déchets [in French]
This richly- illustrated article presents the activities of an enterprise specialized in waste sorting. The opening in 2011 of a state-of-the art sorting plant contributed towards viewing waste truly as a raw material.
Travail et sécurité, Nov. 2011, No.722, p.2-11. Illus.
Centre_de_tri_[INTERNET_FREE_ACCESS] [in French]
Driessen M.T., Proper K.I., Anema J.R., Knol D.L., Bongers P.M., van der Beek A.J.
Participatory ergonomics to reduce exposure to psychosocial and physical risk factors for low back pain: Results of a cluster randomised control trial
This study investigated the effectiveness of a participatory ergonomics programme to reduce workers' exposure to psychosocial and physical risk factors. 3047 workers from 37 departments of four Dutch companies participated in this cluster randomised controlled trial; 19 departments (1472 workers) were randomised to an intervention group (participatory ergonomics) and 18 departments (1575 workers) to a control group (no participatory ergonomics). During a 6h meeting guided by an ergonomist, working groups devised ergonomic measures to reduce psychosocial and physical workload and implemented them within three months in their departments. Data on psychosocial and physical risk factors for low back pain and neck pain were collected at baseline and after six months. Psychosocial risk factors were measured using the Job Content Questionnaire and physical risk factors using the Dutch Musculoskeletal Questionnaire. Intervention effects were studied using multilevel analysis. Intervention group workers significantly increased on decision latitude and decision authority compared to control workers. However, exposure to awkward trunk working postures significantly increased in the intervention group compared to the control group. No significant differences between the intervention and control group were found for the remaining risk factors. Participatory ergonomics was not effective in reducing exposure to psychosocial and physical risk factors for low back pain and neck pain among a large group of workers.
Occupational and Environmental Medicine, Sep. 2011, Vol.68, No.9, p.674-681. Illus. 40 ref.
Participatory_ergonomics_to_reduce_exposure_[BUY_THIS_ARTICLE] [in English]
Griffith L.E., Wells R.P., Shannon H.S., Walter S.D., Cole D.C., Côté P., Frank J., Hogg-Johnson S., Langlois L.E.
Translation of mechanical exposure in the workplace into common metrics for meta-analysis: A reliability and validity study
Previous work assessed inter-rater reliability of expert raters using six scales to estimate the intensity of literature-based mechanical exposures. The objectives of this study were to estimate the impact on the inter-rater reliability of using non-expert (NE) raters and to assess the validity of rating scales. Expert and non-expert (students with training in biomechanics) rated reports from published articles that described mechanical exposure into a set of common metrics. Seven-point scales were used to represent three dimensions of mechanical exposures at work: trunk posture; weight lifted or force exerted; spinal loading. Findings support using NE raters to estimate the intensity of literature-based mechanical exposure metrics using a common set of scales which can be applied across epidemiologic studies. One would need to average the ratings of at least five NE raters to have an acceptable level of reliability.
Occupational and Environmental Medicine, Aug. 2011, Vol.68, No.8, p.605-610. Illus. 42 ref.
Translation_of_mechanical_exposure_[BUY_THIS_ARTICLE] [in English]
Öztürk N., Esin M.N.
Investigation of musculoskeletal symptoms and ergonomic risk factors among female sewing machine operators in Turkey
This cross-sectional study aimed to identify the prevalence of musculoskeletal symptoms and ergonomic risks in female sewing machine operators at a textile company. The study sample comprised all 283 female sewing machine operators employed in the company. Data were collected through the use of the adapted Nordic Musculoskeletal Questionnaire and by direct observations via the rapid upper limb assessment (RULA) to determine ergonomic risks. RULA is a validated tool for assessment of ergonomic risks. The mean age of the women was 30.2 and the mean number of years of employment was 13.4. The highest prevalence rates for musculoskeletal symptoms were in the trunk (62.5%), neck (50.5%) and shoulder (50.2%); 65% of the women had experienced musculoskeletal pain or discomfort over the previous six months. Pain intensity of these symptoms assessed with a visual analogue scale was found to be 3.5. Results of the RULA scores were found to be high (average of 6.9, with all scores >5). Implications of these findings are discussed.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.585-591. 38 ref.
Choobineh A., Motamedzade M., Kazemi M., Moghimbeigi A., Pahlavian A.H.
The impact of ergonomics intervention on psychosocial factors and musculoskeletal symptoms among office workers
This study aimed to investigate psychosocial risk factors and musculoskeletal symptoms among office workers of an Iranian oil refinery and also to examine the subsequent effects of ergonomics intervention on musculoskeletal discomfort and psychosocial risk factors. A total of 73 office workers as a case group and 61 office workers as a control group were randomly selected and examined. The Nordic Musculoskeletal Disorders Questionnaire and the Persian version of the Job Content Questionnaire (P-JCQ) were used as collecting data tools before and after the interventional program. Low back problem (28.8%) was found to be the most common problem among the office workers. Significant differences found between prevalence rates of reported musculoskeletal in upper back, lower back and feet/ankle regions before and after intervention. Findings showed that psychosocial variables were not affected by the intervention which consisted in ergonomic traning sessions. The only variables on the P-JCQ that were significantly different pre/post intervention are the physical variables: physical job demands, physical exertion and physical isometric load. None of the other psychosocial variables were found to be significant. With management support, improvements in all office workstation components were made successfully.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.671-676. 74 ref.
Mehta R.K., Horton L.M., Agnew M.J., Nussbaum M.A.
Ergonomic evaluation of hospital bed design features during patient handling tasks
The purpose of this study was to evaluate, during two patient handling tasks, the physical demands resulting from alternative hospital bed design features. Twenty-four novice participants were involved in two laboratory-based studies. The effects of a steering lock and adjustable push height were evaluated during a patient transportation task using perceptual responses and measures of performance and physical demands, and the effect of a bed contour feature was determined based on patient sliding distance during repeated bed raising/lowering. Use of the steering lock reduced the number of adjustments during bed manoeuvring by 28% and decreased ratings of physical demands. Use of the adjustable push height reduced shoulder moments by 30%. With the contour feature, patient sliding distance was reduced by 40% over 12 raise/lower cycles. These results suggest that the steering lock and adjustable push height features can reduce physical demands placed on healthcare workers during patient transportation tasks.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.647-652. Illus. 26 ref.
Dutta T., Holliday P.J., Gorski S.M., Baharvandy M.S., Fernie G.R.
The effects of caregiver experience on low back loads during floor and overhead lift maneuvering activities
This study investigated the effects of caregiver experience on peak external forces and moments generated at the L5/S1 joint of the low back when maneuvering loaded floor-based and overhead-mounted patient lifting devices. Twenty caregivers were divided into more-experienced and less-experienced groups based on the product of two factors: their years of lifting experience and the frequency of lifting the caregivers had done in the past. Ground reaction forces and moments as well as motion capture data were recorded while caregivers performed five different maneuvering tasks with both lifts in each of three conditions (caregiver subjects worked alone, as the primary caregiver in a pair, and as the secondary caregiver in a pair). Six outcome measures (net external forces and moments at the L5/S1 joint) were recorded. Multivariate analyses of variance of all net external forces and moments were done separately for the floor and overhead lifts. A significant effect of experience level was found for the floor lift but not for the overhead lift. A follow-up univariate analysis of floor lift activities found significant differences between more-experienced and less-experienced caregivers. Implications of these findings are discussed.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.653-660. Illus. 45 ref.
Manual handling and training - Contribution of ergonomic analysis
Manutention et formation - L'apport de l'analyse ergonomique [in French]
This article describes an ergonomic intervention aimed at reducing musculoskeletal hazards among manual handling workers at a Quebec, Canada sawmill. The intervention consisted of an ergonomic analysis of workplaces based on observations, together with training drawing from the knowledge of experienced workers.
Travail et santé, Sep. 2011, Vol.27, No.3, p.38-42. Illus. 6 ref.
Li K.W., Yu R.
Assessment of grip force and subjective hand force exertion under handedness and postural conditions
The Borg CR-10 scale has been used to quantify the perception of physical exertion. This study was conducted to test the grip force of male workers on four levels of the CR-10 scale under experimental conditions. It was found that the subjects applied higher grip forces than they perceived at levels 2, 5, and 7 on the scale. The grip forces between dominant and non-dominant hands at low CR-10 levels were negligible. The grip forces were significantly different between the two hands at level 10. Similar results were found for the postural conditions. A follow-up experiment was conducted to estimate the subjective rating when applying a pre-determined grip force under the same conditions. Regression models were established to link the relationship between the subjective rating and hand force. The estimated ratings were lower than the actual values under all the tested conditions, even though the models have high R² values.
Applied Ergonomics, Nov. 2011, Vol.42, No.6, p.929-933. Illus. 22 ref.
Balasubramanian V., Dutt A., Rai S.
Analysis of muscle fatigue in helicopter pilots
Helicopter pilots espouse ergonomically unfavourable postures and endure vibrations which result in low back pain. The objective of this study was to investigate the effects of a helicopter flight on pilots back and shoulder muscles using surface electromyography (sEMG) analysis. This study also correlates low back pain symptoms from Rehabilitation Bioengineering Group Pain Scale (RBGPS) questionnaire with muscle fatigue rates obtained. RBGPS was administered on 20 Indian Coast Guard helicopter pilots. sEMG was acquired before and after flight from erector spinae and trapezius muscles in 8 of these 20 pilots. Statistical analysis of time and frequency domain parameters indicated significant fatigue in right trapezius muscle due to flying. Muscle fatigue correlated with average duration of flight, total service as pilot, pain and total flying hours. However, muscle fatigue weakly correlated with body mass index.
Applied Ergonomics, Nov. 2011, Vol.42, No.6, p.913-918. Illus. 24 ref.
Jin S., Mirka G.A.
The effect of a lower extremity kinematic constraint on lifting biomechanics
Leaning against a stationary barrier during manual materials handling tasks is observed in many industrial environments, but the effects of this kinematic constraint on low back mechanics are unknown. Thirteen participants performed two-handed lifting tasks using both a leaning posture and no leaning posture while trunk kinematics, muscle activity and ground reaction force were monitored. Results revealed that lifting with the leaning posture required significantly less activity in erector spinae (26% vs. 36% MVC) and latissimus dorsi (8% vs. 14% MVC), and less passive tissue moment compared with the no leaning posture. Peak sagittal accelerations were lower when leaning, but the leaning posture also had significantly higher slip potential as measured by required coefficient of friction. The results suggest that the leaning lifting strategy provides reduced low back stress, but does so at the cost of increased slip potential.
Applied Ergonomics, Nov. 2011, Vol.42, No.6, p.867-872. Illus. 17 ref.
Helland M., Horgen G., Kvikstad T.M., Garthus T., Aarås A.
Will musculoskeletal and visual stress change when visual display unit (VDU) operators move from small offices to an ergonomically optimized office landscape?
This study investigated the effect of moving from small offices to a landscape environment for 19 visual display unit (VDU) operators. The operators reported significantly improved lighting and glare conditions. Furthermore, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting conditions and visual discomfort, neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices. This correlation disappeared after the lighting system in the office landscape was improved. Other findings are discussed. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view.
Applied Ergonomics, Nov. 2011, Vol.42, No.6, p.839-845. Illus. 45 ref.
Keir P.J., Sanei K., Holmes M.W.
Task rotation effects on upper extremity and back muscle activity
Job rotation is an intuitive approach to distributing work to minimize muscular fatigue. The purpose of this study was to evaluate rotation between lifting and gripping on muscle activity and effort. Ten male participants performed all four combinations of two 15 min tasks in 30 min trials split between separate days to prevent fatigue. The tasks of lifting a 12 kg box and gripping at 20% of maximum were performed 6 times per minute. Muscle activity (percentiles, gaps) and perceived effort were significantly affected by the task combinations. The forearm and upper erector spinae muscles did not benefit as greatly from rotating between lifting and gripping tasks as the lower erector spinae, deltoid or trapezius. In addition to gross task differences, overlaps in muscle activity between "low back" and "upper extremity" tasks must be considered when creating effective job rotation schemes.
Applied Ergonomics, Nov. 2011, Vol.42, No.6, p.814-819. Illus. 18 ref.
Milosavljevic S., Gregory D.E., Pal P., Carman A.B., Milburn P.D., Callaghan J.P.
The interaction between skill, postures, forces and back pain in wool handling
Wool handling is an important rural occupation where workers process 200 or more fleeces daily, separating them into various quality components. Loads and postures they experience carry substantial risk of low back pain (LBP). Although a formal skill training structure exists, interaction with loads and LBP is unknown. This study examined whether skill and LBP influenced trunk postures and loads of 60 wool handlers representing three skill levels. LBP prevalence ranged from 20% for junior (lowest skill) to 45% for open class (highest skill) wool handlers. Open class wool handlers demonstrated increased lateral bend and more axially twisted postures, generating greater medio-lateral shear forces and lateral bend and axial twist moments. LBP was associated with open class wool handlers spending more time in severe axially twisted postures. These findings suggest that skill-based training needs to be reviewed to reduce the quantity of axially twisted posture which may help reduce the prevalence of LBP in this workforce.
Applied Ergonomics, Nov. 2011, Vol.42, No.6, p.801-806. Illus. 15 ref.
Cascioli V., Heusch A.I., McCarthy P.W.
Does prolonged sitting with minimum legroom affect the flexibility of a healthy subject and their perception of discomfort?
This study examined for differences in subjective ratings of discomfort and comfort and objective measures of hamstring, lumbar and neck flexibility in 24 healthy young subjects following 4h of sitting on stacking chairs with or without limited legroom. When comparing the limited and unlimited legroom groups for differences in subjective and objective measures over 4h, no significant findings were seen at the 5% level of confidence. However, differences in buttock, neck, shoulder and average discomfort were significantly negatively correlated to differences between post-warm up sit-reach scores. The difference in buttock discomfort was significantly negatively correlated to the difference between pre-warm up sit-reach scores, post-sitting/pre-warm up and pre-sitting/post-warm up sit-reach scores. Implications of these findings are discussed.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.471-480. Illus. 61 ref.
Does_prolonged_sitting.pdf [in English]
Öztürk N., Esin M.N.
Investigation of musculoskeletal symptoms and ergonomic risk factors among female sewing machine operators in Turkey
This cross-sectional study aimed to identify the prevalence of musculoskeletal symptoms and ergonomic risks in female sewing machine operators at a textile company. The sample included 283 sewing machine operators, of mean age 30.2 years. Data were collected by means of an adapted Nordic Musculoskeletal Questionnaire and by direct observations via the rapid upper limb assessment (RULA) to determine ergonomic risks. Women have both a high level of musculoskeletal disorders and high ergonomic risks. "Feeling pressured because of work" was the strongest predictor. Other findings are discussed.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.585-591. 38 ref.
Investigation_of_musculoskeletal_symptoms.pdf [in English]
Samani A., Fernández-Carnero J., Arendt-Nielsen L., Madeleine P.
Interactive effects of acute experimental pain in trapezius and sored wrist extensor on the electromyography of the forearm muscles during computer work
This study investigated the interactive effects of shoulder pain and wrist extensor muscle soreness on surface electromyography (EMG) during computer mouse work. On day one, 12 subjects performed computer work with/without acute muscle pain induced in the trapezius muscle. Subsequently, eccentric exercise was performed to induce delayed onset muscle soreness (DOMS) in wrist extensor muscles. In presence of DOMS on day two, computer work recordings with/without pain were repeated. EMG signals were recorded from the descending part of trapezius bilaterally, flexor carpi ulnaris and extensor carpi radialis brevis. Experimental muscle pain in trapezius led to a decrease in the muscular activity of the wrist extensor and decreased the relative rest time in the wrist flexor even in presence of DOMS. These results suggest that shoulder pain plays a role in the coordination of wrist flexors and extensors during computer work.
Applied Ergonomics, July 2011, Vol.42, No.5, p.735-740. Illus. 58 ref.
Ferguson S.A., Marras W.S., Gary Allread W., Knapik G.G., Vandlen K.A., Splittstoesser R.E., Yang G.
Musculoskeletal disorder risk as a function of vehicle rotation angle during assembly tasks
The objective of this study was to quantify exposures to musculoskeletal disease (MSD) risk factors as a function of vehicle rotation angle and position during assembly tasks. The study was conducted at the Center for Occupational Health in Automotive Manufacturing (COHAM) Laboratory. Twelve subjects participated in the study. The vehicle was divided into seven regions, (three interior, two underbody and two engine regions) representative of work areas during assembly. Three vehicle rotation angles were examined for each region. Exposure was assessed on the spine loads and posture, shoulder posture and muscle activity, neck posture and muscle activity as well as wrist posture. In all regions, rotating the vehicle reduced musculoskeletal exposure. In five of the seven regions, 45° of vehicle rotation represented the position that reduced MSD exposure most. Two of the seven regions indicated 90° of vehicle rotation had the greatest impact for reducing MSD exposure. This study demonstrated that vehicle rotation shows promise for reducing exposure to risk factors for MDS during automobile assembly tasks.
Applied Ergonomics, July 2011, Vol.42, No.5, p.699-709. Illus. 28 ref.
Musculoskeletal_disorder_risk.pdf [in English]
Tak S., Buchholz B., Punnett L., Moir S., Paquet V., Fulmer S., Marucci-Wellman H., Wegman D.
Physical ergonomic hazards in highway tunnel construction: Overview from the construction occupational health program
This report provides an overview of physical ergonomic exposures in highway construction work across trades and major operations. For each operation, the observational method "PATH" (Posture, Activity, Tools and Handling) was used to estimate the percentage of time that workers spent in specific tasks and with exposure to awkward postures and load handling. The observations were carried out on 73 different days, typically for about 4 h per day, covering 120 construction workers in five different trades: labourers, carpenters, ironworkers, plasterers, and tilers. Non-neutral trunk postures (forward or sideways flexion or twisting) were frequently observed, representing over 40% of observations for all trades except labourers (28%). Kneeling and squatting were common in all operations, especially tiling and underground utility relocation work. The handling of loads was frequent, especially for plasterers and tilers, with a range of load weights but most often under 15 pounds. The results of this study provide quantitative evidence that workers in highway tunnel construction operations are exposed to ergonomic factors known to present significant health hazards.
Applied Ergonomics, July 2011, Vol.42, No.5, p.665-671. Illus. 33 ref.
Calvet B., Charlebois C.
Workplace layout taking into account work activities - A positive experience
Aménagement versus activités de travail - Un projet prometteur [in French]
In the printing industry, it is estimated that 43% of accidents are caused by postures and efforts and 23% by the layout of premises. This article presents a participatory ergonomic approach that resulted in improvements in the layout of a unit of a newspaper printing plant in Quebec, Canada.
Travail et santé, June 2011, Vol. 27, No.2, p.22-25. Illus. 4 ref.
OSH in thermal units: Good practices' manual
A SST em unidades termais: Manual de boas prácticas [in Portuguese]
Main topics covered by this manual of best practices in occupational safety and health in thermal centres: overview of the thermal sector in Portugal; promoting prevention in thermal centres; occupational risk assessment; ergonomic assessment of a job in balneotherapy; fire prevention and fighting; safety signalling; causes of accidents and accident costs.
Centro tecnológico das instalações e dos equipamentos da saúde (CETIES), Portugal, 2011. 338p. Illus. 22 ref. + CD-ROM.
Chow D.H.K., Li M.F., Lai A., Pope M.H.
Effect of load carriage on spinal compression
The objective of this study was to investigate the effect of various load carriage methods on spinal loading over time by measuring spinal compression. Eight male adult participants were asked to carry a load equivalent to 15% of their body weight either anteriorly or posteriorly for 20 min followed by 10 min of recovery. Their statures were measured before load carriage and every 2min after carrying the load. The sequence of loading conditions was randomized and the participants took a 20-min rest with Fowler's posture for spinal length recovery prior to each testing condition. The amount of spinal compression was found to be associated with carrying duration. Spinal compression during anterior carriage was larger than that of posterior carriage. There was a mild recovery of spinal compression after the removal of the load for both the anterior and posterior carriage conditions.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.219-223. Illus. 33 ref.
DiDomenico A., Nussbaum M.A.
Effects of different physical workload parameters on mental workload and performance
The design and evaluation of an occupational task should include an assessment of mental workload, since excessive levels of mental workload can cause errors or delayed information processing. Physically demanding work that is performed concurrently with a cognitive task may impact mental workload by impairing mental processing or decreasing performance. The objective of this study was to determine whether there is a differential effect of various types of physical activity on both mental workload and cognitive performance. Objective and subjective assessment tools (heart rate variability and visual analogue scale) were used as indicators of mental workload, while correct responses during an arithmetic task reflected levels of performance. Thirty participants performed a combination of tasks involving both physical and mental workload. Changes in subjective ratings generally corresponded to changes in both performance on the arithmetic task and objective mental workload assessment. Some discrepancies occurred at the highest physical force exertion level as participants perceived an increase in effort to maintain the same level of performance.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.255-260. Illus. 31 ref.
Kee D., Chung M.K., Kim J.H.
Legal system and its effect for prevention of work-related musculoskeletal disorders in Korea
This article presents the legislation of occupational safety and health regulations for prevention of WMSDs in Korea and investigates its effects through the example of an ergonomic intervention effort in a major motor company. In Korea, WMSDs incidence rates had increased from 1999 to 2003. In 2002, the Korean government established a law prescribing employers' duty of preventing WMSDs, which became effective in July, 2003. It requires that all employers should execute the examination of WMSDs risk factors for eleven designated tasks every three years. In addition to this legal obligation, some large companies voluntarily established an ergonomic intervention program by carrying out in-depth assessments for stressful tasks. Thanks to Korean government and industry's efforts, the incidence rates of WMSDs have continually decreased from 2004 onwards.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.224-232. Illus. 20 ref.
Kihlstedt A., Hägg G.M.
Checkout cashier work and counter design - Video movement analysis, musculoskeletal disorders and customer interaction
This study was conducted in order to analyse checkout cashiers' movements at a checkout counter during interaction with customers and the prevalence of work-related stress and musculoskeletal disorders in checkout cashiers. In one shop, six cashiers were videotaped during the workday and 50 cashiers from seven shops from the same chain of stores responded to a questionnaire. Cashier activities and movements, customer interaction and counter design issues were analysed from the video data. Prevalence of work-related stress and musculoskeletal disorders was obtained from the questionnaire. It was found that 76% of all items were manually turned or angled. With a better adjustment of the scanner and a standardised positioning of the barcode, many of these movements could be avoided. Furthermore the prevalence of musculoskeletal disorders was quite high (68% for the neck). The questionnaire results showed that many cashiers experienced stress. The behaviour of the customers was the major cause of stress. Other sources of stress arose from bad design or function of the computer system or other technical equipment.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.201-207. Illus. 19 ref.
Tak S., Calvert G.M.
The estimated national burden of physical ergonomic hazards among US workers
The objective of this study was to estimate the national burden of physical ergonomic hazards among working adults in the United States. The population prevalence and the total number of workers who are exposed to physical ergonomic hazards, such as vibration, working in cramped space, kneeling, body bending or twisting, climbing and repetitive motions were estimated using Occupational Information Network (O*NET) data and the Occupational Employment Statistics (OES) from the Bureau of Labor Statistics (BLS), stratified by occupation title. Repetitive motion was the most prevalent of all ergonomic hazards (27% of workers are estimated to be exposed continually). Bending or twisting of the body more than half their time at work was also common, involving over 32 million workers (25% of the workforce). Kneeling, crouching, stooping, or crawling was another ergonomic hazard that 14 million workers perform more than half their time at work. Almost 4 million workers climb ladders, scaffolds, poles, etc. for more than half their time at work. It is also estimated that over 13 million workers (10% of the workforce) are exposed to cramped workspace that requires getting into awkward positions every day. Finally, about 3.5 million workers (2.7% of the workforce) are estimated to be exposed to whole body vibration every day.
American Journal of Industrial Medicine, 2011, Vol.54, p.395-404. Illus. 36 ref.
Shiri R., Martimo K.P., Miranda H., Ketola R., Kaila-Kangas L., Liira H., Karppinen J., Viikari-Juntura E.
The effect of workplace intervention on pain and sickness absence caused by upper-extremity musculoskeletal disorders
The aim of this study was to assess the effect of an ergonomic intervention on pain and sickness absence caused by upper-extremity musculoskeletal disorders. It was conducted in the form of a randomized controlled study including 177 subjects aged 18-60 years seeking medical advice due to upper-extremity symptoms. Workplace ergonomic improvements were made in the intervention group. Data on symptoms and sickness absences were gathered during one-year follow-up. Pain intensity, pain interference with work, leisure time, or sleep did not differ between the intervention and control group during the one-year follow-up. During the first three months of follow-up, the percentage of employees with sickness absence due to upper-extremity or other musculoskeletal disorders did not differ between the intervention and control group, but the total number of sickness absence days in the intervention group was about half of that in the control group.
Scandinavian Journal of Work, Environment and Health, Mar. 2011, Vol.37, No.2, p.120-128. Illus. 23 ref.
The_effect_of_workplace.pdf [in English]
Cheng M.K., Lee D., Jeong C.
The effect of zoomable user interfaces and user age in searching for a target with a mouse on a two-dimensional information space
A zoomable user interface (ZUI) is a useful function to help users deal with large information spaces displayed within a screen. Although used in many applications, ZUIs have not been sufficiently studied in terms of usability. Usability problems may be more crucial for older people than younger ones. The objective of this study was to examine the effects of zoom factors for younger and older adults on mouse-based information searching tasks in a map-type two-dimensional information space. Twenty four volunteers (twelve users per age group) participated in the experiments. Task completion time, number of operations, and number of errors were selected as performance measures, and a subjective assessment of satisfaction was collected. Older adults used the tested ZUIs less efficiently and precisely than younger adults. Potential implications of the age-related performance differences and the effects of ZUI functions are discussed. The findings can be used as basic resources in designing various web services and applications for older computer users.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.191-199. Illus. 38 ref.
Leong C.K.W., Hoffmann E.R., Good M.C.
Ballistic movements on data-entry keypads
Research to date on movement times on data-entry keypads has assumed that the movements are made under visual control. However this is often not the case. A survey of commonly used keypads on devices such as mobile phones and ATMs shows that there is a need to study movement times when the index of difficulty values are less than those for which movements are likely to be made under visual control. A series of experiments on simulated and real keypads indicates that the ballistic form of movement is generally valid and may be modelled by a modification of the ballistic movement time model. A model is developed for the time required to complete sequences of number entries containing up to five numbers. In this model, the movement times are related to the square-root of the sum of the movement amplitudes.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.180-190. Illus. 27 ref.
Sorensen C.J., Haddad O., Campbell S., Mirka G.A.
The effect of stance width on trunk kinematics and trunk kinetics during sagitally symmetric lifting
The sports biomechanics literature has documented changes in trunk and lower extremity kinematics and muscle coactivation patterns as a function of stance width during high force dead lift and squat exercises. The focus of the current study was to explore whether these lifting stance width effects might translate into the occupational setting under more moderate load level conditions. Twelve subjects performed repetitions of a sagittally symmetric lifting and lowering task (10 kg load) under three stance width conditions: narrow (feet together), moderate (feet shoulder width) and wide (feet 150% of shoulder width). As they performed these exertions, trunk kinematics were captured using the lumbar motion monitor while the activity of the trunk muscles (erector spinae, rectus abdominis) and lower extremity muscles (gluteus maximus, vastus lateralis and vastus medialis) were evaluated using normalized electromyography. The results showed that both the range of motion and peak acceleration in the sagittal plane were significantly affected by the stance width. The muscle activation levels, however, were not significantly affected by the stance width. These results collectively would indicate that the stance width effects seen in power lifting activities do not translate well into the occupational environment where more moderate loads are typically lifted.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.147-152. Illus. 16 ref.
Raab Glina D.M., Cardoso A.S., Isosaki M., Rocha L.E.
Participatory ergonomics: Understanding the contributions of reflection groups in a hospital food service
The objective of this study was to identify how the methodology of Reflection Groups (RG) can contribute to approach social-psychological problems, so often observed as obstacles in participatory ergonomics efforts. The objective was also to verify the contributions from RG to the implementation of ergonomics recommendations. The methodology was applied to a concrete case, with the management and employees from the department of nutrition and dietetics of a cardiologic hospital in São Paulo, Brazil. Findings are discussed.
International Journal of Industrial Ergonomics, 2011, Vol.41, p.96-105. 33 ref.
Rempel D., Star D., Barr A., Blanco M.M., Janowitz I.
Field evaluation of a modified intervention for overhead drilling
Drilling holes into concrete or metal ceilings is one of the most physically demanding tasks performed in construction. The work is done overhead with rotary impact hammer drills that weigh up to 40 N. The task is associated with pain and musculoskeletal disorders at the wrist, forearm, shoulder and back. The mechanism of injury is thought to be the high forces and non-neutral shoulder and wrist postures applied during drilling. Using a participatory intervention model, feedback from 13 construction workers was used to develop a new intervention design that incorporated a wheeled tripod base and a unique method of aligning the drilling column to vertical. A different group of 23 construction workers) evaluated usability and fatigue of the new device during their regular overhead drilling in comparison with the usual method. Four of 12 usability ratings were significantly better with the intervention device compared with the usual method. Subjective shoulder fatigue was less with the new intervention. This difference was supported by objective outcome measures; the mean hand forces during drilling were 26 N with the intervention compared with 245 N with the usual method. The percentage of time with the shoulder flexed or abducted to more than 60 degrees was less with the intervention compared with the usual method. There was significantly less head extension with the intervention compared with the usual method. This study demonstrates that a new intervention device for overhead drilling has improved usability and subjective fatigue ratings compared with the usual method. These improvements are most likely due to the reduced hand forces, reduced shoulder abduction and flexion, and reduced drilling time.
Journal of Occupational and Environmental Hygiene, Apr. 2010, Vol.7, No.4, p.194-202. Illus. 23 ref.
Field_evaluation.pdf [in English]
McGorry R.W., Lin J.H., Dempsey P.G., Casey J.S.
Accuracy of the Borg CR 10 scale for estimating grip forces associated with hand tool tasks
The gripping of tools is required by many industrial operations, and an important aspect of exposure assessment is determining the grip force output of operators. Ratings of perceived exertion can provide an indirect measure of grip force; however, reports in the literature of the use of Borg CR10 scale ratings as a surrogate measure of grip force have been mixed. During a laboratory study with 16 participants, power grip forces were measured directly during three hand tool task simulations: a screwdriver task, a ratchet task and a lift and carry task, each performed at four force or load levels. Borg CR10 scale ratings reported following each trial were compared with mean, peak and integrated grip forces for the respective trials. Pearson correlations conducted on an individual basis were greatest for the screwdriver task. Correlations for integrated grip force were generally better than for mean or peak force. Correlations were also performed on data pooled for all participants, simulating a cross-sectional sampling approach. Correlations made with pooled data were weaker than when conducted on an individual basis. When the pooled data were normalized to individual maximum voluntary grip exertions, correlation generally improved but not to the level of the "individually scaled" data. Based on these findings, a protocol is proposed that could improve the strength of correlations between direct measures of grip force and ratings of perceived exertion. Differences in strength of correlation between task simulations are discussed with respect to differences observed in force distributions about the handle for the three tasks.
Journal of Occupational and Environmental Hygiene, May 2010, Vol.7, No.5, p.298-306. Illus. 34 ref.
Accuracy_of_the_Borg_CR_10.pdf [in English]
Lin J.H., McGorry R.W., Banks J.J.
Exposures and physiological responses in power tool operations: Fastening vs. unfastening threaded hardware
Powered hand tools have the potential to produce reaction forces that may be associated with upper extremity musculoskeletal disorders. This study examined and compared the kinetic and physiological impacts on operator upper extremities between the fastening and unfastening operations. Thirty-two healthy, right-handed male operators used four tools on two joint simulators at different working heights and distances in the laboratory. Three work configurations were simulated: pistol grip tools on a vertical and horizontal surface, and right angle tools on a horizontal surface. Grip force was measured on an instrumented handle attached to each tool. Muscle activity was monitored at the wrist flexor and extensor and the upper trapezius of the right arm. Paired comparisons showed that when pistol grip tools were used, the peak torque to unfasten a joint (3.7 Nm) was significantly less than to fasten the same joint (5.7 Nm). However, the exposure time was longer for unfastening cycles (98 ms more on the horizontal surface, and 107 ms more on the vertical surface). The average grip force scaled to corresponding peak tool torque revealed that the effort to react against torque was greater in unfastening cycles than in fastening cycles for all work configurations. It also showed that as a proximal stabilizer, the upper trapezius muscle had a greater activity in unfastening cycles. The kinetic and physiological responses demonstrated that unfastening fasteners, which has been neglected in the literature, have the potential to increase risk for musculoskeletal disorders and should be considered in ergonomics assessment in the workplace.
Journal of Occupational and Environmental Hygiene, May 2010, Vol.7, No.5, p.290-297. Illus. 20 ref.
Exposures_and_physiological_responses.pdf [in English]
Keyserling W.M., Wiggermann N., Werner R.A., Gell N.
Inter-worker variability in lower body postures during assembly line work: Implications for exposure assessment
This study evaluated inter-worker variability in lower body posture and work activity during highly-structured assembly line work. Data were collected from 79 assembly line workstations in an engine manufacturing plant. Because the plant utilized work teams, 4-8 workers rotated through each workstation. At least 30 min of videotape was collected from at least three workers at each workstation. A computer-assisted work sampling procedure randomly selected 200 video "freeze-frames" for each worker. Lower body postures and movements were determined for each frame and used to estimate the percentage of time the worker spent in various postures and activities. Chi-square analyses were performed for each workstation to assess the significance of inter-worker differences. Findings are discussed.
Journal of Occupational and Environmental Hygiene, May 2010, Vol.7, No.5, p.261-271. 24 ref.
Inter-worker_variability.pdf [in English]
Haukka E., Pehkonen I., Leino-Arjas P., Viikari-Juntura E., Takala E.P., Malmivaara A., Hopsu L., Mutanen P., Ketola R., Virtanen T., Holtari-Leino M., Nykänen J., Stenholm S., Ojajärvi A., Riihimäki H.
Effect of a participatory ergonomics intervention on psychosocial factors at work in a randomised controlled trial
The objective of this study was to assess the effect of a participatory ergonomics intervention on psychosocial factors among kitchen workers. It was conducted in the form of a cluster randomised controlled trial involving 504 workers in 119 municipal kitchens in four cities in Finland, from 2002 to 2005. The kitchens were randomised to 59 intervention and 60 control groups. The intervention lasted 11-14 months and was based on the workers' active participation in work analysis, planning and implementing the ergonomic changes aimed at decreasing the physical and mental workload. Mental stress, mental strenuousness of work, hurry, job satisfaction, job control, skill discretion, co-worker relationships and supervisor support were measured. Data were collected by questionnaire at baseline, at the end of the intervention, and at a 12-month follow-up. At the end of the intervention, the odds ratio (OR) of job dissatisfaction for the intervention group as compared with the control group was 3.0, of mental stress 2.3 and of poor co-worker relationships 2.3. At the 12-month follow-up, the OR of job dissatisfaction was 3.0. Analysis of the independent and joint effects of the intervention and unconnected organisational reforms showed that adverse changes were accentuated among those with exposure to both. No favourable effects on psychosocial factors at work were found. The adverse changes were due to a joint effect of the intervention and unconnected organisational reforms. The findings do not support the usefulness of this kind of intervention in changing unsatisfactory psychosocial working conditions.
Occupational and Environmental Medicine, Mar. 2010, Vol.67, No.3, p.170-177. Illus. 40 ref.
Bin W.S., Richardson S., Yeow P.H.
An ergonomics study of a semiconductors factory in an IDC for improvement in occupational safety and health
The study aimed to conduct an ergonomic intervention on a conventional line (CL) in a semiconductor factory in Malaysia, an industrially developing country (IDC), to improve workers' occupational safety and health (OSH). Low-cost and simple (LCS) ergonomics methods were used (suitable for IDCs), e.g., subjective assessment, direct observation, use of archival data and assessment of noise. It was found that workers were facing noise irritation, neck and back pains and headache in the various processes in the CL. LCS ergonomic interventions to rectify the problems included installing noise insulating covers, providing earplugs, installing elevated platforms, slanting visual display terminals and installing extra exhaust fans. The interventions cost less than 3 000 USD but they significantly improved workers' OSH, which directly correlated with an improvement in working conditions and job satisfaction. The findings are useful in solving OSH problems in electronics industries in IDCs as they share similar manufacturing processes, problems and limitations.
International Journal of Occupational Safety and Ergonomics, 2010, Vol.16, No.3, p.345-356. Illus. 28 ref.
Malińska M., Bugajska J.
The influence of occupational and non-occupational factors on the prevalence of musculoskeletal complaints in users of portable computers
The aim of the study was to assess the prevalence and intensity of musculoskeletal pain among workers who regularly use portable computers and to determine the influence of working conditions and duration of work with a portable computer. The study covered a cross-section of 300 workers. Musculoskeletal complaints were assessed with the Nordic musculoskeletal questionnaire complemented with a visual analogue scale. Working conditions were assessed by means of a questionnaire. The most prevalent faults of workstation layouts were lack of a computer desk with an adjustable keyboard tray/drawer, the lack of adjustable armrests, the absence of an external keyboard. The most frequent complaints among computer operators were headaches, low-back pain and neck pain. The use of an external keyboard reduced the intensity of shoulder pain. Other findings are discussed.
International Journal of Occupational Safety and Ergonomics, 2010, Vol.16, No.3, p.337-343. 32 ref.
Sinisammal J., Saaranen P.
Preferred handrail height for spiral stairs - A fitting trial study
Although stairways are in general thoroughly studied, there is little scientific data on spiral stairs. The purpose of this study was to determine preferred handrail heights for a spiral stairway. The most preferred handrail height for descent was 105 cm. On the other hand, 95% of the participants regarded handrail heights between 95 and 100 cm satisfactory for descending. Participants' anthropometric data was combined with the handrail height preference to develop a model to predict preferred handrail height according to the anthropometry of user populations.
International Journal of Occupational Safety and Ergonomics, 2010, Vol.16, No.3, p.329-335. Illus. 23 ref.
Wahlstedt K., Norbäck D., Wieslander G., Skoglund L., Runeson R.
Psychosocial and ergonomic factors, and their relation to musculoskeletal complaints in the Swedish workforce
A cross-sectional random sample of 1000 subjects (20-65 years old) from the national population of Sweden received a questionnaire; 70% replied, of whom 532 were occupationally active. Female gender, working with neck and/or body bent forward, arms above shoulders, and precision work tasks were predictors of musculoskeletal symptoms. Neck, shoulder, and upper back symptoms were more common in a strained situation at work (high demands, low control) (adjusted odds ratios (adjOR) 2.76, 2.80, and 2.26, respectively). Among women, neck and shoulder symptoms were more common in an iso-strain situation (high demands, low control and low social support) (adjOR 4.43 and 3.69, respectively), and low back symptoms were more common at low social support combined with a passive work situation (adjOR 3.35). No associations were found between iso-strain model and symptoms among male workers.
International Journal of Occupational Safety and Ergonomics, 2010, Vol.16, No.3, p.311-321. 46 ref.
Katsuhira J., Yamasaki S., Yamamoto S., Maruyama H.
Effects of general principles of person transfer techniques on low back joint extension moment
The purpose of this study was to examine the effects of general principles of person transfer techniques specifically on the low back joint extension moment. These effects were examined by the following measurable quantitative parameters: trunk bending angle; knee flexion angle; distance between the centres of gravity (COGs) of the caregiver and patient, representing the distance between the caregiver and patient; the vertical component of the ground reaction force representing the amount of the weight-bearing load on the caregiver's low back during transfers with and without assistive devices. Twenty students each took the role of caregiver, and one healthy adult simulated a patient. The participants performed three different transfer tasks: without any assistive device, with the patient wearing a low back belt, and with the caregiver using a transfer board. It was found that the distance between the COGs and the vertical component of the ground reaction force, but not the trunk bending and knee flexion angles, were the variables that affected the low back joint extension moment. These results suggest that the general principle of decreasing the distance between COGs is most effective for decreasing the low back joint extension moment during transfers under all conditions.
Industrial Health, Nov. 2010, Vol.48, No.6, p.796-803. Illus. 25 ref.
Effects_of_general_principles.pdf [in English]
Krause N., Burgel B., Rempel D.
Effort-reward imbalance and one-year change in neck-shoulder and upper-extremity pain among call center computer operators
The aim of this study was to investigate prospectively the independent effects of effort-reward imbalance (ERI) at work on regional musculoskeletal pain of the neck and upper extremities of call centre operators. It was conducted in the form of a one-year prospective study among 165 call centre operators in the United States who participated in an earlier randomized ergonomic intervention. Over a four-week period, ERI and 28 potential confounders were measures by means of a questionnaire at baseline. Regional upper-body pain and computer use was measured by weekly surveys for up to 12 months following the implementation of ergonomic interventions. Regional pain change scores were calculated as the difference between average weekly pain scores pre- and post-intervention. A significant relationship was found between high average ERI ratios and one-year increases in right upper-extremity pain after adjustment for pre-intervention regional mean pain score, current and past physical workload, ergonomic workstation design, and anthropometric, sociodemographic, and behavioural risk factors. No significant associations were found with change in neck-shoulder or left upper-extremity pain. Findings suggest that ERI predicts regional upper-extremity pain in computer operators working ≥20h per week. Control for physical workload and ergonomic workstation design was essential for identifying ERI as a risk factor.
Scandinavian Journal of Work, Environment and Health, 2010, Vol.36, No.1, p.42-53. 54 ref.
Martimo K.P., Shiri R., Miranda H., Ketola R., Varonen H., Viikari-Juntura E.
Effectiveness of an ergonomic intervention on the productivity of workers with upper-extremity disorders - A randomized controlled trial
The aim of this study was to investigate the effectiveness of an ergonomic intervention on productivity loss at work caused by upper-extremity disorders (UED). Workers with medically-verified UED were invited to participate. The intervention consisted of a physician contacting the worker's supervisor and an occupational physiotherapist conducting an ergonomic assessment at the worksite. Before and after the intervention, the employees self-assessed UED-related productivity loss (decreased quality and quantity of the daily work output). Differences between groups were tested at 8 and 12 weeks, and data were analysed by means of the generalized estimating equation (GEE). Altogether 177 employees were randomized. At baseline, 54% of the intervention group and 58% of the control group reported productivity loss. The magnitude of productivity loss was 17% and 20%, respectively. At 8 weeks, both the proportion and magnitude of productivity loss were lower in the intervention than the control group, but the differences were statistically significant only at 12 weeks. GEE analyses revealed the differences to be statistically significant (proportion 38% versus 52%, magnitude 12% versus 18%). The intervention only benefitted employees with 0-20% loss of productivity at baseline, not those with a higher initial productivity loss. It is concluded that early ergonomic intervention, in addition to adequate medical care, is effective in preventing and restoring self-reported productivity loss associated with UED.
Scandinavian Journal of Work, Environment and Health, 2010, Vol.36, No.1, p.25-33. Illus. 28 ref.
Takala E.P., Pehkonen I., Forsman M., Hansson G.Å., Mathiassen S.E., Neumann W.P., Sjøgaard G., Veiersted K.B., Westgaard R.H., Winkel J.
Systematic evaluation of observational methods assessing biomechanical exposures at work
This systematic literature review aimed to identify published observational methods assessing biomechanical exposures in occupational settings and evaluate them with reference to the needs of different users. A total of 30 relevant observational methods were identified. Of these, 19 had been compared with other methods, varying from expert evaluation to data obtained from video recordings or through the use of technical instruments. Generally, the observations showed moderate to good agreement with the corresponding assessments made from video recordings; agreement was the best for large-scale body postures and work actions. Wrist and hand postures as well as trunk rotation seemed to be more difficult to observe correctly. Intra- and inter-observer repeatability was reported for 7 and 17 methods, respectively, and were judged mostly moderate to good. It is concluded that with training, observers can reach consistent results on clearly-visible body postures and work activities. Many observational tools exist, but none evaluated in this study appeared to be generally superior. When selecting a method, users should define their needs and assess how results will influence decision-making.
Scandinavian Journal of Work, Environment and Health, 2010, Vol.36, No.1, p.3-24. 159 ref.
Systematic_evaluation.pdf [in English]
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