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BACKGROUND: Conducting practical studies in ergonomics requires attention to all aspects of ergonomics with a comprehensive approach and focus on continuous improvement cycles. OBJECTIVE: This study aimed to develop and present an ergonomics management model in the workplace. METHODS: This study was performed using a three-stage Delphi study with 30 experts and a fuzzy analytical hierarchy process. According to the literature review and experts' opinions, the general cycle of the ergonomics management system with eight steps was developed. New methods were formed in two of these eight steps: the 3rd step (developing an ergonomic evaluation method) and the 5th step (creating a cost-benefit evaluation method). RESULTS: The eight implementation steps of the TEMA were determined as follows: 1) Performing task analysis (TTA), 2) Ergonomic hazard identification, 3) Estimating the ergonomic index, 4) Determining control measures, 5) Evaluating cost-benefit parameter, 6) Implementing control measures, 7) Continuous monitoring, and 8) Evaluating the effectiveness of control measures. The Delphi study revealed that the number of deleted parameters includes one item (burnout), and the remaining parameters were 16 items. The mean CVI and CVR values were 0.92 and 0.80, respectively. Cronbach's alpha values for each of the physical, environmental, and cognitive components and the entire model were 0.91, 0.87, 0.85, and 0.89, respectively. CONCLUSION: Using the mentioned management model can be a practical step towards properly evaluating the most critical dimensions of ergonomics in the workplace and optimal planning to implement control measures to establish a dynamic management system to reduce ergonomic risk factors in the workplace. [ABSTRACT FROM AUTHOR]

BACKGROUND: Biomechanical simulation is an important tool in human-centred design, allowing for the assessment of comfort interactions between user, product and space, to optimize design features from an ergonomics perspective. OBJECTIVE: The aim of this study was to develop a biomechanical model for the evaluation of postural comfort levels. METHODS: The study used the scenario-based method to focus on the electronic-worker (e-worker) sedentary tablet tasks at public workplace (third-workplace) configurations. An empirical method determined work-related musculoskeletal disorders (WMSDs) risk levels. The experimental method was based on a motion-capture marker-based laboratory protocol and biomechanical model. Body postures were analysed to determine the WMSDs risk to the joints, and were compared to subjective questionnaires. RESULTS: Posture was affected by the tablet target location and workplace setting. The findings confirmed our hypothesis, that neutral-position cost functions govern human motion. Almost half of the time, the e-workers' joints tended to remain in the neutral position range; of the three third-workplaces, high-risk variability was less significant between the 'restaurant' and 'lounge' settings, compared to the 'anywhere' configuration. CONCLUSIONS: This evaluation model can contribute to optimizing comfort level in design for third-workplace settings and other sedentary work activities; it can be used to develop guidelines for minimizing work-related strain and health hazards. [ABSTRACT FROM AUTHOR]

BACKGROUND: Electric adjustable height desks (EAHD) have been promoted as an opportunity for desk based workers to stand at work but there is limited evidence that they have an effect on light physical activity. OBJECTIVE: The main objective was to determine if there would be a change in light physical activity with the introduction of EAHD. The secondary objective was to assess if there was an associated change in leisure time activity. METHODS: Activity levels were measured by step counts, self-reported activity levels and pre- and post-trial recall levels. Statistical analysis of the data was performed with the software R. Generalised linear models were fitted to the data. A Poisson regression was used for count data. Statistical hypotheses were deemed significant if their p values were less than 0.05. RESULTS: There was a significant (p < 0.001) effect on step counts associated with allocation of EAHD and a significant (p < 0.001) increase in self-reported activity for the Intervention (EAHD) group. Having an EAHD was associated with increased activity during leisure (p = 0.039). CONCLUSIONS: Activity levels, especially light physical activity, were significantly increased with the allocation of an electric adjustable height desk. This pilot study showed that the environmental change of introduction of electric adjustable height desks into an office workplace can increase physical activity and reduce sitting durations. There is limited evidence that the increase in work activity has a positive impact on leisure time activity. [ABSTRACT FROM AUTHOR]

BACKGROUND: Alternative methods of accessing the internet and performing computing-related work tasks are becoming common, e.g., using tablets or standing workstations. Few studies examine postural differences while using these alternative methods. OBJECTIVE: To assess neck and upper limb kinematics while using a tablet, laptop and desktop computer (sitting and standing). METHODS: Differences in neck flexion/extension, lateral flexion, rotation; elbow flexion/extension; wrist flexion/extension, radial/ulnar deviation; and shoulder elevation in 30 participants were assessed in four conditions, three in sitting (tablet, laptop and desktop computer) and one in standing (desktop computer). Three-dimensional motion capture recorded posture variables during an editing task. Differences between variables were determined using one-way ANOVA with Bonferroni post-hoc tests. RESULTS: Compared to the desktop (sitting), tablet and laptop use resulted in increased neck flexion (mean difference tablet 16.92°, 95% CI 12.79–21.04; laptop 10.92, 7.86–13.97, P < 0.001) and shoulder elevation (right; tablet 10.29, 5.27–15.11; laptop 7.36, 3.72–11.01, P < 0.001). There were no meaningful posture differences between the sitting and standing desktop. CONCLUSIONS: These findings suggest that using a tablet or laptop may increase neck flexion, potentially increasing posture strain. Regular users of tablets/laptops should consider adjustments in their posture, however, further research is required to determine whether posture adjustments prevent or reduce musculoskeletal symptoms. [ABSTRACT FROM AUTHOR]

Twelve recently built office work stations, where jobs imply continued use of information and communication technologies, were analyzed for ergonomic risk factors. Based on a literature review of ergonomic recommendations for computer and general office work, a checklist was devised for assistance in identifying inadequate ergonomic situations, a process that was informed by pain complaints information. RULA (Rapid Upper Limb Assessment) was selected to estimate the risk of MSDs, considering the criteria of applicability and appropriateness to the case studied. This method was applied by an occupational health and safety technician to the most critical job observed in the workplace. Criticality was estimated through observations aided by the systematic use of a checklist tailored to the specific office scenario. Recommendations for change were provided for implementation in all workplaces in the office, in order to improve work conditions, and guide the setup of a MSD prevention training program. [ABSTRACT FROM AUTHOR]

Multiple ergonomic risk assessment methods of unique structure are currently being used to direct industrial prevention initiatives focused on musculoskeletal injuries. In this study, the physical exposures required to perform an at-risk sawmill occupation were collected from 29 subjects via quantified means (surface electromyography and electrogoniometery) and used to calculate several ergonomic risk assessment methods. The aims of this study are to: 1) compare the output of the RULA, REBA, ACGIH TLV, Strain Index and OCRA ergonomic risk assessment methods, 2) examine the assessments' ability to differentiate between facilities reporting meaningfully different incidence rates, and 3) examine the effect of varying the definition of end range posture and exertion required on risk assessment scores. Risk level output assigned by all methods were not sensitive to inter facility differences in risk of injury, suggesting interpretation of risk index and component scores are needed to direct intervention. Components of all methodologies were sensitive to worker technique and facility assessed. Varying variable definition resulted in significantly different component, combined component and/or risk output scores in all methods assessed. The significant effect of posture and exertion variable definition suggests definitions taken to be interchangeable by work site evaluators are not equivalent. [ABSTRACT FROM AUTHOR]

This paper describes the physical exposures required to perform a sawmill job associated with a high incidence of upper extremity musculoskeletal injury. Exposure variables are described by multiple posture, exertion and frequency definitions and the comparability of those definitions are examined. Effective industrial prevention efforts require an accurate assessment of risk. Surface electromyography and electrogoniometry were used to quantify the physical exposures of 29 trim-saw operators in four sawmill facilities. Average wrist ranges of motion of 32, 57 and 58 degrees in wrist radial/ulnar deviation, flexion/extension and pronation/supination respectively were required to perform the job. Defining wrist range of motion by the peak postures observed versus those required to perform the primary task resulted in significantly different ranges of motion (p<0.05). Job performance required an average of 33% of maximum voluntary contraction. Repetitions per day ranged from 3,549 to 14,460. Percentage of maximum voluntary contraction was not associated with psychophysical measures of exertion. [ABSTRACT FROM AUTHOR]

Force exertion is related to low back injuries (LBI). This paper critically reviews the literature concerning cut-points for back force exertion, presents available guidelines in a concise manner, and identifies areas that need further research. The studies reviewed were grouped according to the criteria used to set the cut-point values. Most often cut-points differ than concur. The approach considering physiological, psychophysical, epidemiological, and biomechanical aspects of back force exertion meets the most known criteria and presents the lowest common denominator of instantaneous load for lifting tasks. Further experimental and epidemiological studies in peak load and cumulative exposure are necessary. Compound indices should also be developed for pushing, pulling, and carrying. Future indices should consider electromyographically determined fatigue, differential viscoelastic properties of tissues, aging, and the cross sectional area of back muscles. We hope that this paper contributes to a more systematic appraisal of back force exertion at work. [ABSTRACT FROM AUTHOR]