Our study quantified the extent of support provided by a passive arm-support exoskeleton throughout a range of postures. Mechanical support generated by the arm-support exoskeleton (SkelEx, ...Rotterdam, The Netherlands) that we tested clearly reaches its maximum at elevation angles ranging from 60° to 120°, where the required support is also highest. In contrast, for elevation angles below 30°, this exoskeleton provided significantly less support. Depending on the task, other support characteristics might be required. These results may help practitioners who are considering the adoption of an exoskeleton in the workplace. We advocate adapting mechanical support settings or effective range to the actual specific working envelope of postures.
Background: The use of arm-support exoskeletons is an emerging strategy to mechanically support workers during elevated arm tasks. In the present study, we evaluated the effects of wearing a passive exoskeleton on the shoulder moment and on the activity of six muscles in the shoulder region, in a range of elevated arm postures. Methods: Twelve participants were asked to maintain 15 static arm positions, which were combinations of different vertical elevations and horizontal abductions, both with and without the exoskeleton. The postures were composed of five elevation angles (vertical elevation: 30°-150°) and three horizonal abduction angles (HAb: 0°-60°). During the static postures, we obtained the supportive moment provided by the exoskeleton by measuring the interaction force, as well as muscle activity via electromyography of six relevant muscles: deltoid anterior, deltoid posterior, upper trapezius, lower trapezius, latissimus dorsi, and biceps brachii. We compared the moment that was required from the subjects to maintain the arm postures, as well as the muscle activity, between conditions with and without exoskeleton. Results: The supportive moment provided by the exoskeleton (0.5-6.1 Nm; up to 56% of the required moment) implied a significant reduction to the shoulder moment that needed be generated by the subject. These effects were dependent on the arm posture, though, particularly on the vertical arm elevation angle rather than horizontal abduction. Mechanical support was highest at the vertical elevation angles that were most demanding (90° and 120°). This effect caused the required moment from the subject to be relatively consistent across different shoulder angles. Muscle activity was reduced in three of the six muscles (deltoid anterior, upper trapezius, and latissimus dorsi). However, for two muscles (upper trapezius and lower trapezius), the effects were dependent on the vertical arm elevation angle and an increase in muscle activity was evident for the lower trapezius at vertical elevation 150°. Conclusion: Our results emphasize the importance of analyzing the task demands, such as working posture, when selecting or designing arm support exoskeletons.
When a person is exposed to a prolonged workload, he/she enters a fatigue phase, the indication is the decline of cognitive performance that leading to human error. As an integral part of a system, ...human contributes to system reliability; therefore, it plays an important role in potential failure. Those, it is necessary to investigate how human reliability relates to physical workload rate, in order to predict maximum work duration to eliminate potential failure. A physical experiment involving 20 participants was conducted to generate medium workload, followed by Stroop test to observe selective attention and cognitive control as a form of cognitive performance. The physical workload was observed through energy expenditure and oxygen consumption during physical activity, and cognitive performance through response error time on the Stroop test. The usage of Weibull distribution was aimed to obtain reliabilities for each participant. There was a decline in reliability for all participants from one test to the other. Based on scale and form parameters, the prediction of resting time was based on mean time to human error (MTTHE), and from this experiment, varied MTTHE from each participant were obtained. The variation was created by differences in physical performance, cognitive capabilities, and other contributing factors such as environment and time of the implementation of the experiment. From this research, it was evident that human reliability can be utilized to predict potential failure in humans, which then implies a preventive action is necessitated to prevent failure from manifesting in the shape of taking a break/rest or reducing work rhythm. The application of human reliability in human resource management can be directed towards fatigue management and operator-related operational management.
ObjectivesTo assess if improvement of working conditions related to heat stress was associated with improved kidney health outcomes among sugarcane harvest workers in Chichigalpa, Nicaragua, a region ...heavily affected by the epidemic of chronic kidney disease of non-traditional origin.MethodsBased on our findings during the 2017–2018 harvest (harvest 1), recommendations that enhanced the rest schedule and improved access to hydration and shade were given before the 2018–2019 harvest (harvest 2). Actual work conditions during harvest 2 were then observed. Serum creatinine (SCr) was measured before and at end-harvest, and cross-harvest changes in estimated glomerular filtration rate (eGFR) and incident kidney injury (IKI, ie, SCr increase by ≥0.30 mg/dL or ≥1.5 times the baseline value) were compared between harvest 1 and harvest 2 for three jobs with different physical workloads using regression modelling. Workers who left during harvest were contacted at home, to address the healthy worker selection effect.ResultsIn burned cane cutters, mean cross-harvest eGFR decreased 6 mL/min/1.73 m2 (95% CI 2 to 9 mL/min/1.73 m2) less and IKI was 70% (95% CI 90% to 50%) lower in harvest 2 as compared with harvest 1 data. No such improvements were seen among seed cutters groups with less successful intervention implementation.ConclusionKidney injury risk was again elevated in workers with strenuous jobs. The results support further efforts to prevent kidney injury among sugarcane workers, and other heat-stressed workers, by improving access to water, rest and shade. The distinction between design and implementation of such interventions should be recognised.
Objective
The aim of this study is to test the unified theory of acceptance and use of technology (UTAUT) model for explaining the intention to use exoskeletons among industrial workers.
Background
...Exoskeletons could help reduce physical workload and risk for injuries among industrial workers. Therefore, it is crucial to understand which factors play a role in workers’ intention to use such exoskeletons.
Method
Industrial workers (N = 124) completed a survey on their attitudes regarding the use of exoskeletons at their workplace. Using partial least squares (PLS) path modeling, the UTAUT model and a revised version of the UTAUT model were fitted to these data.
Results
The adapted UTAUT model of Dwivedi et al. (2017) was able to explain up to 75.6% of the variance in intention to use exoskeletons, suggesting a reasonable model fit.
Conclusion
The model fit suggests that effort expectancy (how easy it seems to use an exoskeleton) plays an important role in predicting the intention to use exoskeletons. Social influence (whether others think workers should use exoskeletons) and performance expectancy (how useful exoskeletons seem to be for work) play a smaller role in predicting the intention to use.
Applications
This research informs companies about the optimal implementation of exoskeletons by improving the determinants of acceptance among their workers.
Robots are heralded as part of a new revolution in agriculture. The agricultural robot’s capacity to reduce working time or improve working conditions is often advanced as a major contribution to ...sustainable agriculture. But the transformations of work appear to be more complex. Here we review the transformations of work subsequent to adoption of agricultural robots on the farm. We carry out a systematic review of literature using a multidisciplinary analytical framework of transformations of work. We consider four dimensions of work: 1) farm structure and the labor market; 2) work organization; 3) meaning of work; and 4) technical-economic performances. Given that the deployment of robots in agriculture is still in its early stages, most of the studies concern the automated milking system (AMS). The transformations of agricultural work represent an emerging topic dominated by a technical and economic vision of work. The major points are as follows: Concerning farm structures, we find no evidence of a relationship between robotization and a certain farm size. Concerning the labor market, there is a risk of skill- and wage-related segmentation and exclusion. The AMS is an example of an in-depth re-organization of work with a decrease in the physical workload but which is concomitant with a new mental workload of monitoring alarms. Concerning the meaning of work with AMS, the changes in the animal-human relationship lead to the possibility of new identities and new self-perceptions by farmers and workers. There is no evidence to support a reduction in working time when an AMS is installed. Finally, a synthesis of the results allows us to propose a research agenda that can better orient future research to understand the diversity of transformations of work resulting from the adoption of robots in agriculture.
Order picking (OP) is a time- and labour-intensive operation in which human-system errors can lead to deficiencies in quality. This study aimed to identify human factors-related failure modes that ...cause human-system errors and quality deficits in OP. We conducted a systematic literature review and qualitative interviews with 38 order pickers employed by 14 different companies in four countries. The literature review found 46 papers that identified eight different failure modes related to OP system design: physical workload, physical fatigue, mental fatigue, complexity, memory demand, vision, hearing, and motivation. The interview results confirmed many of the same factors noted in the literature review but also identified communication and supervision failure modes that had not been addressed before. The results illustrate human factors-related failure modes linked to OP system design, operation, and management that ultimately increase quality deficits and pick errors. Further research on human factors and OP system design interaction is warranted, as no assessment tool has been found to support engineers and managers seeking to improve system designs to reduce pick errors.
This study aims to measure the posture of a worker by analyzing the level of occupational health risk and the level of fatigue of the physical load in a posture with a high level of posture risk and ...proposes to improve posture to reduce the risk of musculoskeletal disorders. RULA is a method used to evaluate work posture, CATIA V5R20 software is used to simulate workers while doing work, and heart rate are the data used to identify the level of physical workload. The results of the work posture analysis show that the workers at station coconut husk stripping have the highest level of risk with a RULA score of 7 (red), which means that the work is very tiring and at risk of experiencing MSDs and needs to improve immediately.Based on the analysis of the classification of physical workloads, it shows that 76% of the coconut husk stripping work activity is a heavy and tiring workload category for the work. The proposed posture improvement shows a decrease in score.
Neuroergonomics is an emerging science that is defined as the study of the human brain in relation to performance at work and in everyday settings. This paper provides a critical review of the ...neuroergonomic approach to evaluating physical and cognitive work, particularly in mobile settings. Neuroergonomics research employing mobile and immobile brain imaging techniques are discussed in the following areas of physical and cognitive work: (1) physical work parameters; (2) physical fatigue; (3) vigilance and mental fatigue; (4) training and neuroadaptive systems; and (5) assessment of concurrent physical and cognitive work. Finally, the integration of brain and body measurements in investigating workload and fatigue, in the context of mobile brain/body imaging ("MoBI"), is discussed.
Background
We conducted this study to investigate how physical and cognitive ergonomic workloads would differ between robotic and laparoscopic surgeries and whether any ergonomic differences would be ...related to surgeons’ robotic surgery skill level. Our hypothesis is that the unique features in robotic surgery will demonstrate skill-related results both in substantially less physical and cognitive workload and uncompromised task performance.
Methods
Thirteen MIS surgeons were recruited for this institutional review board-approved study and divided into three groups based on their robotic surgery experiences: laparoscopy experts with no robotic experience, novices with no or little robotic experience, and robotic experts. Each participant performed six surgical training tasks using traditional laparoscopy and robotic surgery. Physical workload was assessed by using surface electromyography from eight muscles (biceps, triceps, deltoid, trapezius, flexor carpi ulnaris, extensor digitorum, thenar compartment, and erector spinae). Mental workload assessment was conducted using the NASA-TLX.
Results
The cumulative muscular workload (CMW) from the biceps and the flexor carpi ulnaris with robotic surgery was significantly lower than with laparoscopy (
p
< 0.05). Interestingly, the CMW from the trapezius was significantly higher with robotic surgery than with laparoscopy (
p
< 0.05), but this difference was only observed in laparoscopic experts (LEs) and robotic surgery novices. NASA-TLX analysis showed that both robotic surgery novices and experts expressed lower global workloads with robotic surgery than with laparoscopy, whereas LEs showed higher global workload with robotic surgery (
p
> 0.05). Robotic surgery experts and novices had significantly higher performance scores with robotic surgery than with laparoscopy (
p
< 0.05).
Conclusions
This study demonstrated that the physical and cognitive ergonomics with robotic surgery were significantly less challenging. Additionally, several ergonomic components were skill-related. Robotic experts could benefit the most from the ergonomic advantages in robotic surgery. These results emphasize the need for well-structured training and well-defined ergonomics guidelines to maximize the benefits utilizing the robotic surgery.
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