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Ergonomic interventions such as increased scheduled breaks or job rotation have been proposed to reduce upper limb muscle fatigue in repetitive low-load work. This review was performed to summarize and analyze the studies investigating the effect of job rotation and work-rest schemes, as well as, work pace, cycle time and duty cycle, on upper limb muscle fatigue. The effects of these work organization factors on subjective fatigue or discomfort were also analyzed. This review was based on relevant articles published in PubMed, Scopus and Web of Science. The studies included in this review were performed in humans and assessed muscle fatigue in upper limbs. 14 articles were included in the systematic review. Few studies were performed in a real work environment and the most common methods used to assess muscle fatigue were surface electromyography (EMG). No consistent results were found related to the effects of job rotation on muscle activity and subjective measurements of fatigue. Rest breaks had some positive effects, particularly in perceived discomfort. The increase in work pace reveals a higher muscular load in specific muscles. The duration of experiments and characteristics of participants appear to be the factors that most have influenced the results. Future research should be focused on the improvement of the experimental protocols and instrumentation, in order to the outcomes represent adequately the actual working conditions. Relevance to industryIntroducing more physical workload variation in low-load repetitive work is considered an effective ergonomic intervention against muscle fatigue and musculoskeletal disorders in industry. Results will be useful to identify the need of future research, which will eventually lead to the adoption of best industrial work practices according to the workers capabilities.

More studies are needed to clarify the relation between work and WRMSD's, especially prospective investigations from different economic sectors and work activities, but with similar, reproducible and comparable methodologies.

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<p>Cuando se ejecuta una tarea, puede observarse actividad cerebral através de las ondas eléctricas en diversas bandas de frecuencia. Los principales son las ondas Alfa, Beta, Theta y Delta. Según algunos autores, las ondas Beta y Alfa están relacionados con la capacidad cognitiva y, su presencia y evolución, la aparición y evolución, con el estado de alerta de un individuo. En este estudio, la intención fue evaluar cómo actividad cerebral está directamente influenciada por la temperatura y humedad mientras realiza una tarea. Por lo tanto, se llevaron a cabo un conjunto de pruebas de laboratorio para simular trabajo sedentario en dos diferentes ambientes térmicos: 18 ºC - 40% RH (en frío) y 35 ºC - 80% RH (caliente). En el ambiente térmico caliente, la oscilación de amplitud de las ondas alfa sugiere una alternancia entre periodos de cansancio con los períodos en que aumenta la concentración. Con respecto a las ondas Beta en el ambiente térmico frío, la mayoría de la actividad Beta es típicamente mayor que el verificado en el ambiente térmico caliente.</p>

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The emergence of physiological monitoring technologies has produced exceptional opportunities for real-time collection and analysis of workers’ physiological information. To benefit from these safety and health prognostic opportunities, research efforts have explored the applicability of these devices to control workers’ wellbeing levels during occupational activities. A systematic review is proposed to summarise up-to-date progress in applying physiological monitoring systems for occupational groups. Adhering with the PRISMA Statement, five databases were searched from 2014 to 2021, and 12 keywords were combined, concluding with the selection of 38 articles. Sources of risk of bias were assessed regarding randomisation procedures, selective outcome reporting and generalisability of results. Assessment procedures involving non-invasive methods applied with health and safety-related goals were filtered. Working-age participants from homogeneous occupational groups were selected, with these groups primarily including firefighters and construction workers. Research objectives were mainly directed to assess heat stress and physiological workload demands. Heart rate related variables, thermal responses and motion tracking through accelerometry were the most common approaches. Overall, wearable sensors proved to be valid tools for assessing physiological status in working environments. Future research should focus on conducting sensor fusion assessments, engaging wearables in real-time evaluation methods and giving continuous feedback to workers and practitioners.