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In the search to enhance ergonomic risk assessments for upper limb work-related activities, this study introduced and validated the efficiency of an inertial motion capture system, paired with a specialized platform that digitalized the OCRA index. Conducted in a semi-controlled environment, the proposed methodology was compared to traditional risk classification techniques using both inertial and optical motion capture systems. The inertial method encompassed 18 units in a Bluetooth Low Energy tree topology network for activity recording, subsequently analyzed for risk using the platform. Principal outcomes emphasized the optical system's preeminence, aligning closely with the conventional technique. The optical system's superiority was further evident in its alignment with the traditional method. Meanwhile, the inertial system followed closely, with an error margin of just ±0.098 compared to the optical system. Risk classification was consistent across all systems. The inertial system demonstrated strong performance metrics, achieving F1-scores of 0.97 and 1 for "risk" and "no risk" classifications, respectively. Its distinct advantage of portability was reinforced by participants' feedback on its user-friendliness. The results highlight the inertial system's potential, mirroring the precision of both traditional and optical methods and achieving a 65% reduction in risk assessment time. This advancement mitigates the need for intricate video setups, emphasizing its potential in ergonomic assessments.

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Brazil is the leader in poultry meat exports, in which most products are in the form of cuts. This study analyzed the exertion perception of poultry slaughterhouses workers when performing cutting tasks, as well as the influence of knife sharpness on the risk of developing musculoskeletal disorders by Occupational Repetitive Action (OCRA) method. Participants (n = 101) from three slaughterhouses were asked to rate their perceived exertion on the Borg scale during the cutting task when the knife was well and poorly sharpened. The OCRA results showed that the score for cutting with a dull knife was greater (43.57 ± 13.51) than with a sharp knife (23.79 ± 3.10) (p < 0.001). Consequently, there was a significant increase in the risk level of acquiring upper-limb work-related musculoskeletal disorders (UL-WMSD) by using a "poorly sharpened" knife (29%; p < 0.001; Borg scale 2-8). Thus, maintaining well-sharpened knives for optimal performance of the cutting task (fewer technical actions) is suggested, as well as including knife sharpening in the standard operating procedure to reduce musculoskeletal disorders.

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Risk analysis is one of the main tools for preventing the occurrence of Work-Related Musculoskeletal Disorders. New methods of risk analysis should seek to be more agile and simplified, encouraging them to be widely applied in work environments. This paper aimed to develop a rapid tool for assessing the risk of developing Work-Related Musculoskeletal Disorders (WMSDs) arising from repetitive actions of the upper limbs, while using a thermographic camera to measure skin temperature variation. A workstation was developed in an environmentally controlled laboratory, representing the five levels of risk presented by the Occupational Repetitive Actions Index (OCRA) Index, which were performed by 32 participants for 20 min. each level. There was a significant change in forearm skin temperature at all risk levels (p < 0.001), with a positive linear correlation (r = 0.658 and p < 0.001), which led the authors to perform linear regression analysis for the forearm region. The Predicted OCRA Index calculation equation was successfully developed (R = 0.767 and R² = 0.588), while using as independent variables: air temperature and temperature variation of the forearm skin. The Predicted OCRA Index can be applied as a screening tool for large numbers of workers in the same company or sector, due to its speed of application and the determination of risk level, but it does not replace the original OCRA Index.

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Resumen Los desórdenes musculo esqueléticos (DME) son la nueva epidemia de enfermedades crónicas, son multifactoriales y afectan los diferentes sectores productivos. Aunque se encuentran múltiples instrumentos para la evaluación de la carga estática y dinámica, el OCRA (Occupational Repetitive Action) parece ser una opción atractiva. Objetivo. Realizar una búsqueda de literatura sobre el uso del método OCRA y DME en trabajadores de diversos sectores productivos (20072018). Materiales y métodos. Una revisión de literatura (siguiendo la declaración PRISMA) de estudios que evaluaran el nivel de riesgo biomecánico (OCRA) y DME en las bases de datos Scielo, Science Direct, Scopus, ProQuest, Gale, PubMed, Lilacs y Ebsco fue realizada, 7 estudios cumplieron con los criterios de selección; la mayoría son cuantitativos (corte transversal). Resultados. El 79% de las condiciones relacionadas con la tarea requieren exigencia física e implican movimientos repetitivos (jardinería y floricultores); la aparición de DME en espalda alta-baja, extremidades superiores e inferiores, los cuales se generan por la frecuencia de las actividades realizadas (producción de calzado); además, "riesgos muy alto" de desarrollar DME (industria del salmón) y un índice medio (OCRA) por movimientos repetitivos que requiere cuidado especial (línea de Ensamblaje en U) fueron encontrados. Conclusiones. La revisión arrojo el uso limitado del método OCRA para la detección de DME en trabajadores de diferentes sectores; y este método puede ser usado para la detección del riesgo biomecánico.

Abstract Musculoskeletal disorders (MSD) are the new epidemic of chronic diseases, are multifactorial and affect to different productive sectors. Although there are multiple tools for the evaluation of static and dynamic load, OCRA (Occupational Repetitive Action) seems to be an attractive option. Objective. To conduct a literature search on the use of the OCRA and DME method in workers of various productive sectors (2007-2018). Materials and methods. A literature review (following the PRISMA statement) of studies assessing the level of biomechanical risk (OCRA) and the prevalence of DME in the Scielo, Science Direct, Scopus, ProQuest, Gale, PubMed, Lilacs and Ebsco databases was performed, 7 studies met the selection criteria; Most are quantitative. Results. 79% of the conditions related to the task require physical demands and involve repetitive movements (gardening and flower growers); the production of DME in upper-lower back, upper and lower extremities, wich are generated by the frequency of the activities in the footwear production; In addition, "very high risks" of developing DME (salmon industry) and a medium index (OCRA) for repetitive movements that require special care (U-Assembly line) were found. Conclusions. The review showed the limited use of the OCRA method for the detection of SMD in workers from different sectors; and this method can be used for the detection of biomechanical risk.

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O processo de seleção dos métodos observacionais de avaliação do risco de LER/DORT é complexo, mas fundamental para a gestão do risco. Em Setúbal, no período de 2004 a 2005, numa empresa portuguesa da indústria automobilística, onde a avaliação do risco foi previamente efetuada, reaplicou-se o método OCRA checklist (avaliação do risco de LER/DORT ao nível dos membros superiores) em postos de trabalho (n=152) montagem final e pintura classificados de risco moderado/elevado (OCRA ?16,5). Nas situações em que se reconfirmou a presença de risco (n=71), aplicaram-se três outros métodos: RULA, SI e HAL. Registraram-se sequências em vídeo da atividade de trabalho para avaliar a validade preditiva dos métodos. Revelam-se divergências entre os métodos na classificação dos postos de trabalho de risco elevado: OCRA 34 postos; HAL 35 postos; SI 31 postos; RULA 7 postos. A análise do efeito de cada variável independente (fator de risco) nos scores finais dos métodos (regressão linear multivariada) revela distintos contributos e processos de ponderação/avaliação do risco de LER/DORT. A análise dos registros em vídeo evidencia diversas validades preditivas relativamente aos fatores de risco integrantes dos métodos aplicados. Os resultados indicam a necessidade de uma seleção do método de avaliação do risco de LER/DORT adequada a cada situação (real) de trabalho, baseada no maior conhecimento dos métodos.

The process for selecting observational methods for evaluating work-related upper limb musucloskeletal disorders (WRULMSDs) is complex, but essential to risk management. In a Portuguese automotive industry plant (Setúbal, 2004-05), where all jobs had been previously analyzed, OCRA checklist was reapplied (final assembling and painting) in workstations (n=152) classified as moderate/ high risk (score 16.5 OCRA). In all risk confirmed cases (n=71) three other methods were applied: RULA, SI, and HAL. Sequences of working activities were recorded on video to estimate the predictive validity of the methods. The results show differences in the final scores of the methods in the same workstations: OCRA reveals 34 workplaces with high risk; SI only ranked 31 positions with high risk; HAL has 35 high risk workplaces, and RULA only 7. Analysis of the effect of each independent variable (risk factor) in the final scores of the methods, based on linear regression analysis, reveals different contributions and, consequently, different ways of assessing WRULMSD risk. The video analysis also highlights different predictive validities for the risk factors in each method. These results indicate the need to select the appropriate WRULMSD risk assessment instrument adequate to each real work situation.

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