Systematic Comparison of OWAS, RULA, and REBA Based on a Literature Review

This study aimed to systematically compare three representative observational methods for assessing musculoskeletal loadings and their association with musculoskeletal disorders (MSDs): Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA). The comparison was based on a literature review without time limitations and was conducted on various factors related to observational methods. The comparisons showed that although it has a significant limitation of comprising only two classifications for the leg postures, (1) the RULA is the most frequently used method among the three techniques; (2) many studies adopted the RULA even in evaluation of unstable lower limb postures; (3) the RULA assessed postural loads as higher risk levels in most studies reviewed in this research; (4) the intra- and inter-reliabilities for the RULA were not low; and (5) the risk levels assessed by the RULA were more significantly associated with postural load criteria such as discomfort, MHTs and % capable at the trunk, and MSDs.

New Challenges Regarding the Intervention of Musculoskeletal Risk in Truck Service Garages

Background: The automotive industry is heavily affected by sick leaves caused by the handling of loads and using postures that produce musculoskeletal disorders. Research is needed to analyse their causes and find possible solutions to eliminate or mitigate these risks. Objective: Our objective was to analyse the level of musculoskeletal risk in the different work tasks performed by truck and bus mechanics. Our intention is also to analyse whether postural training and feedback can help reduce risk. Methods: The rapid entire body assessment (REBA) was used to assess the postures performed by 35 mechanics from eight branches throughout Spain. The participants were subsequently divided randomly into two groups (experimental group and control group). The experimental group (EG) was given training and feedback on their postures and the control group (CG) was not offered any type of intervention. A few months after the initial assessment, their postural load in the usual tasks was re-evaluated. Results: An overall average REBA Score: 10.49 ± 1.33. The main risk was found in the trunk and arms with sustained above-the-head postures. EG’s second results are significantly improved compared to the first (p = 0.026 *). Conclusions: These jobs have a high-risk level of musculoskeletal disorders. The course of action presented with postural training and feedback has shown satisfactory results. Nevertheless, given the size of the sample, further research will be needed to delve deeper into this possibility as a future line of intervention.

De Re Metallica: An Early Ergonomics Lesson Applied to Machine Design in the Renaissance

The Renaissance treatise De Re Metallica (Georgius Agricola, 1556) is one of the first works that deals in detail with the state of the art of metal mining, compiling the main techniques and mechanical devices used in this industrial activity at that time. An advanced knowledge of the human–machine set is observed in this treatise, from a mechanical and ergonomics point of view. The main objective of this work is to carry out an ergonomics analysis of one of the mechanical devices collected in the sixth book of this treatise. It is intended to show that there was a certain concern for ergonomics in the Renaissance, long before the first appearance of this concept. Specifically, a mine water extraction pump, powered by three different systems, is analyzed. Current ergonomics assessment methods have been used to perform this comparative analysis. The postural load has been assessed by the rapid upper limb assessment (RULA) and the rapid entire body assessment (REBA). The Check List OCRA (occupational repetitive action) has been used to perform the analysis of repetitive movements. The results have shown an evolution of the machine, not only on a mechanical level, but also in movements, postures, and safety of the operator for the three methods applied. It is, therefore, an example of practical and real ergonomics applied to machine design dating from the 16th century. In addition, this work may be a very interesting tool for teaching, since it allows showing examples of ergonomics in productive areas related to historical context.

. Reflection of individual typological properties in the tremorogram (Predicting the indicators of Rusalov’s test according to the indicators of the tremorogram)

Rationale for choosing. An increase in physiological tremor (Tr) in emotionally saturated situations is reflected not only in fiction, but also in scientific literature. In other words, tremors and emotional responses are interconnected. Purpose. To investigate the reflection of individual-typological properties in a tremorogram using V. M. Rusalov’s mathematical modeling. Material and methods. Tr was recorded using a linear transducer. Tr was recorded under postural load (arms extended forward). The sensor was alternately placed on the outstretched right and left arms in front of oneself, under conditions of “eyes open” (operative rest). The analysis of the tremorogram (TrG) files was carried out after the end of the study using the "Analist - 2" software according to the half - period analysis algorithm. To study the individual psychological characteristics of the personality, we used the method of determining the properties of the temperament by V.M. Rusalov. Each of the many indicators of Rusalov’s test selected in the analysis was considered as a target feature (Y-s), and the amplitudes and frequencies of TrG were considered as influencing variables (sets of X - s) and multiple linear regression equations of the form were built: The parameters of the amplitude and frequency of EEG rhythms were used as Xs. Own research. In multiple regression analysis of the influence of TrG indices of the right hand on the indices of Rusalov’s test, 12 statistically significant regression coefficients were determined, and 11 statistically significant regression coefficients for the left hand. After obtaining the diagnostic equations of multiple linear regression, describing the influence of TrG indicators on the indicators of Rusalov’s test, an attempt was made, using these equations, to obtain the indicators of Rusalov’s test, using the tremor indicators. On average, the% discrepancy between the determined and predicted indicators was 97.42% for the right hand, and 101.98 for the left. Conclusions. 1. With the use of diagnostic equation, it was possible to predict the indicators of psychological testing according to Rusalov’s test by the indicators of tremor of the right and left hands.2. Influence of Rusalov’s test indicators on TrG indicators were less in modulus than the influence of TrG indicators on the indicators of Rusalov’s test, i.e. did not participate in the control of the mechanisms of TrG generation.3. The results obtained indicate that tremor indicators contain information about the subject-activity and communicative aspects of temperament according to V. M. Rusalov.

Study on the Associations of Individual and Work-Related Factors with Low Back Pain among Manufacturing Workers Based on Logistic Regression and Structural Equation Model

Work-related musculoskeletal injuries are one of the major occupational health issues of the workers, especially low back pain (LBP). The aim of this study was to survey the prevalence of LBP among manufacturing workers and to identify associations of individual and work-related factors with LBP. A cross-sectional questionnaire study was performed with 1173 participating manufacturing workers. The questionnaire included individual factors, psychosocial and physical exposures, and musculoskeletal discomfort. It was analyzed by logistic regression and structural equation modeling (SEM). The 1-year prevalence of LBP among Chinese manufacturing workers was 33.6%. Logistic regression analysis showed that job tenure, awkward postures, vibration and job demand were positively—while social support and job control were negatively associated with LBP (p < 0.05). The SEM results indicated that, as shown in other studies, job types, job tenure, postural load, high job demand, low job control and vibration were directly associated with LBP, but also that job types, high job demand, low social support and vibration may have indirect effects on LBP—mediated by postural load.

Using Electromyography to Assess Postural Load in Dentistry: A Literature Review

This study sought to perform a review of the literature on the use of electromyography to assess postural load in dental work. The literature used in this review was obtained from databases and only articles published published between 1991 and 2019 were considered. The main keywords were “electromyography,” "working posture”, “ergonomics” and “muscle activity”. Each abstract was read to determine whether the information in the article included discussions on the use of electromyography to assess postural load in dental work (n=27). It was found that electromyography is beneficial to assess the influence of different devices used in dental work, however, as it has limitations, researchers must be aware of them to seek alternatives to circumvent them.

Prevalence of Musculoskeletal Disorders among Stone Polishing Workers using Stone Polishing Devices in Unorganized Sector of Guwahati (India)

Stone polishing is one of the prominent informal sector in India (and world as well), where a large number of stone polisher works for long duration. Stone polishing workers manually operate the polishing machine either in standing or sitting position to carry out polishing activities, and are quite prone to various MSDs (repetitive strain induced) and thereby injuries and accidents. The present research therefore intends to explore the occurrences of WMSDs among the stone-polishing workers, and with utmost attempt to put forward some recommendations regarding corrective measures. Thirty (30) male stone polishing workers were selected from the Guwahati city of Assam. A comprehensive study on discomfort feeling was carried out by the modified Nordic questionnaire which considered the information about work nature and job stress. Rapid Entire Body Assessment (REBA) method was followed to evaluate whole body postural load and risks associated with the job. The finding of the study contributes to the understanding of the working conditions of the stone polishing workers and their physical discomforts at various body parts (mainly the lower back, knees and shoulder) due to awkward posture, repetitive motion, force exertion and sustained load handling during polishing activities. To overcome the problem arisen from aforesaid ergonomic stressors associated with stone-polishing work, ergonomic design intervention pertaining to modification of the equipment / hand tool like handle design, easy manoeuvrability, avoiding hand-holding of weight etc. have been proposed

Assessment of Muscular Activity and Postural Load During Coffee Harvesting Activities – A Case Study

Objective: The goal of this case study was to analyze and evaluate the posture, force and repetitive movement risks associated with manual coffee harvesting activities. Materials and Methods: A self-discomfort report was administered to 28 participants, of whom 4 volunteered for an evaluation of postural load on muscular activity using electromyography and electrogoniometry. Eight upper limb muscles and the kinematics of the wrist and upper arm of the dominant arm were assessed. Results: The results of the self-discomfort report showed a greater demand, from the harvester’s perception, in areas such as the back, lower back, knees and feet during a period of one week of work. The outcomes of the muscular activity assessment showed that the extensor carpi ulnaris (ECR) was the muscle with the highest demand during the assessment. The dynamic activity of the muscle exceeded 20% of the maximum voluntary contraction (MVC), which classifies coffee harvesting as a threatening activity. The postural load on the body segments revealed that wrist deviation was critical due to an abnormal range of the wrists during the activity. Conclusions: It is necessary to improve the working conditions of the coffee harvesters.