Comparison of OWAS,RULA and REBA for assessing potential work-related musculoskeletal disorders

This study compared three representative observational methods for assessing musculoskeletal loadings: Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA). The comparison was based on 209 cases of upper-body musculoskeletal disorders (MSDs) diagnosed by medical doctors. The most awkward/stressful posture in each participant's tasks was assessed using these techniques. Postural loadings were rated more highly by the RULA than by the OWAS and REBA (p < 0.01). The chi-square test and logistic regression analysis showed that only RULA grand score and action level, and REBA action level were associated with MSD work-relatedness (p < 0.01, p < 0.05, and p < 0.05, respectively). The percentage concordant values of the logistic model for the RULA grand score and action level were 52.4% and 44.8%, respectively, while the percentage concordant value for the REBA action level was 22.1%. Therefore, the RULA may be the best system for estimating the postural loads and work-relatedness of MSDs.Relevance to industryWork-related musculoskeletal disorders are the leading cause of workplace disability in the developed countries. For preventing the disorders, quantification of musculoskeletal loads is required.     

Comparison of the Ovako Working Posture Analysis System,Rapid Upper Limb Assessment,and Rapid Entire Body Assessment based on the maximum holding times

The objectives of this study were to measure the maximum holding times (MHTs) for symmetric and asymmetric body postures and to compare three representative observational methods, i.e., Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA), based on the MHTs. An experiment was performed to obtain the MHTs, wherein the independent variables were the hand position, trunk rotation angle, and external load. The hand position was defined using the hand height as the percentage of the shoulder height and the hand distance as the percentage of the arm reach. While the four independent variables including the hand height, hand distance, trunk rotation angle, and external load significantly affected the MHTs and RULA grand score at α = 0.01, only three of them (except the external load) were significant on the OWAS action category and REBA score. RULA assessed the postures tested in the experiment more stressfully than the OWAS and REBA, and the RULA grand score was more sensitive to the MHTs. In addition, the RULA grand score had larger correlation coefficients with the MHTs and other criteria for postural loads, such as whole-body discomfort, compressive force at L5/S1, and percent capables at the shoulder and trunk, than the OWAS action category and REBA score. Based on the findings of this study, it is concluded that of the three observational methods, RULA may be better for assessing postural loads under the experimental conditions.Relevance to industryWork-related musculoskeletal disorders are a major worldwide problem in industries. For preventing their development owing to multiple risk factors, it is important to quantify exposure to such risk factors.     

Comparison of ergonomic risk assessment outputs from OWAS and REBA in forestry timber harvesting

Globally, work-related (musculoskeletal disorders (MSDs) are one of the most important health problems encountered by ergonomists. Forest work, especially logging harvesting, is traditionally recognized as one of the most difficult types of physical work and has distinct characteristics. Harvesting works in forestry are composed of the following work stages: logging, skidding, and loading. This study aimed to examine risk factors of MSDs associated with different work postures during harvesting under variable external conditions by comparing work stages using the Ovako Working posture Assessment System (OWAS) and Rapid Entire Body Assessment (REBA). A statistically significant difference was observed between the two methods. While the difference in risk to the musculoskeletal system was statistically significant in different work stages using REBA, logging and skidding were assigned to the same risk level using OWAS. Easy-to-use ergonomic hand tools should be developed that are suitable for working conditions and help reduce MSD risk in forestry workers.     

Measuring the physical demands of work in hospital settings: design and implementation of an ergonomics assessment

BACKGROUND: Assessing the physical demands of the heterogeneous jobs in hospitals requires appropriate and validated assessment methodologies. METHODS: As part of an integrated assessment, we adapted Rapid Entire Body Assessment (REBA), using it in a work sampling mode facilitated by a hand-held personal digital assistant, expanding it with selected items from the UC Computer Use Checklist, and developed a scoring algorithm for ergonomics risk factors for the upper (UB) and lower body (LB). RESULTS: The inter-rater reliability kappa was 0.54 for UB and 0.66 for LB. The scoring algorithm demonstrated significant variation (ANOVA p<0.05) by occupation in anticipated directions (administrators ranked lowest; support staff ranked highest on both scores). A supplemental self-assessment measure of spinal loading correlated with high strain LB scores (r=0.30; p<0.001). CONCLUSION: We developed and validated a scoring algorithm incorporating a revised REBA schema adding computer use items, appropriate for ergonomics assessment across a range of hospital jobs.     

Risk factors for musculoskeletal injuries in airline maintenance,repair & overhaul

Aircraft maintenance workers are exposed to high injury rates, but risk exposures are difficult to measure and task contributors are difficult to identify due to the wide variety of parts and irregularity of jobs in this industry. Subjective metrics, posture assessments, and lifting analyses were collected from 235 employees from five work areas in aviation maintenance, repair and overhaul (MRO) facilities to measure ergonomic risk factors and identify task factors contributing to poor biomechanics. Nordic Musculoskeletal Questionnaire indicated that the low back was the most commonly reported region of the body experiencing aches, pain, and discomfort (41% of participants), while knees were the highest (68%) in cabin maintenance, likely due to constraints in the aircraft cabin. Rapid Entire Body Assessment (REBA) assessments showed that 57% of the jobs examined fell within the high-risk category. Causes of poor biomechanics differed by work area, e.g., overhead work was a key contributor in the engine change facility, while non-adjustable workstations were a likely contributor in cabin maintenance and engine maintenance. The under-looked cabin maintenance, engine change, and logistic jobs are the most pressing work areas in MRO that need ergonomic interventions.     

Evaluation of ergonomic working conditions among standing sewing machine operators in Sri Lanka

BackgroundStanding Sewing Machine Operators (SSMOs) are engaged in highly repetitive operations, and work while standing during their entire working hours. This leads to discomforts and Musculoskeletal Disorders (MSDs). However, there is a dearth of research in SSMOs’ working conditions.Objective: Aim of the study is to evaluate the prevalence of MSDs and related ergonomic risk factors among SSMOs in the Sri Lankan textile industry.Methods: The sample included 552 female sewing machine operators. Data were collected through self-reported questionnaires which included demographic, job-related factors and Cornell Musculoskeletal Discomfort Questionnaire [CMDQ], along with the application of validated ergonomic tools (Rapid Entire Body Assessment [REBA] and Strain Index [SI]) to assess the ergonomic risks amongst them. The inter-rater reliability test ensured the reliability among observers. An individual regression model was developed for each body parts to assess the associated risk factors.Results: The highest occurrence of musculoskeletal symptoms were in knee, foot, thigh, lower leg and lower back of SSMOs. REBA grand score (4–11) indicated that workers’ postures were at medium, high and very high risk levels necessitating evaluation to change. Moreover, SI indicated medium and high risk of upper extremity disorders. Finally, regression models revealed associated risk factors with musculoskeletal symptoms among various body parts including age, Body Mass Index (BMI), marital status, SSMO experience, job satisfaction, job stress, daily walking distance to the boarding place/factory, interest in job rotation and satisfaction with the design of sewing machine.Conclusion: The findings highlighted that the prevalence of discomfort and MSDs in the lower limbs were higher than in the upper limbs among SSMOs. The findings revealed the working conditions of SSMO and emphasised the need for ergonomic interventions to minimise the MSDs among them.Relevance to industryThe findings highlighted ergonomic risks among SSMOs and associated risk factors which will help managers and researchers better understand the working conditions of SSMOs. The identified risk factors could be considered during the implementation of standing sewing operation layouts and during the selection and allocation of new employees.     

Musculoskeletal pain in operating room nurses: Associations with quality of work life,working posture,socio-demographic and job characteristics

This cross-sectional study evaluated the association of socio-demographic and job characteristics as well as quality of work life (QWL) and working posture with the presence of musculoskeletal pain (MSP) among 144 operating room (OR) nurses in Iran. A questionnaire (including the Nordic Musculoskeletal Questionnaire [NMQ] and the QWL questionnaire) and direct observations of working postures using the Rapid Entire Body Assessment (REBA) method were used. A high prevalence of MSP, particularly in the low back (61.9%), knees (60.5%), ankles/feet (55.8%) and neck (44.9%) were found. The overall mean REBA score of 7.7 suggested that most OR nurses (with posture assessed at action levels 3 and 4) needed an immediate investigation and changes in their working habits and workstations to reduce the risk level. Work-related factors including type of operating room, work shifts (rotating), feeling pressure due to work, total QWL and its dimensions (particularly health and safety, knowledge and esteem needs) and working postures were associated with the presence of MSP in different body regions. Socio-demographic factors including gender (being female) and little or no involvement in sport/physical activity were also independently associated with the occurrence of complaints. The findings emphasise the need for multiple component ergonomic interventions involving the socio-demographic and work-related physical and psychosocial factors for prevention of MSP in this occupational group.     

Quantitative and qualitative assessment of musculoskeletal disorders and socioeconomic issues of workers of brick industry in Pakistan

Brick industry, in Pakistan, is prominent and provides job to 3.1 million people only in one province. The industry hires different percentage of workers for different stages of brick formation and these stages trigger musculoskeletal disorders (MSDs) in workers. This study identifies relation between 5 work stages and MSDs in 9 body parts and also finds socioeconomic sufferings inflicted by the industry and removal of research gap at national level. We conducted both qualitative and quantitative research. 105 men and 45 women from 15 brick kilns were selected as subject. Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA) sheets, Standard Nordic MSDs Questionnaire along with general questionnaire, still photography and video recording were used to carry out the study. About 96% workers involved in mixing & molding complained tiredness at end of day. Similarly, 90% male and 83% female staff performing spreading task suffered tiredness after their duty hours. Workers engaged in different tasks reported varying levels of pain in observed body parts. Digging and carrying jobs caused significant pain in body parts including neck, upper back, shoulders, lower back and hips. Mixing and molding emerged most dangerous activities for most of the body parts and exhibited 7 score on RULA. Furthermore, mixing and molding demonstrated high to very high risk level by showing 9 and 13 higher score on REBA, respectively. The current study divulged that all observed work tasks during manufacturing and transportation of bricks are equally dangerous for pain generation in lower back. Many socioeconomic issues like residency of workers in muddy house (83%) low monthly income (<90.3 $) of 83% workers, higher tendency of alcoholism and smoking in men, lack of health facilities and higher illiteracy rate were also identified. The enhanced musculoskeletal disorders during brick making process render the brick industry unhealthy for work. This dismal picture requires an improvement in quality of life and occupational environment of workers of the industry. Well organized duty timings, modified working posture, job rotation and preliminary training perhaps manage these miseries and the output of the brick industry may increase many fold.     

Ergonomic risk factors in glass artware industries and prevalence of musculoskeletal disorder

Glass artware manufacturing activities are highly repetitive, labor-intensive, and demand prolonged standing during the working shift. This leads to the development of musculoskeletal disorders (MSDs) symptoms among the workers. However, there is a scarce of study on the prevalence of MSDs symptoms and their associated risk factors among the glass artware workers. To address this research gap, this study aims to evaluate the prevalence of MSDs and working conditions among Indian glass artware workers. Discomfort data is collected using Cornell Musculoskeletal Discomfort Questionnaire and working posture data is collected through direct observations using Rapid Entire Body Assessment (REBA). Multiple logistic regression model is developed for each body region to study the relationship between the associated risk factors and MSDs symptoms with the help of collected data. The findings of this study are first, MSDs symptoms are highly prevalent and severe, particularly in the lower back, thigh, and foot. Second, the average REBA grand score is 7.22, which reveals the high-risk level of worker's posture while performing the task. Third, Job characteristics and individual factors are associated with MSD symptoms in multiple logistic regression models. The results highlight the prevalence and severity level of MSDs and illustrate the demand for ergonomic interventions to alleviate musculoskeletal symptoms among these working groups.Relevance to industryThis study draws attention to work-related and other associated risk factors, which would help the researchers and managers to understand the working environment of glass artware industry. These risk factors should be considered for designing and implementing ergonomic interventions to prevent and alleviate musculoskeletal discomfort among the glass artware workers.     

Intra-rater and inter-rater reliability of the rapid entire body assessment (REBA) tool

BackgroundErgonomics researchers and practitioners use many techniques to assess risk. The Rapid Entire Body Assessment (REBA) is a common tool used to facilitate the measurement and evaluation of the risks associated with working postures as a part of ergonomic workload. However, little work has been reported regarding the reliability of REBA reporting.ObjectiveThis study assesses the reliability of this commonly used tool for research and practice.MethodsThe study was conducted as part of the larger Safe Workload Ergonomic Exposure Project (SWEEP), which is a University of Minnesota research initiative for custodians. For this effort, a secondary data analysis was conducted on data collected during a study of custodians’ exposures to risks of musculoskeletal disorders. Eight observers used the REBA tool to sequentially evaluate tasks performed two times in succession by the same individual.ResultsThis study reports high intra-rater reliability (ICC = 0.925) for REBA raw scores and moderate inter-rater reliability (IRR) (Fleiss kappa = 0.54) for a categorical scoring of REBA.ConclusionA moderate amount of IRR was found, and a standardized training and calibration protocol is proposed as a potential means to improve intra- and inter-rater reliability.     

Rapid entire body assessment (REBA)

This technical note details the preliminary stage in the development of a postural analysis tool, Rapid Entire Body Assessment (REBA). REBA has been developed to fill a perceived need for a practitioner's field tool, specifically designed to be sensitive to the type of unpredictable working postures found in health care and other service industries. A team of ergonomists, physiotherapists, occupational therapists and nurses collected and individually coded over 600 postural examples to produce a new tool incorporating dynamic and static postural loading factors, human-load interface (coupling), and a new concept of a gravity-assisted upper limb position. Initial reliability for inter-observer coding shows promise but further work is needed to establish the validity of the tool.     

Physical risks of work-related musculoskeletal complaints among quarry workers in East of Iran

Quarry workers are at high risk of developing musculoskeletal complaints. The aim of this study was to evaluate the working postures and prevalence of musculoskeletal problems among quarry workers. In this cross-sectional study 78 male quarry workers were assessed using the method of Rapid Entire Body Assessment (REBA), and musculoskeletal complaints data were obtained by the Standardized Nordic Musculoskeletal questionnaire (NMQs). Results of the prevalence of musculoskeletal problems in body parts of stonemasonry workers was higher found than in the stonecutting workers. The highest prevalence rate of musculoskeletal problems in both stonemasonry and stonecutting workers was 65.7% and 54.8% respectively related to waist. The stonemasons with 62% had high level of risk and stone cutting workers with 47.6% had moderate risk level. Significant correlation was found among age, work experience, BMI, and prevalence of musculoskeletal problems. There was also a significant relationship between the wrist and lower back pain with the risk level of REBA score. The study results showed that musculoskeletal problems of workers had high prevalence and accordingly most of the work conditions and postures needed to be improved, so prioritizing the necessity of corrective actions and intervention are to be gained.     

Effectiveness of an ergonomic intervention on work-related posture and low back pain in video display terminal operators: A 3 year cross-over trial

This study investigated the effectiveness of a workstation ergonomic intervention for work-related posture and low back pain (LBP) in Video Display Terminal (VDT) workers. 100 VDT workers were selected to receive the ergonomic intervention, whereas 100 were assigned to a control group. The two groups were then crossed-over after 30 months from baseline. Follow-ups were repeated at 5, 12, and 30 months from baseline and then at 6 months following crossover. Outcomes: Work-related posture and LBP point-prevalence using the Rapid Entire Body Assessment method and a Pain Drawing, respectively. The ergonomic intervention at the workstation improved work-related posture and was effective in reducing LBP point-prevalence both in the first study period and after crossover, and these effects persisted for at least 30 months. In conclusion, our findings contribute to the evidence that individualized ergonomic interventions may be able to improve work-related posture and reduce LBP for VDT workers.     

An investigation of the reliability of Rapid Upper Limb Assessment (RULA) as a method of assessment of children's computing posture

Rapid Upper Limb Assessment (RULA) is a quick observation method of posture analysis. RULA has been used to assess children's computer-related posture, but the reliability of RULA on a paediatric population has not been established. The purpose of this study was to investigate the inter-rater and intra-rater reliability of the use of RULA with children. Video recordings of 24 school children were independently viewed by six trained raters who assessed their postures using RULA, on two separate occasions. RULA demonstrated higher intra-rater reliability than inter-rater reliability although both were moderate to good. RULA was more reliable when used for assessing the older children (8-12 years) than with the younger children (4-7 years). RULA may prove useful as part of an ergonomic assessment, but its level of reliability warrants caution for its sole use when assessing children, and in particular, younger children.     

Planning and implementation of microscope work

In modern electronics manufacturing, many of the assembly operations require the use of microscopes. This paper presents measures and suggestions that could help in relieving visual and postural fatigue in microscope work. These measures include the ergonomic design of microscope workstations as well as of microscopes themselves, process changes to minimise use of the microscope, replacement of microscope workstations with television systems, and a training programme for inexperienced operators. The main emphasis in implementing these recommendations was the ergonomic design of microscope workstations; several examples are given.     

Ergonomic contribution of ABLE exoskeleton in automotive industry

In PSA Peugeot Citroen factories, high precision requirements of workstations make them being manual. One of the main goal of the car manufacturer is to minimize the pain of workers while maintaining high efficiency of production lines. Consequently, assisting operators with an exoskeleton is a potential solution for improving ergonomics of painful workstations while respecting industrial constraints. To determine ergonomic performances of an exoskeleton, human joint angles and torques, ground reaction forces, and duration of operations are analysed for eight subjects performing a representative screwing task. Experiments were performed using ABLE upper-limb exoskeleton, developed by the French Atomic Energy Commission (CEA), which has the functionality to compensate arm and tools loads. Results show a clear reduction of the sum of the joints torques, up to 38.9%, given by ABLE supply and invite to make concrete the use of exoskeletons in car assembly lines.     

Investigation of musculoskeletal symptoms and ergonomic risk factors among female sewing machine operators in Turkey

This cross-sectional study aimed to identify the prevalence of musculoskeletal symptoms and ergonomic risks in female sewing machine operators at a textile company. The study sample comprised all female sewing machine operators in the company. The sample included 283 sewing machine operators. Data were collected through the use of the adapted Nordic Musculoskeletal Questionnaire and by direct observations via the rapid upper limb assessment (RULA) to determine ergonomic risks. RULA is a validated tool for assessment of ergonomic risks. The mean age of the women was 30.2 (SD: 8.4) and the mean number of years of employment was 13.4 (SD: 5.5). The highest prevalence rates for the women’s musculoskeletal symptoms were in the trunk (62.5%), neck (50.5%), and shoulder (50.2%). Of the women, 65% had experienced musculoskeletal pain or discomfort over the last 6 months. Pain intensity of these symptoms was assessed with a visual analogue scale. The average pain intensity of the women was found to be 3.5 (SD: 2.8). Results of the RULA scores were found to be quite high. There were no employees who received RULA scores of 1–2, which indicates acceptable postures (all scores >5). The final RULA scores of 6.9 indicate that the participants’ postures at their work stations need to be investigated immediately.

Relevance to industry

This study based on the RULA method allowed to perform a rapid and quite correct evaluation tolls for SMOs. For this research population, the research findings provided fundamental data on the prevalence of musculoskeletal symptoms and ergonomic risks among Turkish female SMOs.     

Ergonomic postural assessment using a new open-source human pose estimation technology (OpenPose)

Observational ergonomic postural assessment methods have been commonly used to evaluate the risks of musculoskeletal disorders. Researchers have proposed semi-automatic methods using Kinect, known for limitations with body occlusions and non-frontal tracking. Meanwhile, new human pose estimation methods have been actively developed, and a popular open-source technology is OpenPose. This study aims to propose the OpenPose-based system for computing joint angles and RULA/REBA scores and validate against the reference motion capture system, and compare its performance to the Kinect-based system. Recordings of 10 participants performing 12 experimental tasks under different conditions: with/without body occlusions and tracked from frontal/non-frontal views were analyzed. OpenPose showed good performance under all task conditions, whereas Kinect performed significantly worse than OpenPose especially at cases with body occlusions or non-frontal tracking. The findings suggested that OpenPose could be a promising technology to measure joint angles and conduct semi-automatic ergonomic postural assessments in the real workspace where the conditions are often non-ideal.     

Ergonomic assessment of office worker postures using 3D automated joint angle assessment

Sedentary activity and static postures are associated with work-related musculoskeletal disorders (WMSDs) and worker discomfort. Ergonomic evaluation for office workers is commonly performed by experts using tools such as the Rapid Upper Limb Assessment (RULA), but there is limited evidence suggesting sustained compliance with expert’s recommendations. Assessing postural shifts across a day and identifying poor postures would benefit from automation by means of real-time, continuous feedback. Automated postural assessment methods exist; however, they are usually based on ideal conditions that may restrict users’ postures, clothing, and hair styles, or may require unobstructed views of the participants. Using a Microsoft Kinect camera and open-source computer vision algorithms, we propose an automated ergonomic assessment algorithm to monitor office worker postures, the 3D Automated Joint Angle Assessment, 3D-AJA. The validity of the 3D-AJA was tested by comparing algorithm-calculated joint angles to the angles obtained from manual goniometry and the Kinect Software Development Kit (SDK) for 20 participants in an office space. The results of the assessment show that the 3D-AJA has mean absolute errors ranging from 5.6° ± 5.1° to 8.5° ± 8.1° for shoulder flexion, shoulder abduction, and elbow flexion relative to joint angle measurements from goniometry. Additionally, the 3D-AJA showed relatively good performance on the classification of RULA score A using a Random Forest model (micro averages F1-score = 0.759, G-mean = 0.811), even at high levels of occlusion on the subjects’ lower limbs. The results of the study provide a basis for the development of a full-body ergonomic assessment for office workers, which can support personalized behavior change and help office workers to adjust their postures, thus reducing their risks of WMSDs.