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Posted by Sadia Waseem
According to a report published by the Bureau of Labor Statistics, nearly 1 million people take time away from work annually to treat and recover from musculoskeletal pain. Musculoskeletal Disorders or MSDs affect body movement or musculoskeletal system (i.e., muscles, tendons, ligaments, nerves, discs, blood vessels, etc.). Factory workers usually face various problems due to MSDs, such as loss of function due to overexertion or repetitive motion either in the low back or upper extremities.
The following report further state that these conditions not only lead to physical discomfort but also causes reduces productivity and increases costs of manufacturing. Estimated workers’ compensation costs associated with these lost workdays range from $13 to $20 billion annually. However, when you include indirect costs such as lost wages, productivity, and tax revenue estimates go as high as $45 to $54 billion annually.
Thankfully, today there are ergonomics assessment tools like REBA (Rapid Entire Body Assessment) through which you can use to mitigate ergonomics risks and ultimately reduce the incidence of MSDs among workers and associated costs.
REBA (Rapid Entire Body Assessment) is a type of ergonomics assessment tool designed to measure the risk of musculoskeletal disorders (MSDs) across possible body segments of workers. REBA was first developed by Sue Hignett and Lynn Mc Atamney at Nottingham Hospital (The United Kingdom) as per paper published in 2000. It allows you to jointly analyze the postures of the upper limbs (arm, forearm, wrist), trunk, neck and lower extremities. In addition, it discriminates the type of grip and muscle activity performed.
The aim of the REBA Assessment is to:
REBA assessments offer several key benefits for both employers and employees, including:
1. Reduces Cost
MSDs can be expensive to treat and involve doctor visits, physical therapy, medications, and even surgery. Moreover, MSDs are a leading cause of workers’ compensation claims. REBA significantly reduces MSDs, and therefore reduces and eliminates all the costs associated with it.
2. Easy to Implement
The assessment is relatively quick and easy to conduct, requiring minimal training and equipment (often just a pen and paper). Moreover, today there are AI-powered software that make it even easier. All you need is a camera to record the process and enter into the software and the software does all the calculations.
3. Proactive Approach
REBA is a proactive tool. Instead of waiting for injuries to occur, it allows you to identify and address potential problems before they become serious
4. Instant Identification of High-Risk Areas
One of the significant advantages of REBA assessment is that it highlights the most urgent risks through score, which helps prioritize interventions and immediately gives you an idea of what issues you need to address first.
REBA assessment analyzes risks associated with neck, trunk, wrist upper arm and lower arm through the different body postures. It basically assigns the score to different body postures when it deviates from the neutral position. The higher the score, the bigger the risk associated with it. Based on the risk score, it prioritizes the issues that need immediate intervention
Figure 1: Distribution of REBA Score
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In REBA Assessment body parts are divided into two groups:
Group A includes:
And Group B consists of:
Understanding the score for different body parts:
Trunk: The trunk score is based on the position and movements of an operator’s trunk. For the neutral posture, the score is 1 and for 0–20-degree fluctuation the score is 2. If the flexion is higher than 60-degree, the score is 3 and 1 is added when there is a twisting and side bending movement.
Figure 2: Scoring system for Trunk
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Neck: The neck score focuses on the angles of flexion, extension, and lateral bending. The score is 1 for 0–20-degree deviation, 2 for more than 20-degree deviation with additional point for twisting or bending of the neck.
Figure 3: Scoring system for Neck
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Leg: If the operator is in standing or sitting position with equal weight distribution for each leg, then the score is one. However, if the weight is on one leg, then the score is two. Also, 1 is added to the score if the knees are bending between 30 to 60 and 2 is added for more than 60 degrees bending.
Figure 4: Scoring system for Legs
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Upper arm: The scores for the upper arm range from 1 to 4, with 1 for 20-degree extension from the neutral position and 4 for more than 90-degree flexion. The scores increase when the arm is abducted, rotated and the shoulders are raised.
Figure 5: Scoring system for Upper Arms
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Lower arm: The lower arm is scored 1 for 60-100-degree flexion and 2 for more than 100-degree flexion.
Figure 6: Scoring system for Lower Arms
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Wrist: The extension of the wrist to 15-degree is considered safe and scored 1. In case, there is a more than 15-degree extension, the score rises to 2. An additional score is added for deviation and twisting.
Figure 7: Scoring system for Wrist
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Assigning Final Scores:
The final scores are assigned according to following score sheet:
Figure 8: REBA Score Sheet
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Figure 9: REBA Assessment Worksheet
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One way to conduct REBA assessment is through observation and manual data entry. However, it is subjective and prone to error. The second way is to use software such as Kaizen Copilot that makes the job easier.
Kaizen Copilot is an AI-powered continuous improvement software that significantly improves the productivity of industrial engineers. The software combines advanced AI algorithms and computer vision to eliminate most of manual tasks required in continuous improvement projects.
The software comes with a comprehensive ergonomics suite that allows users to employ several methods such as REBA, Snook tables, NIOSH Lifting equation to ensure and improve current workplace safety aspects.
Kaizen Copilot significantly simplifies any ergonomic analysis. All you need to do is record a video and the software takes care of the rest.
Performing REBA Assessment with Kaizen Copilot
Following are the detailed steps to effectively perform REBA assessment using Kaizen Copilot:
I. Prerequisites for Performing a REBA Assessment
Special feature: You can also manually add the posture that you think are at high risk and need attention.
II. In-Depth Analysis and Final Results:
Once you have identified all the postures along with the interval, enter the following parameters to get an in-depth analysis:
Coupling: If the object handling is good, the score is zero and as the handling becomes difficult or awkward, the score increases.
Activity score: The activity score is static if the operator is doing the same job for 1 to 2 minutes. In the repetitive option, the worker is working on the same type of unit every 30 seconds. During rapid changes, the operator changes position rapidly from one riskier position to another one.
Force/Load: The force/load section remains 0 if the operator is not handling any sort of load or weight, and it increases where there is any load handling involved during the operation.
After detecting all the high-risks posture, and manually entering all the parameters, go to generate results. This will show the results in three different forms.
I. Deeper Posture Analysis: It shows the visual representation of the body skeleton along with the color-coded visuals that highlight high risk, medium risk, and low risk for each limb. Red means the risk is high, yellow indicates the medium risk, and green shows risk-free areas. You can identify high REBA score areas for each posture that can lead to MSDs among workers.
Figure 10: An example of Deeper Posture Analysis Result from Kaizen Copilot
II. Time-Based Analysis: Time-based analysis is an assessment of the entire video. The bar of cycle assessment shows the acceptable job in green color, while red typically indicates a high-risk area that needs immediate attention. Apart from this, it identifies the riskier body segment along with the total percentage for which it is not in a safe position.
Figure 11: An example of Time-Based Analysis Result from Kaizen Copilot
III. Body Segment Analysis: The line chart in body segment analysis indicates the risk of occurrence for different parts of the body from the total duration. You can choose the body segment for which you want to get deeper insights. The analytics show risks of occurrence for the particular body type and the total duration for which a worker will be exposed to these risks. Average duration means each activity’s risk time and recovery time indicates the mean time between each risk activity. The red dotted lines show that below-the-line activities are safe while the upper ones are unsafe.
Figure 12: An example of Body Posture Analysis Result from Kaizen Copilot
After in-depth analysis you can generate a detailed report that shows the overall assessment charts limb assessment chart, and areas of risk for each posture. You can also download the report and use it to minimize or reduce the chances of MSD among workers.
The results obtained from the REBA assessment can be useful to improve workplace ergonomics and reduce the likelihood of MSDS among workers. Here is how you can effectively utilize the results:
The limitations associated with REBA assessment are:
1. Individual Postures:
REBA is focused on the analysis of individual postures rather than a sequence or set of postures. It may be difficult to work with the tasks that have a complex set of actions.
2. Limited Scope:
REBA evaluates physical risks associated with postures, forces, and movements, but it does not include other factors such as cognitive workload, environmental conditions, etc.
3. Measurement of Effort Intensity:
It takes into account the intensity of effort for different tasks, without considering the duration of exposure or frequency of exposure throughout the day.
Overall, REBA assessment is the ultimate solution for addressing ergonomics-related issue in your workplace. It can prove to be a game-changer for enhancing your employee safety and productivity. REBA assists you in effectively and economically reducing the risks of musculoskeletal disorders (MSDs) by recognizing high-risk postures and offering actionable insights. With its simple implementation along with minimal equipment and insightful results, REBA assessment enables organizations to establish a healthier work environment. Book a free demo now from our website to learn more about this tool and boost your operational performance.
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