RULA (Rapid Upper Limb Assessment) is an ergonomic assessment tool that scores the risk of upper-limb musculoskeletal disorders from a worker’s posture. Published by Lynn McAtamney and Nigel Corlett in 1993, it scores the upper arms, lower arms, wrists, neck, trunk and legs on a one-page worksheet, adds muscle use and force, and gives a RULA score from 1 to 7.
This guide walks through the RULA worksheet step by step with a worked example, explains what each RULA score means, and shows how one job went from a RULA score of 7 to 1. Want to skip the math? Our free RULA calculator follows the same 15 steps as this guide and works out the score for you.
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What is RULA?
The Rapid Upper Limb Assessment (RULA) was developed to “rapidly” evaluate the exposure of individual workers to ergonomic risk factors associated with upper extremity MSDs. It considers the biomechanical and postural load requirements of job tasks and demands on the neck, trunk and upper extremities.
View full size image or download the RULA worksheet (PDF)
A single-page worksheet (above) is used to score the body posture, muscle use and forceful exertions for the job task being evaluated.
What RULA was designed to do
- To provide a method of screening a working population to assess exposure to significant risk of work-related upper extremity disorders.
- To identify the muscular effort which is associated with working postures and excessive forces while performing static or repetitive work, and which may contribute to muscle fatigue.
- To provide a simple scoring method with an action level output that gives an indication of urgency.
- To provide a user-friendly assessment tool that requires minimal time, effort and equipment.
RULA limitations
- It does not consider the duration of the task, the available recovery time or hand-arm vibration.
- It assesses one employee’s worst-case posture at one point in time, so you need to choose representative postures.
- It requires separate assessments of the right and left sides of the body, although in most cases you will be able to quickly tell which side has the greatest exposure to MSD risk.
RULA scores and action levels
The output of a RULA assessment is the final RULA score: a single number from 1 to 7 that represents the level of MSD risk for the job task being evaluated. Each score falls into one of four action levels.
| RULA score | Action level | What it means |
|---|---|---|
| 1 to 2 | 1 | Acceptable posture |
| 3 to 4 | 2 | Further investigation, change may be needed |
| 5 to 6 | 3 | Further investigation, change soon |
| 7 | 4 | Investigate and implement change |
ErgoPlus also reports a risk index, which is the RULA score divided by 3. The design goal is a risk index of 1.0 or lower, which is a RULA score of 3 or lower.
RULA calculator and software
You can score RULA by hand with the worksheet, or let a calculator do the table lookups for you:
- Free RULA calculator: pick the posture pictures for each step and watch the RULA score, action level and risk index update as you go. Print the result or save it as a PDF.
- RULA software: the RULA calculator in ErgoPlus Industrial saves every assessment, so you can compare jobs, share reports and track improvements across worksites.
How to do a RULA assessment
Get ready
The evaluator should prepare for the assessment by interviewing the worker being evaluated to gain an understanding of the job tasks, and by observing the worker’s movements and postures during several work cycles. Selection of the postures to be evaluated should be based on 1) the most difficult postures and work tasks (determined during worker interview and initial observation), 2) the posture sustained for the longest period of time, or 3) the posture where the highest force loads occur.
The RULA can be conducted quickly, so multiple positions and tasks within the work cycle can usually be evaluated without significant time and effort. When using RULA, only the right or left side is assessed at a time. After interviewing and observing the worker, the evaluator can determine if only one arm should be evaluated or if an assessment is needed for both sides.
Measure the body angles
The RULA assessment requires that you determine postural angles of six different body positions. In most cases, you will be able to determine the body position angle in the field as you observe the task. However, we find that it’s very helpful to take pictures or video of the task being performed from several angles if possible. You can then display the pictures on your computer monitor and use a goniometer (as pictured on left) or an overlaid transparent protractor image (as pictured on right) to measure the body segment angles. These methods are both very quick and easy and will give you the assurance that you’ve obtained the correct body position angles for the assessment.
RULA example, step by step
In this example, a worker installs an access plate inside a large metal can with a pneumatic screwdriver. Follow along with the worksheet, or open this example in the RULA calculator.
Arm and wrist analysis
Step 1: Upper arm
The upper arm score will be between 1-6. The score is based on the degree of shoulder flexion or extension, along with any adjustment for the shoulder being raised and/or abducted. Shoulder flexion is defined as anterior movement of the upper arm in the sagittal plane (forward reaching). Shoulder extension is defined as posterior movement of the upper arm in the sagittal plane (backward reaching). Upper arm (shoulder) elevation and abduction are possible adjustments that may apply. Also note the scoring adjustment (-1) that is used if the worker’s shoulder is supported or the worker is forward leaning in such a way that gravity assists the shoulder position.
In this example, the shoulder is flexed slightly less than 90 degrees for a score of +3, with an upper arm adjustment (+1) selected for shoulder abduction, for an upper arm score of 4.
Step 2: Lower arm
The lower arm score will be between 1-3. The score is based on the degree of elbow flexion or bending. Select the lower arm adjustment if either lower arm is working across the midline or to the outside of the body.
In this example, the elbow is flexed slightly less than 60 degrees for a score of +2. There is no adjustment for the arm working across the midline.
Step 3: Wrist
The wrist score will be 1-4. The score is based on the degree of wrist flexion or extension, along with a potential adjustment of +1 if wrist deviation is required.
In this example, the wrist is flexed greater than 15 degrees for a score of +3 and the wrist is deviated significantly, so the wrist adjustment (+1) is selected, for a wrist score of 4.
Step 4: Wrist twist
Select the wrist twist score from the degree of forearm pronation or supination: +1 if the wrist is twisted in the mid-range, or +2 if it is twisted at or near the end of range. Pronation is defined as rotation of the hand or forearm from a neutral (thumb up) position so that the surface of the palm is facing downward. Typical range of motion for pronation is 80-90 degrees. Supination is defined as rotation of the hand or forearm from a neutral (thumb up or handshake) position so that the surface of the palm is facing upward. Typical range of motion for supination is 70-80 degrees.
In this example, the wrist is twisted in the mid-range (+1).
Step 5: Table A posture score. Look up the upper arm (4), lower arm (2), wrist (4) and wrist twist (1) scores in Table A on the worksheet. In this example, the Table A posture score is 5.
Arm and wrist muscle use and force/load
Step 6: Muscle use. Add +1 if the posture is mainly static (held for longer than 1 minute) or the action is repeated 4 times per minute or more. If neither applies, the muscle use score is 0.
Step 7: Force/load. Choose one of the following:
- Less than 4.4 lb (2 kg), intermittent: +0
- 4.4 to 22 lb (2 to 10 kg), intermittent: +1
- 4.4 to 22 lb (2 to 10 kg), static or repeated: +2
- More than 22 lb (10 kg), or repeated loads or shocks: +3
In this example, the muscle use score is 0 and the load is 4.4 to 22 lb, static or repeated (+2).
Step 8: Wrist and arm score. Add the Table A posture score, the muscle use score and the force/load score: 5 + 0 + 2 = 7. This is the row to use in Table C.
Neck, trunk and leg analysis
Step 9: Neck
The neck position score will be between 1-6. The score is based on the degree of neck flexion or extension, along with any adjustment for neck twisting or side bending (lateral flexion). Neck flexion is movement of the chin towards the chest from a neutral neck position. Neck extension is moving the chin away from the chest (backwards) from a neutral neck position. Experts in biomechanics use a variety of landmarks and methods to define the neutral position (or the zero point between flexion and extension) of the neck. To keep it really simple, I would define neutral as the posture of the head/neck when the trunk of the body is erect (sitting or standing up straight) and looking at a visual target directly ahead at eye level.
In this example, the neck position was determined to be between 10 – 20 degrees (+2). In addition, side bending of the neck was observed (+1), for a neck score of 3.
Step 10: Trunk
The trunk position score will be between 1-6. The score is based on the degree of trunk flexion or extension, along with any adjustment for twisting or side bending (lateral flexion) of the trunk/back. Trunk flexion is defined as anterior (forward) movement of the trunk in the sagittal plane (think toe touching). Trunk extension is defined as posterior (backward) movement of the trunk in the sagittal plane (think painting the ceiling).
In this example, the trunk position was observed to be flexed more than neutral up to 20 degrees (+2). There is no significant trunk twisting or side bending, so the trunk adjustments do not apply and neither box is checked.
Step 11: Legs
The leg position score will be 1 or 2. If legs and feet are supported with even weight distribution the score is +1. If the legs and feet are not supported or there is uneven weight distribution, the score is +2.
In this example, the legs and feet are supported and weight is evenly distributed, therefore the leg score is +1.
Step 12: Table B posture score. Look up the neck (3), trunk (2) and leg (1) scores in Table B on the worksheet. In this example, the Table B posture score is 3.
Neck, trunk and leg muscle use and force/load
Step 13: Muscle use. Add +1 if the posture of the neck, trunk and legs is mainly static (held for longer than 1 minute) or the action is repeated 4 times per minute or more. If neither applies, the muscle use score is 0.
Step 14: Force/load. Choose one of the same four options for the neck, trunk and legs:
- Less than 4.4 lb (2 kg), intermittent: +0
- 4.4 to 22 lb (2 to 10 kg), intermittent: +1
- 4.4 to 22 lb (2 to 10 kg), static or repeated: +2
- More than 22 lb (10 kg), or repeated loads or shocks: +3
In this example, the muscle use score is 0 and the load is 4.4 to 22 lb, static or repeated (+2).
Step 15: Neck, trunk and leg score. Add the Table B posture score, the muscle use score and the force/load score: 3 + 0 + 2 = 5. This is the column to use in Table C.
Calculate results
Find the Table C score where the wrist and arm score row (7) meets the neck, trunk and leg score column (5). In this example, Table C gives a final RULA score of 7.
| Step | Score |
|---|---|
| Table A posture score (upper arm 4, lower arm 2, wrist 4, wrist twist 1) | 5 |
| Wrist and arm score (Table A plus muscle use 0 and force/load 2) | 7 |
| Table B posture score (neck 3, trunk 2, legs 1) | 3 |
| Neck, trunk and leg score (Table B plus muscle use 0 and force/load 2) | 5 |
| RULA score (Table C) | 7 (investigate and implement change) |
| Risk index (7 ÷ 3) | 2.33 |
The RULA score represents the level of MSD risk for the job task being evaluated. The minimum RULA score is 1 and the maximum is 7. The design goal for the RULA assessment is a score of 3. The risk index answers the question… “How significant is the risk?” A risk index of 1.0 or less indicates a nominal risk to healthy employees. A risk index greater than 1.0 denotes that the task is high risk for some fraction of the population. As the risk index increases, the level of MSD risk increases correspondingly. Therefore, the goal is to design job tasks to accomplish a risk index of 1.0 or lower.
In this example, the final RULA score of 7 and a risk index of 2.33 indicate high risk and call for further investigation and engineering and/or work method changes to reduce or eliminate MSD risk. See this example in the free RULA calculator.
Improving the job: from a RULA score of 7 to 1
To reduce the level of MSD risk, the assembly process was changed to install the access plate prior to riveting the can together. A fixture was fabricated to hold the can open while the access plate is being installed. A straight or “in-line” pneumatic screwdriver (on a tool balancer) is now used to improve upper extremity work postures and eliminate the force required.
A follow-up analysis using the ErgoPlus Industrial software RULA calculator was performed upon completion of this ergonomic process and tool improvement. The results are pictured above. When using the new work process and tools, the RULA total score is reduced from 7 to 1 and the risk index is reduced from 2.33 to 0.33.
RULA vs REBA
RULA and REBA were both co-developed by Lynn McAtamney and use the same worksheet approach. The difference is how much of the body they score, so pick the one that matches where the work happens.
| RULA | REBA | |
|---|---|---|
| Full name | Rapid Upper Limb Assessment | Rapid Entire Body Assessment |
| Published | McAtamney and Corlett, 1993 | Hignett and McAtamney, 2000 |
| Body parts scored | Upper arms, lower arms, wrists, neck and trunk, with a simple leg score | Neck, trunk, legs, upper arms, lower arms and wrists |
| Also scores | Muscle use and load | Load, coupling (grip) and activity |
| Final score | 1 to 7, four action levels | 1 to 15, five risk levels |
| Best for | Work done mainly with the arms and hands, such as assembly or computer work | Whole-body tasks, handling loads, and unstable or rapidly changing postures |
To score a whole-body task with REBA, see our step-by-step guide to REBA or try the free REBA calculator.
FAQ
Common questions about RULA
What does RULA stand for?
RULA stands for Rapid Upper Limb Assessment. It is an observational ergonomic assessment tool that scores the risk of upper-limb musculoskeletal disorders from a worker’s posture, muscle use and force, and gives a single score from 1 (acceptable posture) to 7 (investigate and implement change).
Who developed RULA?
RULA was developed by Lynn McAtamney and Nigel Corlett and published in Applied Ergonomics in 1993. McAtamney later co-developed REBA with Sue Hignett, which extends the same approach to the whole body.
What are Tables A, B and C in RULA?
Table A combines the upper arm, lower arm, wrist and wrist twist scores into one posture score for the arm and wrist. Table B combines the neck, trunk and leg scores into another. After adding muscle use and force/load to each, Table C crosses the wrist and arm score (the row) with the neck, trunk and leg score (the column) to give the final RULA score.
What is the RULA risk index?
The risk index is the RULA score divided by 3. ErgoPlus uses it so a RULA result can be read on the same scale as the NIOSH lifting index: a risk index of 1.0 or lower (a RULA score of 3 or lower) is the design goal, and anything above 1.0 means the task is high risk for some workers.
How do the muscle use and force/load scores work in RULA?
Each half of the worksheet gets its own muscle use and force/load score. Muscle use adds +1 when the posture is mainly static (held for longer than a minute) or the action repeats 4 times a minute or more. Force/load adds 0 to 3: 0 for less than 4.4 lb used intermittently, +1 for 4.4 to 22 lb intermittently, +2 for 4.4 to 22 lb static or repeated, and +3 for more than 22 lb, or repeated loads or shocks.
Is RULA only for seated work?
No. RULA works for seated and standing tasks: the legs score +1 when the legs and feet are supported with weight evenly balanced, and +2 when they are not. It fits best when the arms, wrists and neck do most of the work. For tasks that load the whole body, such as lifting or awkward reaches with the legs, REBA is often a better fit.
When should I use the NIOSH Lifting Equation or the Snook Tables instead of RULA?
RULA scores posture, muscle use and force for the upper body. When the main risk is the weight being lifted or lowered, the NIOSH Lifting Equation gives a recommended weight limit and a lifting index. For pushing, pulling and carrying, use the Snook Tables.
Is there a RULA worksheet PDF?
Yes. Download the RULA Employee Assessment Worksheet (PDF) to score a task by hand, or use the free RULA calculator, which follows the same 15 steps and prints a one-page summary.
References
- McAtamney, L., & Corlett, E. N. (1993). RULA: a survey method for the investigation of work-related upper limb disorders. Applied Ergonomics, 24(2), 91–99. https://doi.org/10.1016/0003-6870(93)90080-S
- Hignett, S., & McAtamney, L. (2000). Rapid Entire Body Assessment (REBA). Applied Ergonomics, 31(2), 201–205. https://doi.org/10.1016/S0003-6870(99)00039-3
- RULA Employee Assessment Worksheet, based on McAtamney and Corlett (1993).
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