Tools for Ergonomic Assessment of Manual Handling Tasks
- Available Online Calculators, Printable Tables and Models for Lifting, Lowering, Pushing, Pulling or Carrying Loads at Work

Need to carry out an ergonomic assessment for the manual handling of loads, and want to know the answers to the following questions?

How much can I lift, push, pull or carry in a given situation?
How high a risk is associated with the weight of the load I need to have lifted?

Then hopefully this risk assessment page will lead you to the answer fairly quickly. You see, there are a decent number of both electronic and analogue tools out there to help you risk assess a certain manual handling task.

But before you dive into these ergonomic tools, you need to be absolutely clear about a few things such as the type of:

• TASK - What kind of manual handling operation do you want to evaluate? Some ergonomic tools are only for lifting others also include the motions of pushing, pulling and carrying.
• OUTPUT - What question you do need to answer? Some tools provide a maximum recommended weight limit / maximum recommended force to be applied to a certain manual handling job. Other ergonomic assessment tools others give you e.g. a risk value, thus telling you if this job is considered dangerous to perform.
• COMPLEXITY - Does the tool need to be easy and quick to use? Some tools are fairly technical and extensive (such tools are mostly targeted health and safety personnel) and may take a while understand and use. Other tools are simple and easy to use, making them ideal for the busy employer or worker that only has a few minutes to spare and want a quick indication of risk.
• FORM - What kind of tool type do you want? Some risk assessment tools come in the form of free online calculators, other ergonomic assessment resources exist as printable tables and sheets, and yet others are paid for hardware and software.

We hope that with this guide, you can find the ergonomic assessment tool for manual handling best suited your needs.

First, let's begin with what is probably the most famous tool of all, The NIOSH Lifting Equation.

The NIOSH Lifting Equation

Task: Lifting
Output: What is the recommended weight limit for a certain lifting task
Complexity: Technical and complex
Form: Online calculator and equation

This first manual lifting calculator, the NIOSH Lifting Equation, is an absolute 'must know'. The NIOSH Lifting Equation was the first of its kind (originally from 1981, revised in 1991), and is the 'mother' (the technical basis) of most other manual lifting calculators.

With the NIOSH Lifting Equation, you can find out how heavy a load you can lift during a very specific lifting operation. In other words, the equation will give you the Recommended Weight Limit (RWL) for a certain lifting task.

Furthermore, once you have the RWL, you can make yet another calculation that will give you a number on the Lifting Index (LI), which will inform you if the load that you are to lift puts you at too high a high risk of injuries, impairment, MSD, low back pain etc.

The NIOSH Lifting Equation is not all that simple to use, however. You need to know a lot of data - 6 unique variables to the lifting task. The 7th, though, (the Load Constant, LC) is a constant of 51 pounds / app. 23 kilo.

The NIOSH Lifting Equation looks like this:

RWL = LC x HM x VM x DM x AM x FM x CM

Yes, a lot of things to multiply; For instance you need to know how many degrees your trunk turns when lifting (AM) or how far you are lifting the load in cm / inches (DM) etc. to be able to use the equation correctly.

But if you're keen on giving it a go, you can go to these online NIOSH Lifting Equation calculators and try plotting in the variables:

The NIOSH Lifting Equation calculator from The Canadian Centre for Occupational Health and Safety

The NIOSH Lifting Equation calculator from Ergo-Plus 

If you want to know more detailed information on the NIOSH Lifting Equation, we have created an in-depth page for you to explore here.

The Oregon OSHA Lifting Calculator App

Task: Lifting
Output: What is the recommended weight limit for a certain lifting task
Complexity: Simple and easy to use
Form: Online calculator

Oregon's Occupational Safety and Health Administration (Oregon OSHA) and the Washington State Department of Labor & Industries have joined forces and have developed a simplified version of the NIOSH Lifting Equation calculator for those who want a quick estimate of the maximum weight of a load pertaining to a certain lifting task.

To find the recommended weight limit (RWL) you only need to insert three variables, and then at the end judge your result in the light of how much you estimate that you twist your trunk.

So you need to have an approximate idea of:

1. The height where the lift begins
2. The number of lifts per minute
3. The overall hours of lifting per day

When you have fed the calculator this data, you get two weight results to choose from: one for trunk-twisting over 45 degrees and one for trunk-twisting less than 45 degrees. Chose which one applies to you, and you will have the recommended weight limit for your task.

The Oregon OSHA Lifting Calculator app is available on may platforms - both as an online ergonomic assessment tool and a downloadable app from the App Store or Google Play.

The Ohio Bureau of Workers' Compensation (BWC) and Ohio State University's (OSU) Lifting Tools

Task: Lifting
Output: How heavy a load can you lift if you are 'healthy' vs. have low back pain
Complexity: Simple and easy to use
Form: Risk assessment sheets and calculator

Not only is back injury is serious problem for a surprisingly high number of workers nowadays, but second back injury (when people return to work and carry on with their previous lifting tasks) is unfortunately also very frequent and just as problematic.

I order to prevent both initial and subsequent MSDs, The Ohio Bureau of Workers' Compensation (BWC) and Ohio State University's (OSU) have merged their efforts in an ergonomic research project with the aim of reducing the frequency and severity of back injuries happening in the workplace.

The result of this research project is based on a lab study of 23 test individuals.

As a result the following ergonomic assessment tools for lifting were developed:

1) Lifting guidelines charts with trunk-twisting degrees as the main differentiating factor of the three charts. The second differentiating factor is whether you are 'healthy' (i.e. haven't had a back injury) or whether you suffer from LBD (lower back disorder). These conditions (and other conditions shown in the charts) will affect the recommended weight limit.

2) A manual lifting calculator.
Compared to the NIOSH Lifting Equation and the non-simplified online calculators for it, this tool is very easy to use. The data that you have to feed it is presented as examples where you just have to choose which one comes closest to your reality. Easy, but of course also less precise. Again, the main variable is whether or not you have low back pain.

Modified WISHA (Washington Industrial Safety and Health Act) Risk Assessment for MSDs and Lifting Operations

Task: Lifting
Output: Does your lifting task constitute a risk
Complexity: Fairly simple and easy to use
Form: Risk assessment sheets and online calculators

Washington State Department of Labor and Industries has, among other things, created two risk assessment checklists. A Hazard Zone Checklist and a Caution Zone Checklist. These ergonomic assessment checklists are intended to identify physical risks associated with certain movements and postures at work.

Thomas E. Bernard (Ph.D. in Occupational Health) has then combined these two ergonomic assessment checklists into a third risk assessment sheet specific for MSD, thus with a high focus on lifting operations.

Another risk-based ergonomic assessment sheet he has created focuses on lifting tasks specifically. You can find it here.

This document consists of two parts. The first one is a hazard screening to see if there is any danger inherent in your lifting job. If you 'fail' that (meaning there is risk associated with the lifting task), you will move on to the second part of the ergonomic assessment document, where you will analyse your lifting operation in more detail.

If you want to try some WISHA online calculators, you may have a go at these:

WISHA Lifting Calculator from EasyCalculation.com
WISHA Lifting Calculator from ErgoPlus

WorkSafeBC's Pushing, Pulling and Carrying Calculator

Task: Lifting, carrying, pushing, pulling
Output: How heavy a load may you lift or carry and how much force may you use for pushing or pulling
Complexity: Simple and easy to use
Form: Online calculator

The Workers' Compensation Board of British Columbia (WorkSafeBC) is a statutory agency that functions as the exclusive workers' compensation insurer in British Columbia, Canada.

WorkSafeBC have created a some simple online calculators for:

1. Generating the maximum force applied when either pushing or pulling.
2. Calculating the maximum recommended weight when lifting or carrying.

The data behind this calculator comes from the manual handling study called the Snook tables and the NIOSH Lifting Equation.

Have a go at WorkSafeBC's ergonomic assessment tool:

The WorkSafeBC's calculator

Snook Tables Calculator

Task: Lifting, lowering, pulling, pushing and carrying
Output: How high a percentage of males and females can carry out a certain manual handling task
Complexity: Complex tables, but simple calculators
Form: Tables and online calculators

The Snook Tables were developed by Dr. Stover Snook and Dr. Vincent Ciriello V. M. at the Liberty
Mutual Insurance Company and are to find in publication The
design of manual handling tasks: revised tables of maximum acceptable weights and
forces", Ergonomics, 34, 9 ,1991.

Using the Snook Tables you will find weight and force values that are deemed acceptable to a certain types of manual handling tasks (lifting, lowering, pulling, pushing and carrying) applicable to a certain percentage of the population.

In other words, if you have a certain manual handling task, then when using these ergonomic assessment tables, you will be able to see how high a percentage of males or females are capable of carrying out the task.

If you have a mixed workforce of males and females carrying out the manual handling task, you want the task to be acceptable to at least 75 percent of the female population and acceptable to at least 90 percent of the male population. If it is not acceptable to at least 75 percent of the overall population it is considered problematic. (reference)

So while the NIOSH Lifting Equation provides you with a very precise weight limit recommendation for a certain lifting task, Snook's tables is broader as it applies to more manual handling tasks, and can give you an idea as to whether or not your manual handling task is suited for men and / or women on a daily work basis.

If you like tables and lots of numbers, you can find the Snook Tables here.

If you want try some online calculators, you can follow these links:

Liberty Mutual Insurance's calculators. On their website you'll find manual handling calculators for every imaginable lifting, lowering, pushing, pulling and carrying task specifically intended for either men or women.
Ergo-Plus' calculator for pushing
Ergo-Plus' calculator for pulling
Ergo-Plus' calculator for lifting and lowering
Ergo-Plus' calculator for carrying
These calculators work a bit differently as you don't get a male / female population percentage but a "design goal" in terms of maximum load weight, which is then acceptable for a certain percentage of the population ("75% acceptable for women was selected as the appropriate target").
The Snook Lifting and Lowering calculator from EasyCalculations.com works in a similar way to the one above, providing a design goal acceptable to a certain percentage of the population (how much isn't mentioned, though).

Other Ergonomic Assessment Tools for Evaluating the Risks of Manual Handling

The Lumbar Motion Monitor
- The Sophisticated Hardware Tool for a Personalized Risk Assessment

At the Spine Research Institute at Ohio State University, The Biodynamics Lab has developed a tool, the Lumbar Motion Monitor (LMM) (it looks a bit like a bulletproof vest) that can measure the movements of a worker's lower back while performing a specific task.

These measurements are then compared to data in large databases which then provide an output in terms of estimated risk of injury for that specific job.

With the Lumbar Motion Monitor, they are able to, according to themselves, "objectively assess true dynamic activities in 3D, and are able to identify risk with three times more predictive power than standard government guidelines". 

3D Static Strength Prediction Program
- What Are the Physical Demands of a Certain Manual Handling Job?

At The Center for Ergonomics at the University of Michigan College of Engineering, resources has been put into developing a 3D Static Strength Prediction Program software that can analyze manual handling tasks and predict the static strength requirements for tasks such as lifts, presses, pushes, and pulls.

With the program you'll get a job simulation of the material handling task and the percentage of males and females estimated to be able to perform the job safely (a bit Snook Tables) along with data comparison to the NIOSH recommendations.

Other Related Pages

Manual Handling Regulations Guide

The NIOSH Lifting Equation

Ergonomic Risk Assessment Tools

Country Specific Pages with Ergonomic Guidelines and Risk Assessment Tools

UK	Germany	Austria	France	Ireland	The Netherlands
Denmark	Sweden	Spain	Portugal	Italy	Switzerland
Norway	Canada	Australia