Ergonomics Risk Assessment: Determining When, Why, Who and How You Should Perform One

April 15, 2008
In Part I of this two-part series, the author examines why and when ergonomics risk assessments should be performed.

As ergonomics increasingly becomes a core component of safety programs around the country, the methods used to evaluate and define the ergonomics risk present in a job develop into a critical element of the ergonomics process. When a company begins to look at ergonomics and how to implement an effective process, the basic job analysis is often the starting point, and the point that defines how a company will approach the analysis and abatement of ergonomics risk.

Identification of ergonomics stressors that are linked with the development of musculoskeletal disorders is a key element of any ergonomics activity. In most cases, stressors successfully can be identified using observational and checklist-driven techniques. The detection of ergonomics risk does not require advanced tools or techniques.

This observational approach often the most efficient method of gathering data on the stressors in the working environment, but the density of this data is limited. There is no measure of exposure, risk or any data that will provide a quantitative measure that can be tracked (i.e. improvement of process). The positive characteristics of this type of stressor identification process are the ease in which it is performed, the low cost of the assessment and quick turnaround times. A simple observation approach often can be used to feed a quick fix of an obvious ergonomics stressor. As the situation becomes more complicated, intricate or costly, the need for a more sophisticated approach may present itself.

When a company is interested in advancing its ergonomics job analysis process, the next level of assessment involves the use of risk assessment tools. Now, the term “tool” is used lightly, in that ergonomics risk assessment methods largely are paper-based, with some methods computerized for ease of use. There seldom are complicated pieces of equipment involved, except for a force gauge in some situations. Prior to using an ergonomics risk assessment tool, a company should ask four simple questions:

  • Why should we use an ergonomics risk assessment tool?
  • Who will be performing the assessments?
  • How do we use the risk assessment tool correctly?
  • When should we use a specific ergonomics risk assessment tool?

This paper will walk through these four questions to provide a guide to adding ergonomics risk assessments to a safety or ergonomics program.

Why and When Should You Perform an Ergonomics Risk Assessment?

Where ergonomics is concerned, there are often three questions asked:

  • Which jobs pose the greatest risk?
  • How much is too much?
  • How can I show improvements were made?

One of the first steps in ergonomics evaluations is to identify the stressors present in the jobs. This identification usually is accomplished with a subjective evaluation. The evaluator may identify such things as high repetition, high force and/or extreme posture as being present in a job without any measurements. While this type of evaluation may be effective for determining which jobs may need further investigation, the severity of the identified stressors often is difficult to express and/or document. Furthermore, it is difficult to compare different jobs or tasks within a job to determine a prioritization of ergonomics efforts. This leads to the question: “Which jobs pose the greatest risk?”

Ergonomic interventions may not completely eliminate the stressors. They may be reduced but still be present. Additionally, as long as humans are involved in the workplace, there will be ergonomic stressors placed on those individuals. Therein lays the question: “How much is too much?”

Some interventions may address a stressor identified in the original evaluation and create another stressor. Therefore, once interventions are in place they should be evaluated to ensure they eliminated or reduced the stressors identified in the original evaluation without creating another hazard. This begs the question: “How can improvements be shown and evaluated?”

Some answers to these questions may be found through the use of ergonomics risk assessment tools. The use of quantitative or semi-quantitative evaluation tools provides the evaluator with numeric output with which they may evaluate the risk for the development of MSDs for a given job. This output also may allow them to compare relative risk of multiple jobs or tasks, thereby identifying the jobs or tasks that pose the greatest risk. This may assist the evaluator in the prioritization of ergonomics efforts.

These tools also may provide the evaluator or designer with recommended limits to the stressors present in a job, task or job design. These limits may be used to assist in reducing the risk to safe levels. Furthermore, the results may be used to compare the same job or task before and after an intervention is put in place.

Part II of this series, “Ergonomics Risk Assessment: Determining When, Why, Who, and How You Should Perform One,” will appear in the May newsletter.

Contributing Editor David Brodie, MS, CPE, ([email protected]) is director of ergonomics services for Atlas Ergonomics. Atlas Ergonomics, LLC is a leading ergonomic service and technology provider, helping customers reduce the spiraling costs of work related injuries within industrial, office, and commercial driver environments. Atlas Ergonomics provides turnkey support through a nationwide network of providers or can assist corporate resources with the necessary training and technology. Atlas Ergonomics is located in Grand Haven, Mich., and additional information can be found at

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