Ergonomic News: A Different Perspective on Ergonomics Assessment Tools

The goal of a well-designed assessment tool is to take the information that has been gained through research on the causes and impact of strain on the human system, and organize questions, calculations or data to help visualize and predict when this strain is reaching levels that could lead to work-related musculoskeletal disorders.

Over the past 30 or so years, a significant number of ergonomics assessment tools have been published in journals in an effort to advance the methods that we use to perform ergonomics evaluations. A short list of these tools would include: QEC, manTRA, RULA, REBA, HAL-TLV, OWAS, LUBA, OCRA, SNOOK tables and the NIOSH lifting equation. After trying out many of these tools personally and considering their usability, reliability and validity, a question came to mind on how the health and safety community perceives the usefulness of these ergonomics assessment tools.

To gain some insight into this question, I handed out a questionnaire to my audience while giving a talk on ergonomics assessment tools at the National Ergonomics Conference and Exposition (NECE) in Las Vegas. The survey included questions on whether the person was aware of various tools that have been published over the years, whether they used the tool and whether the tool has been established as a component of their companies ergonomics program.

Six tools bubbled to the top of the list as the most commonly used assessment processes. The NIOSH lifting equation was the most prominent tool, with 77 percent of the attendees recognizing it and 69 percent have experience using it. The SNOOK tables were close in recognition (62 percent), but used far less often (38 percent). RULA, REBA, the Strain Index and the Washington State checklists all were recognized by about half the group, and were used by an average of 40 percent of the audience. The remaining tools sporadically were recognized and seldom used. Interestingly, only NIOSH and SNOOK achieved any real level of use within the audience’s ergonomics programs (~40 percent).

As a consultant and ergonomist I had a double interest in learning where people were finding the tools that they used. Almost every consulting group has developed their own ergonomics assessment tools, and I was curious if the audience relied heavily on the expertise of these groups or went searching for their own assessment options.

The most common location where people looked for assessment tools was the internet (77 percent), followed closely by creating their own tools (69 percent) and then by finding the tools in research articles (58 percent). Only 35 percent of the attendees noted that they obtained the tools that they use from a consulting group. The concern with these results is that the majority of the audience relied on the internet or their own resources to obtain/develop their ergonomics assessment tools, and a much smaller percentage looked to ergonomics research.

To add to the concern and complicate the results, 80 percent of the responses indicated that validation of the tool is an important consideration. Finding resources on the internet, creating your own assessment tools and even looking to some of the tools developed by consultants, all are methods that may not lead towards truly validated approaches. Proper testing of tools is required to ensure the content and context validity of its design and output, and reliability is an equally critical component for any assessment process that is used within an ergonomics program.

Research should be the primary resource that an individual should tap if they are searching for a valid tool to help their ergonomics process. Care should be taken here as well to ensure that a tool that was presented in a single journal article was subsequently tested and validated in additional research projects. On the positive side, the six tools that bubbled to the top of the list for recognition and use are well documented and validated assessment tools.

The final question that I posed was related to what is the expected level of training required to become knowledgeable about ergonomics assessments. Some 65 percent of the respondents felt that a minimum of 4 hours was required, with >8 hours being the most common response. The goals with training on the use of ergonomics assessment tools were to learn how the tool was designed, how to collect the data relevant for the tool, how to apply the tool and how to interpret the results. The time required to learn this information can be relatively short (2 hours for basic tools), but the consistent application and interpretation of the data takes practice. This is where the additional time is required. Reliability is an important piece of the puzzle with ergonomics assessments, as it would be impossible to use a team to collect data or trust before/after assessments if the application of the tool is inconsistent.

Based on the results obtained from this quick survey of a small sample of users, it appears that the health and safety community is looking for basic, objective, user-friendly, validated assessment tools to enhance their ergonomics process. People appear to be ready to spend the time to learn how to apply these tools, and hopefully sufficient time is taken to develop good, consistent processes. For those who want to learn more about the ergonomics assessment tools that are available and learn how to apply these tools effectively, the following resources should be of assistance:

NIOSH – Free resources, including detailed instructions on application of lifting equation: http://www.cdc.gov/niosh/topics/ergonomics

Washington State Department of Labor and Industries – Free resources, including hazard checklists and case studies: http://www.lni.wa.gov/Safety/Topics/Ergonomics/default.asp

Liberty Mutual – Free resources including updated tables for the assessment of material handling activities: http://libertymmhtables.libertymutual.com/CM_LMTablesWeb

MSD Prevention Toolbox – Free guidelines and information developed by the province of Ontario, Canada: http://www.wsib.on.ca/wsib/wsibsite.nsf/public/PreventMSD

Analysis Tools for Ergonomists – Free website with data collection forms and MS Excel programs to help perform assessments: http://personal.health.usf.edu/tbernard/ergotools/index.html

Fundamentals and Assessment Tools for Occupational Ergonomics – Purchase text online (edited by Dr. Marras and Dr. Karwowski); provides insight into basic assessment process and individual assessment tools. References are provided.