If you use Humantech’s industrial ergonomics software, this short explanation of risk scoring is worth the read. After sitting in on a client discussion about the difference between whole-body scoring and individual-body-segment scoring, I asked certified ergonomist and member of our research team Rick Barker for clarification. Here’s what he said:
The correct question isn’t which score to use, but rather, how to best use each since both provide valuable, but different information.
The whole-body score, or Risk Priority Score, provides the big-picture view of ergonomics in your organization. This score helps you prioritize facilities, departments, and jobs for improvement. It also provides a way to track overall risk reduction. However, it is not the best indicator of the likelihood of a musculoskeletal disorder, or MSD, for a specific job.
MSDs are the result of risk exposures in specific body segments, rather than overall body exposure. Therefore, the best way to understand the risks of developing an MSD while performing a specific job is to examine the individual body segment scores. For jobs with a high Risk Priority Score, the emphasis of improvements should be on the body segments with a high risk score. Reducing the Risk Priority Score by removing risk exposure from high-risk body segments will reduce the likelihood of injury more than doing the same for other (moderate- or low-risk) body segments. Every reduction in the Risk Priority Score is good, but some reductions are better than others; focusing on the most effective ones will help you reach your injury reduction goals sooner.
In most cases, a job with a body segment that has a high risk of MSD will also have a high overall score for the whole body. However, in jobs where the exposures are concentrated in one area of the body, the whole-body score can be moderate even though the score for one body segment is high. These jobs are also important to improve. The individual body segment scores are the best prediction of MSD likelihood in a job, so address high-risk body segments regardless of the Risk Priority Score.
In summary, to get the best results in your ergonomics process:
- use the Risk Priority Score to manage and track your overall efforts, and
- focus on the individual body segment scores to drive risk reduction.