The Push and Pull of Workplace Ergonomics
Editor’s note: This post is the first in a series based on selected educational sessions held at AIHce EXP 2018.
At a session entitled “The Snook and Ciriello Tables for Manual Material Handling Analysis” at AIHce EXP 2018 in Philadelphia, Certified Professional Ergonomist Blake McGowan explored the expensive reality of ergonomic overexertion injuries.
“I hear from a lot of safety professionals and industrial hygienists. We are the ones who are responsible for ergonomics. But we're not really that confident that we know what ergonomics is,” said McGowan, who is the managing consultant and research specialist for Humantech, Inc., in Ann Arbor, Mich. He oversees large-scale ergonomics initiatives and helps organizations to build internal ergonomics expertise.
“I wish as safety professionals, as IHs, that one day we will treat our people as good as we treat our machines. If we did, we'd have far fewer problems in the world of ergonomics,” McGowan said. “We never ask a machine to do what it's not capable of doing. We always ask people to do things they're not capable of doing. It still shocks me that most Fortune 1000 companies don't have a single, dedicated person responsible for ergonomics.”
According to McGowan, ergonomics overexertion injuries, which are caused by excessive physical effort, are the biggest threat facing workers and their employers. “Overexertion injuries—related to lifting, lowering, pushing, pulling, carrying, throwing types of activities—account for about 25 percent of all nonfatal occupational injuries in the U.S.,” he said. “That accounts for roughly $14 billion per year. That’s roughly $30 million a day. That's how much money we invest in first hurting and then healing people with regards to these types of injuries.”
It’s a problem that requires corporate focus. “Three of the top thirty global burdens of disease are soft tissue injuries that are related to occupations, yet we don't use this data to help drive change within our organizations,” McGowan said. “We get a nickel budget to solve a billion-dollar problem. We need to start to educate people on how big of a problem this is.”
Proper Measurement to Prevent Injury
McGowan pointed to the simple Snook and Ciriello Tables for Manual Material Handling Analysis, developed in 1991, as an excellent tool to determine maximum acceptable weights for various work tasks from just a handful of inputs. The capability tables are the work of Stover Snook and Vincent Ciriello of the recently closed Liberty Mutual Research Institute for Safety. For McGowan, the weight limits are an essential inclusion in an ergonomics professional’s toolbox. “The researchers who have developed these tools did a really nice job of simplifying how we can quantify the acceptability of things like lifting, lowering, pushing, pulling and carrying,” he said. “The Snook and Ciriello tables are really, really simple and they are still valid. Keep using them.”
McGowan shared five tips for taking good force measurements in the work environment:
1. Invest in attachments. “Any time you buy a force gauge, plan for and budget for all the attachments possible,” McGowan said, “and then make a couple of good friends in your machining area and they'll design a few others for you.”
2. Make it realistic. Ergonomics professionals need to account for the fact that not all workers perform tasks the same way. “There’s all types of ways that people push and pull,” McGowan said. “Just make sure you’re doing it as realistically as possible.”
3. Consider the casters. Maintenance of equipment intended to help move materials is sometimes overlooked. “Are the casters damaged, too small, or are the bearings worn out? That’s what we find in industry where we have hundreds of carts within a workplace,” McGowan said. “It's very easy for one or two of them to become damaged and never to be maintained.”
4. Try it ten times. “Typical good practice is to push or pull something ten times over different surfaces,” McGowan said. “Casters have different characteristics depending on where they are on the floor. The floor has different characteristics: You might be going slightly uphill, slightly downhill, heat might impact it. Try it in multiple different environments just to get a broad range. We typically take the mean to extract the outliers.”
5. Consider the force. The force applied during a push or pull is most important—make sure to measure it accurately, McGowan said.