Safety Catalyst: The Power of Incorrect Ergonomic Thinking

May 1, 2006
The science and art of ergonomics helps safety strategists make adjustments that bridge the gap between people and their work.

The aim of ergonomic design and/or behavior modifications is to create safer and more efficient performance, as well as boost worker satisfaction. A one-size-fits-all approach, while understandably easier to implement, is antithetical to effective ergonomic interventions, and only will help to a point of diminishing returns, in the same way that a second scissors lift brought in to sit right next to an existing one is unlikely to further reduce injuries.

Too often, we've heard of ergonomic interventions that solely are based on preprinted checklists that treated all workers as if they were identical. This doesn't make sense to me as a developer of soft-tissue injury and other prevention interventions.

Sometimes pressures to be "politically correct" would have us pretend that everyone is exactly the same, with equal risks and identical concerns. As one of my colleagues, Paul McClellan, responds when asked about the "best" way to do a job, "Best for whom? A 5-foot-6-inch, 52-year-old worker who's had previous back injuries or a newly hired, 6-foot-7-inch, 25-year-old worker with no history of being injured?"

No surprise that in addition to age, height and experience, gender differences also can affect safety. Of course, "different" doesn't mean "superior" or "inferior."

Contributing Factors

While we never should be offensive nor invasive, it is critical for strategic leaders to see and address those actual contributors to safety problems. These include biological design and past environmental influences.

Start by recognizing that men and women may be vulnerable to potential injury in different ways. Some males may have an I'm-too-tough-to-get-hurt attitude or at least won't admit it when they do get hurt that can lead to a higher level of risk-taking. Physically, I've seen many men default toward applying upper-body strength in heavier work; this can increase the risk of lower-back injuries.

And statistically, men consult with physicians at a significantly lower rate than do women. It may be that, relative to women, men in general either don't recognize internal signals of disorder/injury or just direct less attention toward what is happening in their bodies. So whether this is an issue of not seeing or not admitting that potential damage is building, it becomes more difficult to head off problems at the pass. And because forces transfer through the body, untreated foot pain can lead to knee problems, lower back pain to neck pain and more.

On the other side, women have other potential safety problems. For example, many females have proportionately less upper-body strength than men. Yet, I've seen training, job safety analyses (JSA) and policies/procedures that, perhaps unknowingly, seem to direct all workers to first apply upper-body strength to accomplish tasks. This kind of male-oriented safety intervention may exacerbate potential injuries.

Women are especially vulnerable in the knees. Renowned New York Times health writer Jane Brody wrote that 12 million women each year visit doctors for knee-related problems, and that females may be up to eight times more likely to sustain serious knee injuries than men.

Why? Females have wider hips than do men, affecting the angle of the femur into the knee joint. Women have looser knee joints as well. These biological design differences make women's knees more prone to turning inward. Whether due to use or biology, women tend to rely more on their quadriceps to stabilize the knee than on the stronger hamstrings, according to research at the University of Michigan. This can result in greater vulnerability to ligament injuries.

Here are some ways to improve ergonomics:

  • Suggest that anyone with potential knee problems female workers, older populations, those with previous knee injuries reduce their jumping and learn the best foot, knee and hip alignment to land as softly as possible.
  • On an organizational level, invite women on safety committees to become more actively involved in testing proposed tool or equipment changes. Ask these members to specifically look for and evaluate training, tooling or JSA methods to be sure they are suitable for female workers across a range of heights, condition and age, as well as for all other employees.
  • Create an atmosphere where professionals, managers and bargaining unit and safety committee members are seeking out methods and equipment that promote effectiveness. Be sure to work with your human resources department (and in some cases, legal department) toward these ends.

High-level ergonomic thinking relies on seeing the specific issues of your work force and making needed adaptations. Steadfastly embrace the goal of attaining next-level safety performance, even when it means being willing to be considerately "incorrect."

Robert Pater ([email protected], is managing director of Portland, Ore.-based Strategic Safety Associates.

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