Column Personnel Safety

Trades People Need Ergonomics, Too

Klaus M. Blache | May 17, 2018

Harnesses and other personal-protection equipment provide needed safety but can also introduce ergonomic factors that must be addressed, particularly for trades personnel.

Q : How does ergonomics apply to trades?

A: Ergonomics (human factors) is made up of two Greek words, ergon (to work) and nomos (law). OSHA (Occupational Safety and Health Administration, Washington, defines ergonomics as the study of work.

More specifically, ergonomics is the science of designing the job to fit the worker, rather than physically forcing the worker’s body to fit the job. From all of that comes the oft-used phrase “work smarter, not harder.”

Much of the manufacturing-oriented ergonomics research and resulting information has been applied to production operators. That’s because associated problems are observable, identifiable, and predictable due to the repetitive nature of their work.

Ergonomics, though, is just as important for trades personnel because of situations they constantly encounter. Examples include:

• The static loads that result from holding something in place for a long time during installation is a significant stressor.

• The emergency nature of trades work may not promulgate the best ergonomic practices, even though all safety practices are followed.

• The unpredictable nature of repair and replacement frequently forces awkward postures and hand-wrist positions.

• Tools and harnesses, in combination with often-tight workspaces, lead to awkward body postures and movement, such as more twisting, sustained holding, and unbalanced lifting positions.

• Safety helmets and glasses, hearing protection, arc-flash suits and gloves, and other personal-protection equipment, although necessary, interfere with performing needed tasks. Factors include grip strength, perception, reaction time, motion limitation, and visibility.

• Poor accessibility, lack of proper visual displays/error proofing needs are different for skilled trades who need to maintain machinery and equipment that is typically not designed and/or installed for maintainability.

• The impact of ergonomics also increases with multiple shifts and long work hours.

Age is a factor

As another popular phrase states, “with age comes wisdom.” Unfortunately, that’s where the good news stops. Everything else declines with age. As years pass, we humans deal with a loss of muscle fibers and strength, range of motion, aerobic capacity, eyesight, grip strength, cardiac output, nervous-system capability, and mental processing.

Most of these functions decline at a steady rate until about age 50, at which point the rate of deterioration usually increases. Workers aged 50 to 60 need two to three times more light (to maintain visual acuity) than a younger worker. Since people are living longer and many working longer, understanding these changes becomes even more important.

In a study that I performed on skilled trades regarding lower-back problems, the number of lower-back medical visits increased with age. In a NIOSH Mining Industry study (National Institute for Occupant Safety and Health, Washington,, most older injured workers had the highest number of days lost per injury. NIOSH recommends further accommodations for aging workers regarding physical demands (including static muscular work), lifting and carrying, repetitive movements, and awkward postures.

With all of these aging-related physical and cognitive changes, being proactive with additional ergonomic considerations is key to preventing injuries and long-term business success. In 2014, OSHA estimated that work-related musculoskeletal disorders in the United States accounted for more than 600,000 injuries and illnesses. This was 34% of all lost workdays reported to the Bureau of Labor Statistics, Washington ( These disorders account for one out of every three dollars spent on worker compensation. In 2016, OSHA reported that sprains, strains, and tears accounted for 30% days-away-from-work cases in manufacturing.

Musculoskeletal factors

Musculoskeletal disorders (MSDs ) involve the muscles, nerves, and tendons, and are also referred to as CTDs (cumulative-trauma disorders).

Work-related MSDs, including those of the neck, upper extremities, and lower back, are one of the leading causes of lost workdays. Workers in many different industries and occupations can be exposed to risk factors such as lifting heavy items, bending, reaching overhead, pushing and pulling heavy loads, working in awkward body postures, and repetitively performing tasks. Exposure to these known MSD factors increases a worker’s risk of injury.

Many manufacturing facilities have been applying ergonomics concepts on the plant floor, for safety and to help sustain a level of productivity. My studies show a linear relationship between good ergonomics and reduced absenteeism. In turn, higher absenteeism was related to greater quality defects (this relationship was curvilinear, meaning that quality defects increased at a faster rate, with increasing absenteeism). Safety and ergonomics go hand in hand and, addressed properly and consistently, will result in a workforce that shows up and produces quality product.

More than 35 years ago, I was on a team that put together the initial ergonomics process for General Motors. Today, there are many more technological and interactive capabilities available. Just a few examples are ergonomic gloves to increase grip strength, scanners on gloves to minimize repetitive movement, unique mechanical assists, and ergonomic clothing. Also, when in Germany in 2017, I noticed that one grocery store had attached magnifying glasses to all of their food carts to accommodate aging customers.

Operations of the future will win at the plant-floor level. Ergonomics can support various initiatives, such as design for manufacturing, minimizing physical stress, improving decision making to reduce defects, and improved machinery and equipment maintainability. EP


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Klaus M. Blache

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