There are some methods that are more rigorous and science-based than others, and naturally are more time-intensive. There are also stripped-down ways to get the job done faster and easier.
Ergonomists have various approaches depending on the situation. It may not be necessary to use analysis tools, to create elaborate written descriptions of before and after conditions or to measure and document the magnitudes of ergonomic stressors. These are all useful parts of a disciplined ergonomics process, but not necessarily do-or-die necessities for all ergonomics work.
One generally will see these aspects detailed in the work of outside ergonomics consultants who provide full documentation to their clients so the clients get as much beneficial information as possible. In such situations there is a need to provide the facts that back up recommendations for changes – before-and-after measurements so results can be weighed as successes or failures, data to show if a problem might need more work, comparative information for setting spending priorities, etc. This fully documented technical approach also is virtually mandatory for in-house ergonomics staff at larger companies.
Measurements usually are taken before and after ergonomic changes have been implemented. Measurements include various joint angles, estimates of hand gripping force and cycle times. These numbers can be plugged into analytical tools, the most well-known including Snook push-pull tables, the NIOSH “Lifting Equation,” the Job Strain Index and the Rapid Entire Body Assessment, comparing the measured states against established criteria. We also might see videos or still photos taken before and after as part of the documentation package.
A leaner approach to ergonomics might cut to the chase, hit the obvious issues first and mainly save that sort of technical deliberation and documentation for prioritizing where tightly budgeted resources will go.
The drawback to the lighter touch in analysis and documentation is a lack of hard data for all the various uses to which such data can be applied. But there is a substantial savings in the time necessary to accomplish something. The trick is to minimize the measurements and documentation without sacrificing any validity as a result.
Some of my clients practice this approach in their manufacturing cells. They use a system that lives on employee involvement. Rather than do a lot of intensive measurements and documentation, they look for the easy-to-spot, easy-to-fix issues. Since nothing they consider will cost much to change, there’s little need for elaborate deliberations or prioritization.
Employees had a short ergonomics class that included a brief, simple “hit list” of easily identified ergonomic issues. They were given the assignment to conduct a broad review their work areas against this hit list. The list contained standards that the company’s core ergonomics team (mostly hourly people) had decided the company should aspire to as closely as possible in all new lines and renovations. There was also a list of visible “ergo don’ts” to draw attention to some of the more obvious ergonomic stressors.
An example is in the company’s use of counterbalance suspension devices for powered hand tools. These counterbalances had been in use for some time when a new ergonomic initiative allowed the employees some time on the clock to review how effective they were. They decided some counterbalancers were taking the tools up much higher than necessary, some had more spring tension than necessary and some were detached from the tools and not used at all. Quick adjustments were made and the workstations were a little less stressful as a result.
In the case of the counterbalancers that were not in use, employees saw that the problem was in all cases a need for horizontal movement of the tool, yet the counterbalancers resisted more than a few degrees of motion. The counterbalancer cables were extended and the reels relocated to substantially higher mounting points. The horizontal movement was thus much greater within a few degrees of easy movement.
This employee team carried out their simple approach consistently over the course of a year and developed a long list of successes. It was easy to compare the before and after against the hit list, and there were other results to be seen later as time passed. Injuries dropped and the production rate improved.
These employees, having been the “parents” of their ergonomic ideas, were eager to see them succeed. They also had a personal interest in developing ways to cut costs (fewer injuries, better efficiency) that might stave off clumsy, morale-damaging staff reductions.
This example shows that a less-documented, leaner approach to ergonomics has its uses. It may not work for all or even most companies, but there are some out there who don’t want a thick report with numbers, pictures and appendices. All they want is some good ideas. A leaner, stripped down approach to ergonomics can work in such situations.
William H. Kincaid, P.E., CSP, is a vice president and loss control consultant with Lockton Companies, LLC.