First, ergonomics has historically been, and will remain, a design oriented applied science. To verify this, I’ve consulted numerous definitions in the ergonomics literature, and nearly without exception, the words “design” or “engineering” are key descriptors. For popular language definitions, visit www.dictionary.com and you’ll find that, without exception, the various sources identify design or engineering as key elements in ergonomics. To understand why, we should look to the philosophical foundation for ergonomics.
Humans are at the core of the ergonomics discipline. A common viewpoint is that ergonomics is about improving the fit between humans and systems. By doing so, we will improve performance, safety, comfort, etc. From this root perspective, we have only two choices: (1) change the system to better fit the human; or (2) change the human to better fit the system (or some combination of the two). Which is more likely to make a positive, measurable, effective, long lasting impact?
Clearly, it is most effective to design and engineer systems to match or enhance human capabilities, and accommodate for human limitations. Attempting to mold people to fit poorly conceived designs will ultimately fail -- absolutely, for sure, and without a doubt. Designing an incompatibility out of a system, on the other hand, solves the problem once and for all.
I do recognize that situations exist where improving human performance by modifying the human is the right option, or even the only option.
Take professional sports, for instance. All athletes compete in some predefined event, with predefined and controlled technology and equipment, and the only option is improving the individual athlete.
The military is another example. Soldiers are put through rigorous physical and mental training to improve their ability to interact effectively with complex systems and combat duties.
Training is another example of modifying the person to fit technology. Naturally, even the best system requires operators to be trained in its proper use. However, if the system design runs contrary to human abilities and limitations, no amount of training is going to eliminate injuries, accidents, waste, inferior quality and productivity, or other critical business costs and human sufferings.
In these examples, focused training and purposeful human performance conditioning are valid, essential, and measurably effective. Stretching programs, on the other hand, are not, which brings me to the second reason I don’t accept them as an ergonomics intervention.
Certified Professional Ergonomist (CPE) Mike Wynn recently shared the results of his literature review on this subject with members of the ergoweb-L discussion list. Wynn, and my own experience and research supports this, was able to find “no evidence that stretching exercises are successful in reducing work-related MSD metrics.” Further, there appears to be a similar lack of evidence that stretching is effective in reducing sports injuries, which is often cited by health professionals as the rationale for workplace stretching programs. Wynn’s research showed that most of the evidence put forth by purveyors of stretching programs is anecdotal, appearing in trade magazines rather than peer reviewed publications. Even in many of those articles, the evidence for improvements supports engineering and administrative controls, not necessarily stretching programs.
Wynn goes on to say, “the most troubling aspect of the stretching program debate is that there is ample evidence that these approaches are costly, potentially harmful, and ineffective in reducing work-related MSDs.” He cites one peer reviewed study that reviewed 127 different stretching exercises for computer users and found that 90% have health contra-indications, and 38% present safety hazards.
To be fair, stretching might be used as one small part of an overall occupational ergonomics program. And, in some cases it might actually reduce or postpone an injury or two in a poorly designed job. In addition, some make the point that exercise programs can help build “team spirit.” However, given limited resources to invest in ergonomics, you’re much better off putting your money into more effective engineering and administrative controls.
Stretching programs are better thought of as "wellness" or medical management approaches. Medical management is one of 6 program elements suggested by OSHA in their attempts to regulate the occurrence of musculoskeletal disorders (MSDs).
Stretching isn’t ergonomics; it’s therapy. Therapy is needed when ergonomics is ignored; therapy should not be considered a substitute for ergonomics.
For additional comments on this subject, see the "Related Articles" section, below.