Ergonomics: A Congruent Concern of Labor, Business and Government

Dr. Tom B. Leamon

Director, Liberty Mutual Research Center for Safety and Health
71 Frankland Road
Hopkinton, 01748
Phone: 508-435-9061
Fax: 508-435-8136

ABSTRACT

Ergonomics is uniquely concerned with understanding and accommodating the human limitations to performance in industrial systems. Such performance can and should be measured by system outputs, including production units, labor turnover, absenteeism, workplace health and safety and product quality. In every conceivable endeavor, inadequate accommodation of the human being in hardware and software systems brings penalties in production costs, satisfaction, safety and places a burden on society in general.

Ergonomics is indeed a multidisciplinary endeavor, in some cases the domain is very broad, ranging from the design of displays to the improvements in output and well-being resulting from the formation of autonomous work groups first established in British underground mining activities in the 1950s. However empirically, drawing boundaries is possible by examining classifications of workplace injuries and losses, and determining what discipline might be available to develop interventions and remedies. In doing so, we are faced with conflicting approaches, one, to aggregate the largest sample possible, essentially looking at "American business", and secondly to focus in on specific industries with individual problems. There is, however, no conflict, provided doctrinaire statements are avoided and an appropriate analysis is picked for the particular argument.

Currently, much of the debate focuses on the performance measure of health and safety statistics, but in practice a considerable amount of effort is being placed each day on improving workplaces to increase the productivity of the labor force, which, presumably because of the proprietary interest in such activities, is little discussed outside the high performance domain of aerospace.

Two major sources of relevant information are: data from the Bureau of Labor Statistics (BLS), and workers' compensation claims data, with its massive number of insured workers. Examination of these data has been used to address the significance and relevance of losses due to inadequate ergonomics. Several strategies have been adopted, which have become issues in themselves, and distracted attention from the basic premise that improvements in ergonomics will improve performance, including health and safety in the workplace.

For example, the practice of the Bureau of Labor Statistics (BLS) in reporting cumulative trauma as a rate per million hours worked unduly emphasizes the problem. The attempt to obfuscate the issue by including low back pain as a repetitive injury in a classification which is otherwise entirely upper extremity, diseases, and the demand for a precise value of a risk factor in a highly variable process are approaches unlikely to generate the benefits of ergonomics.

In previous work, the Liberty Mutual Research Center has attempted to classify sources of loss into the antecedent activities which resulted in the disability which was reported in the workers' compensation system. It is possible to speculate on the possible interventions for the major antecedent activities, avoiding the oxymoron of "ergonomics injuries". These interventions range from the layout of workplaces (including anthropometric needs and interface design), to the establishment of safe lifting limits reflecting worker diversity and the number of exposures; from the derivation of appropriate measure of the coefficient of friction to the design of warning signs for machine guarding; from personal protective clothing to prevent struck-against and struck-by injuries to the design of work:rest schedules.

Thus, it can be seen that a very significant proportion of losses in American workplaces are susceptible to interventions based on an understanding of ergonomics, in particular, by recognizing the human requirements, decisions can be made to accommodate individuals while reflecting the interests of output, performance and quality.

One caveat: almost all data available do not in fact indicate injuries, but rather are a count of the behaviors of a person who decides not to go to work for a particular number of days. While in the case of traumatic amputations, the decision may be very clear, in a very large proportion of other activities, the decision of whether to attend the workplace (given various degrees of discomfort or pain) is clearly modified by both psychosocial and sociotechnical moderators. The quantitative effects of these are likely to be very significant. This difference between injury and the resulting disability will be explained, and it is suggested that in the continuum from no accident to total incapacity, ergonomics interventions have a significant role in inhibiting the progression from one stage to the next. Any proposal to count symptoms, or discomfort measures, while designed to avoid injuries, will involve moderation to different degrees, and possibly even by different moderators, and be difficult to reconcile with more traditional recorded behaviors.