Disciplines Contributing to Physical Ergonomics
As noted earlier, ergonomics is inherently a multidisciplinary field. Indeed, it can be argued that ergonomics is essentially the intersection of several more primary fields, both receiving basic information from them and providing applications, tools, and procedures to them. Among the primary disciplines contributing to ergonomics and in which the ergonomist must have a fair degree of knowledge are anatomy, physiology, and mechanics. As will be seen in the subsequent presentation of methods, all are needed at some level to adequately address the measurement and matching problems earlier noted.
Ergonomics in the Design Process
Where are ergonomists and how do they contribute to the design process? As with any profession, the answer is necessarily diverse. In smaller enterprises, if any individual has responsibility for ergonomics, it is often along with safety and other related topics. In larger enterprises, there may be one or more persons with specific ergonomics training and expertise. In the largest, such as automotive manufacturers, whole departments may exist. Ergonomics consultants are also widely employed, as are ergonomists in academic centers.
Methods by which ergonomics is part of the design process are similarly quite varied. Broadly, ergonomics in design is either proactive or reactive. In the former, procedures such as those described below are applied early in a product or process life cycle, such as in the conceptual or prototype phases. In reactive situations, ergonomics methods are employed only after a design problem has been identified (e.g., a control cannot be reached, required torques cannot be generated, or work-related injuries are prevalent).
A natural question arises as to the need for ergonomics in design. Justification comes from a range of documented case studies, formal experiments, and economic evaluations. Though somewhat oversimplified, ergonomic design attempts to optimize design by minimizing adverse physical consequences and maximizing productivity or efficiency. It should be noted that these goals are at times in conflict, but ergonomic methods provide the tools whereby an optimal balance can be achieved.
An important justification for ergonomics is provided by the high costs of mismatches between demands and capabilities. Occupational musculoskeletal illnesses and injuries (e.g., sprains, strains, low-back pain, carpal tunnel syndrome) result in tens of billions of dollars (U.S.) in worker compensation claims, additional costs related to worker absenteeism and turnover, and unnecessary human pain and suffering. Increasingly, there are legal requirements and expectations for ergonomics in design (e.g., national standards or collective bargaining contracts). With respect to economics, it has been well documented (e.g., Refs. 3 and 4) that occupational ergonomic programs have led to reductions in overall injuries and illnesses and work days missed, with concurrent improvements in morale, productivity, and work quality. Further, ergonomic controls usually require small to moderate levels of investment and resources and do not drastically change jobs, tasks, or operations.
Maury A. Nussbaum
Industrial and Systems Engineering
Virginia Polytechnic Institute and State University
Blacksburg, Virginia
Jaap H. van Diee¨n
Faculty of Human Movement Sciences
Vrije Universiteit
Amsterdam, The Netherlands
Mechanical Engineers’ Handbook: Materials and Mechanical Design, Volume 1, Third Edition.
Edited by Myer Kutz
Copyright 2006 by John Wiley & Sons, Inc.
