Use of a Means-End Abstraction Hierarchy to Conceptualize the Ergonomic Design of Workplaces
Marvin J. Dainoff and Leonard S. Mark Miami University
There is now widespread international awareness of the potential problems associated with prolonged work in static postures. The United States Bureau of Labor Statistics recently estimated that so-called cumulative trauma disorders (CTD), now constitute almost half of all occupational illnesses. The term cumulative trauma refers to the presumed nature of these disorders, a kind of overuse of the musculoskeletal system resulting from prolonged work in awkward postures. Other terms used in the popular press are repetitive strain injury or repetitive motion injury. In the past, the term, CTD, has been restricted to disorders of the upper extremities (neck, shoulder, arm, wrist, hands); recently, there has been a tendency to include certain lower back problems.
The large increase in CTD rates refers, of course, to the working population as a whole. It is generally supposed that the particular workers who are most at risk for CTD are those in industrial settings in which lifting and vibration is a regular part of their work. However, a substantial fraction of these disorders are associated with static postures, in which workers are sitting for prolonged periods at video display terminals (VDTs).
A number of studies have linked VDT work with musculoskeletal disorders ( Dainoff & Dainoff, 1986). Hettinger ( 1985) examined the