Ergonomics

Conceptual Overview

Ergonomics is generally thought of as a relatively new discipline, with Hywel Murrell having played a central role in defining it in 1949. The term ergonomics, meaning the science of work, was first used in 1857 by Wojciech Jastrzebowski. It stems from the Greek ergon, meaning work, and nomos, meaning natural laws. Ergonomics draws heavily on the disciplines of psychology (cognitive, social, and organizational), anatomy, physiology, and engineering. The effectiveness of the interaction between humans and machines is affected by the degree of fit between the human operator and the machine he or she is operating. In practice, this means that the interface between the human and the machine or system, and the way the human and machine are intended to interact, should be designed to fit the human needs, rather than as a technological or aesthetic solution to an engineering problem. For example, a car designed for an average man may be virtually undrivable by a small woman. Fitting that car with seats that can vary the driving position, and a steering column that is similarly adjustable, results in a machine that is equally usable by both drivers. Within the car, the positioning, shape and feel of the controls, the design of the speedometer, and the layout of the dashboard also form part of an ergonomist's work. Infrequently used controls should be placed where they are unlikely to interfere with regular driving activities, important displays such as speed should occupy a more central position, and both controls and displays should behave as the driver would expect. These control and display issues are often seen as the core business of ergonomics; however, with the increasing range and complexity [Page 465]both of technology and of the systems of which they form a part, the scope of the discipline has widened. It now encompasses issues from crew resource management, teamwork, and communication to protective work wear and safety provision.

The user of the tool, equipment, or system is therefore at the heart of good ergonomic design. Furthermore, the user will be using the equipment in certain environmental conditions that may place a range of other demands on him or her. For example, there might be excessive noise or other task-related distractions. Some users may be very experienced and have a high level of expertise in using a system, others may be novice users with limited understanding of what is required, and there may also be a wide range of intermittent or occasional users. For example, it is reasonable to expect that a great deal of training is needed before it is possible to use the controls in the cockpit of a plane, whereas it must be possible to know immediately how to use a machine that dispenses parking tickets with no training or prior knowledge. These different users have different needs of the system, the interface, and the technology generally. The ergonomist therefore needs to consider the range of the human capabilities and expectations and also the features of the environment in which the system is operating in order to develop usable tools, machines, and jobs. Typically ergonomists consider the human-machine system, each element of which has its own strengths and limitations.

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