ergonomics

ergonomics Why is the video recorder one of the most frustrating domestic items to operate? Why do some car seats leave you aching after a long journey? Why do some computer work-stations confer eye strain and muscle fatigue? Such human irritations and inconveniences are not inevitable — ergonomics is an approach which puts human needs and capabilities at the focus of designing technological systems. The aim is to ensure that humans and technology work in complete harmony, with the equipment and tasks aligned to human characteristics.

Ergonomics has wide application to everyday domestic situations, but there are even more significant implications for efficiency, productivity, safety, and health in work settings. For example:(i) Designing equipment and systems, including computers, so that they are easier to use and less likely to lead to errors in operation — particularly important in high stress and safety-critical operations such as control rooms.(ii) Designing tasks and jobs so that they are effective and take account of human needs such as rest breaks and sensible shift patterns, as well as other factors such as the intrinsic rewards of work itself.(iii) Designing equipment and work arrangements to improve working posture and ease the load on the body, thus reducing instances of Repetitive Strain Injury/Work Related Upper Limb Disorder.(iv) Information design, to make the interpretation and use of handbooks, signs, and displays easier and less error-prone.(v) Design of training arrangements to cover all significant aspects of the job concerned and to take account of human learning requirements.(vi) The design of military and space equipment and systems — an extreme case of demands on the human being.(vii) Designing working environments, including lighting and heating, to suit the needs of the users and the tasks performed. Where necessary, design of personal protective equipment for work in hostile environments.(viii) In developing countries, the acceptability and effectiveness of even fairly basic technology can be significantly enhanced.The multi-disciplinary nature of ergonomics (sometimes called ‘Human Factors’) is immediately obvious. The ergonomist works in teams which may involve a variety of other professions: design engineers, production engineers, industrial designers, computer specialists, industrial physicians, health and safety practitioners, and specialists in human resources. The overall aim is to ensure that our knowledge of human characteristics is brought to bear on practical problems of people at work and in leisure. We know that, in many cases, humans can adapt to unsuitable conditions, but such adaptation leads often to inefficiency, errors, unacceptable stress, and physical or mental cost.

The components of ergonomics

Ergonomics deals with the interaction of technological and work situations with the human being. The basic human sciences involved are anatomy, physiology, and psychology. These sciences are applied by the ergonomist towards two objectives: the most productive use of human capabilities, and the maintenance of human health and well-being. In a phrase, ‘the job must fit the person’ in all respects, and the work situation should not compromise human capabilities and limitations.

The contribution of basic anatomy lies in improving the physical ‘fit’ between people and the things they use, ranging from hand tools to aircraft cockpit design. Achieving good physical fit is no mean feat when one considers the range in human body sizes across the population. The science of anthropometrics provides data on dimensions of the human body, in various postures. Biomechanics considers the operation of the muscles and limbs, and ensures that working postures are beneficial, and that excessive forces are avoided.

Our knowledge of human physiology supports two main technical areas. Work physiology addresses the energy requirements of the body, and sets standards for acceptable physical work-rate and workload, and for nutrition requirements. Environmental physiology analyses the impact of physical working conditions — thermal, noise and vibration, and lighting — and sets the optimum requirements for these.

Psychology is concerned with human information processing and decision-making capabilities. In simple terms, this can be seen as aiding the cognitive ‘fit’ between people and the things they use. Relevant topics are sensory processes, perception, long- and short-term memory, decision making, and action. There is also a strong thread of organizational psychology.

The importance of the psychological dimension of ergonomics should not be underestimated in today's ‘high-tech’ world — remember the video recorder example at the beginning. The ergonomist advises on the design of interfaces between people and computers (Human Computer Interaction or HCI), information displays for industrial processes, the planning of training materials, and the design of human tasks and jobs. The concept of ‘information overload’ is familiar in many current jobs. Paradoxically, increasing automation, while dispensing with human involvement in routine operations, frequently increases the mental demands in terms of monitoring, supervision, and maintenance.

The ergonomics approach — understanding tasks … and the users

Underlying all ergonomics work is careful analysis of human activity. The ergonomist must understand all of the demands being made on the person, and the likely effects of any changes to these — the techniques which enable him to do this come under the portmanteau label of ‘job and task analysis’.

The second key ingredient is to understand the users. For example, ‘consumer ergonomics’ covers applications to the wider contexts of the home and leisure. In these non-work situations the need to allow for human variability is at its greatest — the people involved have a very wide range of capabilities and limitations (including the disabled and elderly), and seldom have any selection or training for the tasks which face them.

This commitment to ‘human-centred design’ is an essential ‘humanizing’ influence on contemporary rapid developments in technology, in contexts ranging from the domestic to all types of industry.

David Whitfield, and Joe Langford

Bibliography

Kroemer, K. (1997). Fitting the task to the human, (5th edn). Taylor and Francis, London.
Norman, D. A. (1988). The psychology of everyday things. Basic Books Inc., New York. (Reprinted in paperback as The design of everyday things. Doubleday, New York, 1990.)