Application of ergonomics to physiological problems

Physiology is about the way the body functions.

Physiological problems occur when the body is required to do too much work, to work awkwardly or to work under bad environmental conditions.

Fatigue results from most work. The worker should be not more than healthily tired at the end of his working day. Thus the rest allowances built into the task should be adequate without being excessive and uneconomic. Ergonomists assess physical work by measuring oxygen breathed, heart rate change etc, but are usually handicapped by only being able to measure individuals under semi-natural conditions.

However, in a similar way they can measure recovery from fatigue. This has a direct connection with rest allowances; for instance, it has been confirmed that although learners need more rest than qualified workers, they are apt to tire themselves out by not resting adequately during the early part of their work. There is a natural balance between work periods and rest periods for every day whereby quality and quantity of work are at an optimum. This is not yet being adequately exploited by the employment of industrial ergonomists at the actual workplace.

Work measurement, in management services, involves rating for effort. A worker on piecework performs at 25 per cent more output than on day rate, and a work study person can assess within fairly close limits the rate at which an operator is working.

In the past there have been many attempts at using ergonomics to measure effort more accurately; unfortunately such successes as have been achieved in the laboratory tended not to have been repeated in the rigors of the actual workplace. But with the transistorized miniaturization of equipment now available, improved accuracy of shopfloor studies will increase substantially, eventually leading to the point where rates can easily be set by using simple standard physiological measuring equipment.

In jobs where anatomical restrictions result in postural difficulties, extra physiological effort and fatigue occur. Often work is aided by using momentum from part of the body, and the value of this depends on exactly how it is done. Performed inexpertly it can result in permanent damage to the back. By assessing the effect on the affected muscle groups, ergonomists can determine which of several postures is less fatiguing and make recommendations of how to improve matters at least cost.

The physiological effects of environmental factors have been traditionally catered for by increased rest allowances. Ergonomists have shown this practice to be erroneous; it now contravenes health and safety legislation. Actually by giving workers an increased rest allowance, indirectly translatable into cash, vulgarly but accurately called 'dirt money', management formally acknowledges the health hazard by bribing the worker not to make a fuss about it. Thus there is cause for saying that both management and workforce become liable to prosecution where poor environments are compensated for in increased wages, however sophisticated the payment system may appear.

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