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Ergonomics is about ensuring a good 'fit' between people and the things they use. People vary enormously in height and weight, in physical strength, in ability to handle information and in many other ways. Ergonomics uses information about human abilities attributes and limitations to ensure that our equipment, work and workplaces allow for these variations.
For example, a car built only for 'average' sized drivers might require larger people to crouch, while smaller people might be unable to reach the pedals. Designers use information on variations in size, reach etc to produce cars that most people can operate comfortably and conveniently. It is recognised that there must be some element of compromise where extremes of, for instance, body size are involved.
Designing tasks, equipment and workstations to suit the operator can reduce operator error, accidents and ill health. Failure to observe ergonomic principles can thus have serious repercussions, not only for individuals but also for the whole organisation. Effective use of ergonomics will make work safer, healthier and more productive.
Some of the most obvious examples are to do with body size: for instance, work stations that are uncomfortable to sit at because they don't allow enough clearance for users' legs. There is guidance available for designers and installers of equipment, to help them to avoid such problems (for example, British Standard 3044 - Guide to ergonomic principles in the design and selection of office furniture).
Many hand tools require a very wide grip. Such tools can impose severe strain if used frequently, particularly for people with small hands. The handles to tools with a hand span, such as pliers, should be between 50 mm and 67 mm apart, for the user to exert the necessary force with maximum efficiency.
High hand forces should be avoided where possible and handles should be designed so that they do not dig into the palm but spread the load over the largest possible area. Ergonomically designed hand tools can reduce injuries and increase productivity.
The layout of controls and displays can influence the safety of a system. Typical problems include control panel layouts that are difficult to understand and displays that force the user to bend or stretch to read them properly.
Systematic analysis of how people actually use equipment can highlight problems that need to be designed out. This underlines the importance of manufacturers, designers and installers applying ergonomic principles.
The people who do a particular job are in a good position to identify especially awkward or difficult tasks, but remember that they may have become used to poor design over time. Some jobs may be known to be excessively tiring, or liable to cause aches and pains. Makeshift adaptations to machines for example lengthened levers; extra labels on switches, blocks of wood or cushions used to alter working positions can be an indication that the design of the equipment or the job needs attention. Similarly, medical and absence records may reveal patterns of injury or complaint that could be association with particular jobs or task.
A minor alteration may be all that is necessary to make a task easier and safer to perform. Always make sure that any alterations are properly evaluated by the people who do the job and be careful that a change introduced to solve one problem does not cause difficulties elsewhere. Where a straightforward solution does not seem possible, and radical redesign seems to be called for, you should consult the appropriate experts.

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