Ergonomics
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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