What is Ergonomics
The study of ergonomics is the relationship between the human body and its surrounding working environment. The aim of ergonomics is to achieve high levels of efficiency, along with optimum health, safety and comfort within this working environment. In order to accomplish this, designers test and conduct research on such areas as fatigue, stress, physiological strain. This is then incorporated into the design of equipment for human use. An example of where the science of ergonomics might be used, is in the office where ergonomically designed furniture is utilised by staff.
The desks are designed to fit the person who will be sitting at them, the chairs are adjustable in order to fit also, they might have wheels so that the operator does not have to continually stand throughout the day which is potentially fatiguing over a long period of time.
The use of ergonomics is not strictly confined to corporate use either, playground construction, motor vehicle design, the gymnasium and even the home are all areas in society in which the use of ergonomic design are being further developed.
Posture is an important aspect when looking at work environment. It is important for two reasons, being health and fatigue. Poor posture over extended periods will result in spinal, joint and muscular problems. This of course is something which should and can be avoided.
In the instance of a designing a facility, ergonomics are relevant in numerous areas. Obviously, office staff will benefit its implementation in their work environment. In addition to this however, users of the facility will benefit and indeed may even be enticed by ergonomically designed facilities. e.g: gymnasium, including weight machines, changing rooms and the entire operational layout of the facility.
There are many instances in design which emphasise comfort but are negligent in terms of health and safety. True ergonomical design should encompass all of these aspects and any others pertinent to the practical and efficient use of a system or environment etc.
Ergonomics is concerned with the relationships that exist between the human body and its physical surroundings, and how those relationships impact upon a persons health.
- If a bench is too low for a person, they will bend over, putting unnecessary strain on the back. This can result in serious back pain.
- If a seat at a desk is too high or low the arms and back may suffer undue stress.
Posture is the position or manner of bearing or holding the body; or the physical stance which the body takes.
If the body has good posture, it is holding a stance or position which is preferable -any strain or static pressure on muscles will be balanced, hence undue (and possibly damaging) forces are not being exerted upon any one part of the body more than any other.
If a static (still) unsupported posture is to be maintained for an extended period, the following equilibrium conditions need to be satisfied:
Determine the centre of gravity of the body, then draw a vertical line from that point to the ground (or floor). This line MUST pass through the body's base of support (eg. if standing -the feet; if sitting -within the four legs of a chair). If this situation does not occur, the body will fall over.
The net movement (ie. torque) each time the body moves, needs to be zero. If this situation does not occur, the body can collapse at its joints. Torque is calculated by multiplying the amount of force exerted by the distance moved. Muscles never work alone: several always work at the same time; and to maintain equilibrium, different muscles must will exert an equal amount of torque in opposite directions.
People will not stand totally stationary for long periods if allowed to act naturally : the natural stance involves frequent (though slight movements), perhaps shuffling feet or swaying back and forth. One study showed that the average stance only lasted 30 seconds before a person moved into a slightly different position.
(Refer: Ergonomics Work & Health by Pheasant -Macmillan)
Lying sideways places greater pressure on spinal discs than lying flat on the back, because the width of shoulders and hips will cause the spine to sag in the middle (ie. bend).
Similarly, a soft mattress which sags can also cause the spine to bend, placing increased pressure on the spinal discs.
(Some back pain sufferers however claim that hard beds actually accentuate their problems, which appears to be a contradiction).
Lying with legs raised will increase blood returning to the heart through the veins. This is believed to be a good position (with hips and knees flexed to around 45 degrees).
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