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What is ergonomics?
An applied science concerned with designing and arranging things people use so that the people and things interact the most efficiently and safely.
YOUR EYES AND COMPUTER
The greatest complaint expressed by computer users is chronic eye fatigue.
Close work on the computer monitor tends to cause general eye strain, dry eyes, tearing, blurred vision and temporary soreness for many people. Although it may not be possible to completely eliminate all eye discomfort, simple changes in the workstation setup can significantly reduce symptoms.
A major contributing factor to having dry, itchy eyes results from a reduction in the frequency of your eye's blink rate while viewing the monitor. The human eye cleanses and refreshes itself automatically many times per minute. However, staring and concentrating at the bright monitor causes your eye's blink rate to significantly decrease. The corneal surface dries out resulting in irritated, red, and tired eyes.
Take frequent breaks away from your computer to allow your eyes to fully relax and refresh themselves.
Another factor contributing to eye fatigue results from simple muscle exhaustion. Small muscles in the eye are responsible for changing the shape of its lens to permit close viewing. Unless there is an effort to consciously relax your eyes, these muscles build up lactic acid, fatigue, and become sore. Periodically gazing across the room or out a window will allow your eye muscles to relax and receive freshly oxygenated blood, thus reducing lactic acid. The eyes will usually recover very quickly when allowed to rest.
Computer monitors should have both a contrast and brightness control switch. Maximum contrast and minimum brightness usually produce the least strain on the eyes.
Adjust your monitor for maximum personal comfort. If characters on the screen appear to be fuzzy or out of focus, it may not be faltering vision at all. Some monitors lose their character clarity due to technical problems.
Copy stands should be placed at the same height as your monitor. This allows the eyes to more easily scan back and forth at the same focal distance, rather than looking down on the desk and then readjusting back to the monitor. This reduces unnecessary repetitive motion which causes fatigue.
Light and Glare
Light striking the screen and causing excessive glare may come from many sources in your area. Situating your monitor directly in front of a large window may create strong backlighting conditions which can result in squinting and eye strain. Conversely, computers with large windows directly behind the operator will also tend to have excessive natural glare across the screen. To alleviate both problems, place your screen parallel to windows to minimize glare.
Most monitors come equipped with a pivotal base to allow for tilting up and down and swiveling from side to side. Find the best angle with the least glare.
Fluorescent lights tend to be very white and harsh on the eyes. If your workstation has a bright light above it, place a cardboard hood over the monitor to provide shade across the screen surface. Be sure not to block the ventilation openings.
Vary your activities throughout the day so that computer work is intermittent.
Changing activities allows your eyes to rest, helping to reduce chronic strain. Altering activities also allows other muscle groups to relax and stretch.
YOUR NECK AND COMPUTERS
The average adult's head weighs about twelve pounds. It's about the same size and weight as a bowling ball. When kept balanced directly over your shoulders throughout the work session, strong muscles in the neck easily adjust and support this weight. However, when the head tilts forward or backward too far, muscles become over stretched and/or contracted causing soreness, cramping and fatigue.
Correct monitor height is essential in reducing neck strain.
The top of the screen should be level with your eyes. This allows your head to remain in an upright, balanced position. A monitor placed too low forces the head to fall forward as you view the screen. This position puts unnecessary strain on the neck muscles.
Exception - If you wear bifocals, a lower monitor will help accommodate your need to peer through the lower portion of your lens without having to tilt your head backward.
Sitting directly in front of your monitor/keyboard allows greatest relaxation and helps avoid any twisting motion in the neck muscles.
YOUR HANDS, WRISTS, ARMS AND COMPUTERS
The human body simply does not perform very well when expected to perform like a machine. Muscles, ligaments and tendons become exhausted and irritated and are more prone to possible repetitive motion injuries.
Carpal Tunnel Syndrome is commonly known as repetitive-stress disorder.
It is a serious problem affecting one or both wrists of many computer users, particularly those who engage in full-time computer work. If left untreated, Carpal Tunnel Syndrome can lead to permanent damage resulting in dysfunction and pain in your hand(s).
The carpal tunnel is a small opening in the wrist area. The large median nerve, radiating down from the arm, passes through this tunnel on route to the fingers and thumb. When the wrist is relaxed and unstressed, ample space exists for the nerve to easily slide through this narrow passage. However, repetitive movement from keying, coupled with flexed wrist positions can result in exhaustion and swelling of muscles, ligaments and tendons. The carpal tunnel's reaction to this stress is to compress inwardly putting pressure directly on the nerve. This pressure can result in impairment or loss of nervous function in the first three fingers and thumb. Early symptoms of Carpal Tunnel Syndrome include numbness, tingling or burning sensation in the fingers, hands or forearms and may progress to a loss of feeling, grip and, finally, some hand function.
Ergonomic guidelines
Maintain a straight line through the wrist
Avoid unnecessary flexing in wrists during keying activities
Fingers should extend straight out from the hand
Strike keys lightly while typing
Move the mouse using the entire hand/wrist in a straight line
Mouse should be at the same height and distance as your keyboard
There should be a 90-110 degree angle through the elbow, arms close to your body and shoulders should be relaxed
YOUR BACK, LEGS AND COMPUTERS
Of the three positions we assume during the day (standing, sitting and lying down), sitting is the most stressful. The human body is not designed to hold itself comfortably in a sedentary, seated position for extended periods of time.
Solution: Take frequent breaks away from your workstation. Walk around, stretch, and exercise. This increases your metabolism, starts the blood circulating more quickly and refreshes you mentally.
Ergonomic guidelines
Individual body size will influence the height of the work surface, keyboard, monitor and the design of the chair.
Avoid twisted positions, sit directly in front of your keyboard and monitor.
Use a good quality chair:
Lower back support
Adjustable seat height and tilt
Use a foot rest to raise knees level with hips
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