What does ergonomics mean? It is the study of efficiency, comfort and safety of people in their working environment. The Health and Safety in Employment Act 1992 has made many ergonomic requirements law. There are additional considerations that most responsible employers choose to put in place to ensure a safe and efficient workplace. The Department of Labour has published an approved Code of Practice for the use of Visual Display Units, covering all of the ergonomic factors that should be considered in a workplace. (See http://www.osh.govt.nz/order/catalogue/pdf/vdu-ac.pdf)

Ergonomics for computer operators covers the following areas:

Computer Furniture and Operator Posture

Chair A well designed, adjustable chair is one of the most important factors in preventing back and posture problems. Your chair should be adjustable vertically and be adjustable while you are seated. You should be able to sit with both feet on the floor and there should be no pressure against your lower back or thighs – you should be able to fit one hand-width between the seat and the back of your knee. Sit at the back of your chair, not perched on the edge.

Keyboard 

Position the keyboard directly in front of your body. Determine what section of the keyboard you use most frequently, and readjust the keyboard so that section is centred with your body

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Adjust the keyboard height so that your shoulders are relaxed, your elbows are in a slightly open position (100° to 110°), and your wrists and hands are straight

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Wrist rests can help to maintain neutral postures and pad hard surfaces. However, the wrist rest should only be used to rest the palms of the hands between keystrokes. Resting on the wrist rest while typing is not recommended. Avoid using excessively wide wrist rests, or wrist rests that are higher than the space bar of your keyboard.

Foot-rest A foot-rest is useful when the desk and chair cannot be adjusted and can be used to ensure proper posture.

Desk An important ergonomic consideration in an office is the manner in which space is used, and the furniture that is used with computer equipment. There is a huge range of desks/workstations available, providing an ergonomic work space solution for anyone. Features of ergonomically designed workstations include: 

Electrically adjustable parts

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Sit down or stand up operation

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Adjustable, tilted keyboard surfaces

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Sliding trays for keyboard and mouse

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Safe and tidy cable securing.

If the height of your chair and foot-rest are fixed then you must be able to adjust the height of your desk. The desk should be big enough to allow the keyboard, screen controls (on-off, brightness), documents, document carrier, and any other items which you use regularly (telephone, desk caddy etc) to be within easy reach. It should also be as thin as practical, ideally less than 2.5 cm to give you maximum knee room.

Computer Hardware and Equipment Monitor Incorrect positioning of the screen and source documents can result in awkward postures. Adjust the monitor and source documents so that your neck is in a neutral, relaxed position. Make sure you: 

Centre the monitor directly in front of you, above your keyboard.

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Position the top of the monitor approximately 2-3” above seated eye level.

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Sit at least an arm's length away from the screen (to avoid eye-strain and the distance for your vision.

radiation) and then adjust

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Glare When a computer monitor is located near a window or lights, glare can commonly be a problem, causing eyestrain or headaches. Reduce glare by careful positioning of the screen: 

Place screen at right angles to windows

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Adjust curtains or blinds as needed

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Adjust the vertical screen angle and screen controls to minimize the glare from overhead lights

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Adjust your monitor for maximum contrast and minimum brightness

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An anti-glare screen can be positioned over the monitor to reduce or eliminate the problem. Many antiglare screens incorporate radiation filters to protect the user from potentially harmful rays emitted by a computer monitor. New monitors are available that incorporate filters, and have flat screen technology which reduces or eliminates glare

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Blink often when using a computer to prevent dry eyes and headaches and look away from your screen often to exercise your eyes.

Radiation 

As well as using the anti-reflective or polarising filter mentioned above, you should avoid radiation by ensuring you are not seated at the side or back of other monitors around you.

Documents 

Position source documents directly in front of you, between the monitor and the keyboard, using an inline copy stand. If there is insufficient space, place source documents on a document holder positioned adjacent to the monitor.

Copy-holder 

A copy-holder makes it possible to view documents without excessive neck bending. It should be large enough to support the copy placed on it and should be stable in all positions. Position the copy-holder so it is comfortable, usually on a slight angle at the left of the screen.

Telephone 

Place your telephone within easy reach. Telephone stands or arms can help.

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Use headsets and speaker phone to eliminate cradling the handset.

Keyboard Ideally, the keyboard should allow the operator to work with his or her elbows at a 90 angle. The following steps can reduce strain on the hands and wrists: 

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Key in gently—don’t pound the keys. Pounding sends shockwaves up the arms that can create or aggravate problems with the fingers, wrists and arms

Don’t over-reach when reaching for the function keys. This causes the finger tendons to stretch. Move your hand closer to the desired key before pressing it.

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There are now many different designs of keyboard available, depending on personal preference, where and how the keyboard will be used, and what ergonomic considerations need to be taken into account for an individual.

Mouse Place your hand so it rests on the mouse with your index finger resting on the left mouse button, your middle finger resting on the right mouse button and remaining two fingers at the right of the mouse. The mouse is positioned at the right or left of the keyboard. Be careful not to tightly grip the mouse for long periods—relax this hand at every opportunity. There is now a huge range of mouse designs available to fit comfortably into large and small hands, and left and right.

Workstation and Equipment Layout Suggested Layouts A workstation should be set up so that frequently-used items are within easy reach. Two possible layouts recommended in the Department of Labour Code of Practice are shown below. Everything needs to be within easy reach of the person sitting working Localised lighting Localised lighting

Printer

Reference Docs

Telephone

Telephone

Perso n

Monitor

Inbox

Keyboard

Files

Keyboard

Perso n

Inbox

Monitor

Document Holder

Document Holder Files

The aim in both scenarios is that the person sitting working can reach their telephone, monitor, documents, inbox, printer and keyboard without having to continually stretch uncomfortably in a way that could cause occupational overuse syndrome (OOS) or repetitive stress injury (RSI). Note too that The Code of Practice recommends reducing exposure to magnetic fields by keeping the monitor and printer at arm’s length.

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Good Operator Habits RSI and OOS Occupational overuse syndrome (OOS) and repetitive strain injury (RSI) are collective terms for a range of conditions, including injury, characterised by discomfort or pain in the muscles, tendons and other soft tissues, with or without physical signs. Symptoms can include: 

Fatigue

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Stiffness

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A burning sensation

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Soreness

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Aches and pains

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Numbness and tingling.

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Weakness in muscles, discomfort

Poor planning for computer work tasks (ie doing too many uninterrupted hours of direct entry)

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Inappropriate selection of office furniture

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An inappropriate VDU environment (see monitor notes)

Poor work organisation

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Poor workstation layout

Inappropriate selection of computer hardware and software

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Lack of education, training and skills.

The risk factors for OOS or RSI can be summarised as: 

It is important that steps be taken to prevent these health problems from occurring. Repetitive tasks should be minimised and work breaks taken regularly. Exercises should be used to stimulate blood flow – to help reverse the effects of muscle tension – and help you to relax. Ensure that your posture is correct at all times and report any aches and pains promptly so that they can be dealt with before they become severe or chronic.

Work Breaks Once you have correctly set up your computer workstation, use good work habits. No matter how perfect the environment, prolonged, static postures will inhibit blood circulation and take a toll on your body. 

Take short 1-2 minute stretch breaks every 20-30 minutes. After each hour of work, take a break or change tasks for at least 5-10 minutes. Always try to get away from your computer during lunch breaks

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Avoid eye fatigue by resting and refocusing your eyes periodically. Look away from the monitor and focus on something in the distance

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Rest your eyes by covering them with your palms for 10-15 seconds

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Use correct posture when working. Keep moving as much as possible.

Micropauses and Macropauses A micropause is a short break in work for muscle relaxation - specifically, it is a 5-10 second break every three minutes or so. Micropauses allow for the restoration of blood flow to muscles which have been held tense and it is when the muscles relax fully that micropauses are of most value. Micropauses help you to be more productive. A macropause is a five minute break approximately every hour to move around and have a complete break from computer work. Both types of breaks are essential to maintain the health and safety of the operator.

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Physical Exercises There are many exercises that you can do at regular intervals during the day to stimulate blood flow and reduce muscle tension (a real enemy of computer users). Exercises recommended by the Department of Labour’s Code of Practice: Exercise 4—Forearm Turns Exercise 1—Arm Shakes Sometimes our work causes us to hold some Let your shoulders go loose and shake your whole muscles short and tight. These need gentle arm(s), holding your arms straight up and down. lengthening. Exercise 2—Wrist Flaps/Forearm Turns Straighten your arms; hold them down by your Let your wrists go loose, move your arms back thighs, both ways, turning inwards and outwards. and forth to make your hands flap, bending Hold for a few seconds at the extremes. loosely at your wrists. Exercise 5—Hands and Fingers Exercise 3—Shoulder Rolls With the forearms rested, and hands out in front In a relaxed manner, circle your shoulders (hold of you, turn palms up then down. the rest of your body as still as possible) so they With fingers straight, spread apart then together, describe the biggest circles possible. Let your making gaps between each finger in turn. arms hang still while your shoulders move. Do big circles in both directions. Touch each finger to thumb in turn. Repeat sliding finger tip to base of thumb. Bend wrist to 90, fingers straight – then make a fist.

Are the following statements True or False? 

You should sit as close to the monitor as possible so that you don’t have to strain to see small type

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You should use a footrest if your feet don’t reach the floor when sitting

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Short-neck monitors are for people whose chairs aren’t adjustable

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A mouse bridge helps avoid having to stretch to reach the mouse

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There is only one style of keyboard available, so you just have to get used to it

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Dropping the heels of your palms down on the front edge of the keyboard or the wrist rest while you type is a great way of relaxing at a computer

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The quickest way to get OOS in your wrists is by dropping the heels of your palms down on the front edge of the keyboard or the wrist rest while you type because it constricts the muscles while applying repeated movement.

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Office Environment Room Space In an office environment there should always be enough space for everyone to carry out their work safely. The exact amount of space, and the manner in which furniture is laid out, depends on the type of work being completed. It is also important to consider safe access to the workstation, and to other office furniture.

Décor and Lighting In order to reduce glare, rooms should be decorated in pastel shades. Blinds should be used to prevent strong sunlight from entering the room. Workstations should be located away from windows and positioned to avoid reflections. Where possible use natural light and blinds to control the light. In most offices a combination of natural and artificial light is used. Fluorescent lighting is usually standard lighting used in office situations.

Temperature and Ventilation Computers produce heat which can make your work space warmer than the rest of the office. Make sure the screen is not hard up against a wall or partition and that there is plenty of air flow around the unit. A small desk fan may be necessary if you are working in a confined space. Windows can be used for additional ventilation. The combined effects of heat and humidity can produce dryness and eye irritation. The best environment is with a relative humidity of 45% or greater. Air conditioning can lead to a dry atmosphere.

Noise People and equipment, ie printers, photocopiers, phones etc contribute to the noise factor within an office. If possible, such equipment should be placed in areas away from where people are working, to reduce noise levels.

Dust Dust can be a real enemy of computer equipment, both externally and internally. Screen cleaners are generally designed not just to clean, but to reduce static electricity and dust. Obviously, this will result in a better monitor picture, and hopefully less eye strain.

Power Points and Cables Avoid overloading power points. Double adaptors or multi-boxes (which have 3 or 4 power points) should be used, and secured safely. Ensure that cables are kept tidy and out of the way. Special desks have a cavity that encloses computer cables – an alternative is to use cable ties to bind cords together, or use special tape that can be purchased for this purpose. Long and dangling cords can cause accidents and do a lot of damage. Always take particular care with network cables as they are easily damaged.

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