Occupational health and safety for computer users

Introduction

It is important to use good health and safety practices while working at your computer. These practices include regular exercise and the correct setting up of your workstation, lighting and power access.

Constant use of the mouse and repetitive keyboard activity can contribute to injuries associated with occupational overuse syndrome.

This section on Occupational health and safety for computer users will provide you with some excellent tips on how to use your computer safely and comfortably.

Click on any one of the links below for more information.

1. What regular exercise can you do?

2. Where do you place your monitor for the best lighting?

3. How can you minimise eyestrain?

4. What is the correct way to access the power supply?

5. How do you set up your workstation?

6. How do you minimise fatigue and strain when using a keyboard?

7. Checklist

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What regular exercise can you do?

By performing simple exercises, you can minimise muscle strain and stress associated with prolonged keyboard use. It is recommended that you:

• Exercise a few times every day.

• Relax and perform the exercises gently.

• Avoid over-stretching.

• Always stop if you feel discomfort when doing the exercises.

• Do the exercise for each side of your body.

Neck exercises

Gently lower your ear to your shoulder and hold it there for 10 seconds. Then slowly roll your chin along your chest and up to the other shoulder and hold for 10 seconds. Repeat this several times.

Turn your head and look over your left shoulder, and hold for 10 seconds. Turn your head the other way and hold for 10 seconds. Repeat this several times.

Raise your head to straighten your neck. Then create a double chin by tucking your chin in and outwards. Your head should tilt forward. Hold for 10 seconds and repeat several times.

Circle your shoulders forward a few times, then backwards. Repeat this process three to five times.

Stretch your arm over your head and cradle your elbow with your other hand. Then gently pull your elbow behind your head. Hold for 10 seconds and repeat a few times.

Wrist, hands and arms exercises

Interlace your fingers with your palms facing outwards, then straighten your arms. Hold for 10 seconds and repeat several times.

Rest your forearms and turn your palms up and down.

Spread your fingers apart, then move them together again. Repeat this several times.

Touch your finger to your thumb and slide the fingertip to the base of your thumb. Repeat this process for each finger.

Bend your wrists to 90° with your fingers straight, then slowly make a fist.

Upper and lower back exercises

Interlace your fingers and turn your palms upwards over your head. Straighten your arms slowly and lean slightly from side to side. Repeat this several times.

While standing, support your lower back with your hands and gently arch your back and hold for 5 to 10 seconds. Repeat as often as needed.

Leg exercises

Hold on to your chair with hands on either side. Straighten your leg and lift your foot a few centimetres from the floor. Rotate your foot and ankle both ways with toes pointed up, and extend with toes pointed down. Repeat a few times with each foot.

Eye exercises

Sit upright and face forward. Look up, then down. Look left, then right. Repeat this several times without moving your head.

Look up and away from the screen and focus on a distant object (more than three metres from you) such as a picture or out the window.

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Where do you place your monitor for the best lighting?

You should be wary of the lighting surrounding your computer monitor (screen) as it can affect your eyes and the visibility of work viewed on the computer screen.

• Avoid reflections by placing the monitor to the side of the light source/s, not directly underneath.

• Try to place desks between rows of lights.

• If the lighting is fluorescent strip lighting, the sides of the desks should be parallel with the lights.

• Try not to put the monitor near a window. If this is unavoidable ensure that neither the monitor nor the operator faces the window.

• If the monitor is well away from windows, there are no other sources of bright light and prolonged desk-work is the norm, use a low level of service light of 300 lux (lux is a unit of measurement for light).

• If there are strongly contrasting light levels, then a moderate level of lighting of 400 to 500 lux may be desirable. High quality, anti-glare screens may be necessary.

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How can you minimise eyestrain?

Working constantly with computer monitors or visual display units (VDU's) can produce tired and sore eyes and eye strain.

Tip: To reduce strain, take short rests and look into the middle distance. If necessary, close your eyes and lightly cover them with your hands, then breathe deeply eight or nine times.

Colourful posters and plants will also help provide relief from eye strain.

Remember that you should also do eye exercises to minimise eye strain.

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What is the correct way to access the power supply?

Double adaptors

When there are not enough powerpoints in your office, double adaptors are often used to overcome this problem.

A double adaptor does allow you to plug in two devices. However, 'piggybacking' double adaptors is extremely dangerous and should be avoided.

When you require extra powerpoints, it is safer to use a powerboard (consisting of 3 or 4 extra powerpoints) with a surge protector rather than use 2 or 3 double adaptors to create the same number of powerpoints.

Cluttered wiring

Wiring from computers or telephones can become dangerous if there are a lot of devices in the same area.

As well as being cluttered and untidy, other potential problems are:

• It is difficult to identify which plug belongs to each device.

• When disconnecting a device to remove it for repair, replacement or relocation, it is more difficult to unplug its power cable.

• Whilst untangling power cables you could pull out the wrong plug.

To avoid these problems you should use cable ties to bind cords together and keep them neat and out of the way.

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How do you set up your workstation?

There are many ways you can minimise the potential risks associated with prolonged use of computers or keyboards. Click on the labels to read more about what you should do.

Chair Adjustable chairs will improve your body position, improve your blood circulation, reduce muscular effort and decrease pressure on your back. Make sure that your chair is adjusted to suit your requirements (a gas lift chair is best for this). Your back should be straight and your feet should be flat on the floor or on a footrest. Chairs should: have an adjustable seat height have an adjustable backrest to support the small of your back have an adjustable tilt swivel have five wheels for stability use breathable fabric on the seat. If the seat of your chair has an adjustable tilt, tilt it so that you are comfortable when using the keyboard. Usually this will be close to horizontal, but tilted slightly forwards. If this places an uncomfortable strain on your leg muscles or your feet do not reach the floor, then use a footrest. Posture and movement You should change your posture at frequent intervals to minimise fatigue. You should avoid awkward postures which strain or twist your joints, especially your wrists. Keyboard placement You should keep your forearms close to horizontal and your wrists straight - that is, each hand should be in line with the forearm. If this causes your elbows to stick out away from the side of your body, you should re-check the height of the work surface. Screen placement Your computer screen should be within an arm's length (approximately 50 cm) of your face. This should allow you to focus on the screen easily. Set the height of the monitor so that the top of the screen is below eye level (the optimum viewing angle is 38° below the horizontal), and the bottom of the screen can be read without having to incline your head. This usually means that the centre of the screen will be near shoulder height. Work surface height Your elbows should be level with the desk height, in line with your keyboard. There should be sufficient clearance under the work surface for your thighs not to be compressed. Desk layout Keep everything that you use regularly close by to avoid twisting or straining to reach them. Document holder Place your document holder close to the computer screen to lessen twisting or inclination of your head. Your document holder, computer screen and keyboard should all be at the same viewing distance.

 

 

 

 

 

 

 

 

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How do you minimise fatigue and strain when using a keyboard?

Keyboards are frequently used in today's work environments and the strain and fatigue that can occur during extensive keyboard activity should be addressed. Relieve fatigue and strain by:

• Changing posture for a little while.

• Increasing your work rate gradually, particularly when you start work each day.

• Taking frequent short breaks for a few minutes every half hour. During this break, you should walk around and perform whatever movement relieves the feeling of muscle fatigue. Movements that are a natural response to fatigued muscles such as shrugging the shoulders are generally the most effective in dealing with the fatigue.

Shrug your shoulders

Stretch your arms

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Checklist

Use this checklist to make sure that you have adjusted your work area to suit you.

Does your work area provide enough space for you to work comfortably? Is the QWERTY keyboard centred in front of you? Is it positioned approximately 2.5 cm from the edge of the desk? Is the keyboard tilt adjusted for your comfort? Can you reach out your arm and just touch the monitor? Is the top of your screen at or slightly below eye level? Is the brightness and contrast correct for you? Is your screen clean? Does your chair have a five star base with castors attached? Can your chair be adjusted? Is your chair adjusted to the correct height for you? Is your backrest positioned to give your back support? Do your feet sit flat on the floor or on a footstool? Are your elbows at right angles to your body? Are your wrists straight while you use the keyboard? Do you have access to a document holder? Is your mouse close to the side of the keyboard? Is everything you need within easy reach?

Congratulations, you have now finished all the topics in the Into the Internet online tutorial. Well done.

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