How safe are you when using your computer

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A Guide for Pupils and Students

• How safe are you when using your computer?

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Is your computer out to harm you?

• No! is the simple answer
• however, you can harm yourself from careless use
  of computers

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Computers can cause injury and harm health if
your

• posture is bad and
• you work without a break and
• you use them too much.

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It is the mixture of hazards

• bad posture, and
• long sessions, and
• too much use

that can lead to harm.
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Getting the right posture Step 1 Adjusting the
chair height

• Elbow level with top of keyboard

• Upper arm vertical or forward by 5?

• Fingertips just above the home row of the keyboard

• Forearms and hands horizontal

• Elbows with right-angle bends

• Elbows tucked in at the side

• Adjust your seat height to allow all of the above

Dos and Donts
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Getting the right postureStep 2 Adjusting the
backrest

• Sit back in the chair

• The spine should be curved in at the back

• Adjust the backrest height to support the small
  of the back

• Sit erect, or lean slightly back by about 5?
  letting the backrest support some of your weight

Dos and Donts
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Getting the right postureStep 3 Legs and feet

• Sit with thighs horizontal, not letting them
  support the weight of the body

• The lower legs should be vertical

• The knee joint should have a right-angle bend

• Feet should be flat on the floor, or resting on
  a footrest

Dos and Donts
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Getting the right postureStep 4 Head and
shoulders

• The shoulders should be relaxed

• Slouching should be avoided

• The head should be kept up, but the screen must
  not be above eye level

Dos and Donts
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Getting the right postureStep 5 Position of
keyboard screen

• Both the keyboard and screen should be directly
  in front of you not to one side

• You should not have to twist either your body or
  neck to use the keyboard or to look at the screen

Dos and Donts
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Getting the right postureStep 6 Setting the
screen height

• Ideally the top of the screen should be just
  below eye level (but it must not be above eye
  level)
• The normal height of a laptop screen is also
  satisfactory

Dos and Donts
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Getting the right postureStep 7 Setting the
screen distance

• The viewing distance should lie between 0.45 and
  0.75 metres
• The display screen should be moved back or
  forward to give comfortable viewing
• A viewing distance of 0.6 metres is about right
  for most

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Getting the right postureStep 8 Setting the
keyboard position

• The keyboard should be about 10 cm back from the
  front edge of the desk giving your hands space to
  rest
• The keyboard should be parallel to the edge of
  the desk
• The letters H and K in the home row should be in
  front of you and in the centre
• The use of a palm-rest between the edge of the
  desk and front of the keyboard is recommended

Dos and Donts
Workstations with 2 users
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Getting the right postureStep 9 Setting the
screen angle

• Screen glare should be avoided because it can
  cause you to
• twist your head and body, or
• crane your neck forward, or
• get into other bad posture positions in order to
  read the screen.
• If there is glare,
• swivel or tilt the screen to remove the unwanted
  reflection, or
• close the blinds

Dos and Donts
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Getting the right postureStep 10 Using a mouse

• Position the mouse very close to the edge of the
  keyboard and about 10 cm from the front edge of
  the desk (a mini-keyboard brings the arm closer
  to a neutral posture, so reducing the tension on
  your arm and shoulder)

Mini-keyboard

• You should not have to stretch to reach the mouse
  and your arm and wrist should not be bent
  outwards away from the keyboard

• If lots of mousing is necessary, the keyboard
  should be shifted aside and the mouse placed
  directly in front of you

Dos and Donts
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Getting the right postureStep 11 Stop using the
mouse

• Try not to use the mouse too much
• Use keyboard commands in place of drop-down menu
  instructions e.g.
• Ctrl B for Bold Text
• Ctrl I for Italic Text
• Ctrl C For Copy then Ctrl V to Paste
• CtrlFunction Key(3) for ALTERING CASE
• Ctrl S Save the current file

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Getting the right postureStep 12 Document
holder

• Paperwork should be placed in a document holder
  so that it is below or alongside the screen
• You should not have to continually twist the back
  or neck to read documents

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Getting the right postureStep 13 Neutral posture

• You should try to keep the body relaxed in a
  neutral posture with very little strain on any
  muscles
• Too much stretching, twisting or bending can harm
  you, especially if repeated day after day

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Taking breaks

• You should be take a break of at least 10 minutes
  every hour
• Take suitable physical exercise during breaks
• Every so often, you should gaze outdoors,
  focusing on something distant (this allows the
  eyes to relax)

Dos and Donts
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Over-use

• If you use a computer a lot, then you must
• take hourly breaks, and
• sit with correct posture.

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Workstations with two users

• Minimum
• recommended
• table dimensions
• 1.5-1.8 metres wide
• by 0.750 metres deep
• You should sit directly in front of the keyboard
  and mouse (Step 8). The second person sits to one
  side.
• Tilt the screen so that you can both see it.
• Back to Step 8 Setting the keyboard position

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Laptops

• Set up a laptop on a table or desk as specified
  for a desktop computer
• Adjust your chair for good posture

Dos and Donts
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Dos and Donts

• Dont sit with your elbows far from your sides
• Dont extend the upper arm
• Dont flex your wrists by more than 15?
• Do keep your forearms horizontal
• Back to Step 1 Adjusting the chair height

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Dos and Donts

• Dont slouch forward
• Dont lean back
• Do sit up straight
• Do let the backrest support some of your weight
• Back to Step 2 Adjusting the backrest
• Back to Step 4 Head and shoulders

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Dos and Donts

• Dont sit on the edge of your seat
• Dont let your thighs support your weight
• Do sit back in your seat
• Do place your feet on the floor, or on a footrest
  
• Back to Step 3 Legs and Feet

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Dos and Donts

• Dont place the keyboard at an angle to the desk
• Dont sit to one side of the keyboard
• Dont sit to one side of the screen
• Do sit directly on front of the keyboard and
  screen
• Back to Step 5 Position of keyboard screen
• Workstation with two users

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Dos and Donts

• Dont place the mouse far back from the front
  edge of the desk stretching causes unnecessary
  tension in the muscles of the shoulder and upper
  arm
• Dont place the mouse far out to one side
  rotating the arm causes unnecessary tension in
  the muscles of the shoulder and upper arm
• Do place the mouse next to the side of the
  keyboard about 10 cm from the front edge of the
  desk
• Back to Step 10 Using a mouse

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Dos and Donts

• Dont place the top of the screen above eye level
• Do sit with the top of the screen at eye level
• Or do sit with it 50 mm below eye level
• Or do sit with the centre of the screen at 35?
  below eye level
• Back to Step 6 Setting the screen height

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Dos and Donts

• Dont sit with a laptop on your lap
• Dont use a laptop on the floor
• Dont use a laptop on a low table
• Do set up your laptop as you should a desktop
• Back to Laptops

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Dos and Donts

• Dont peer at the screen if the image is hard to
  see
• Do swivel or tilt the screen to remove glare
• Do close a blind to block out the sun or sky
• Do clean the screen if dusty or smudged
• Do magnify the image or increase the font size
• Do adjust the screen brightness or contrast
• Back to Step 9 Setting the screen angle

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Dos and Donts

• Dont work without a break
• Do take a break of at least 10 minutes every hour
• Do take some exercise
• Do look away from the screen from time to time,
  letting your eyes focus on something distant
• Back to Taking breaks

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Summary

• Set up your workstation using all the rules on
  good posture
• Do take regular breaks, especially with exercise
• Dont use computers for extended periods.

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It is the mixture of hazards

• bad posture, and
• long sessions, and
• too much use

that can lead to harm.
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Index of pages on this Powerpoint
How safe are you when using your computer? A
Safety Guide for Pupils and Students

• Intro - how safe are you when using your
  computer?
• Is your computer out to harm you?
• Computers can cause injury and harm health if
  your
• Steps to getting the right posture -
• 1 Adjusting the chair height
• 2 Adjusting the backrest
• 3 Legs and feet
• 4 Head and shoulders
• 5 Position of keyboard screen
• 6 Setting the screen height
• 7 Setting the screen distance
• 8 Setting the keyboard position
• 9 Setting the screen angle
• 10 Using a mouse
• 11 Stop using the mouse
• 12 Document holder
• 13 Neutral posture

Taking breaks Over-use Workstations with two
users Laptops Dos and Donts related to steps
in getting the right posture etc. - Step 1
Adjusting the chair height Step 2 Adjusting the
backrest Step 4 Head and shoulders Step 3 Legs
and Feet Step 5 Position of keyboard
screen Step 10 Using a mouse Step 6 Setting the
screen height Laptops Step 9 Setting the screen
angle Taking breaks Summary