1. A Guide for Pupils and Students
How safe are you when using your computer?
A Guide for Pupils and Students

2. Is your computer out to harm you?
No! – is the simple answer
however, you can harm yourself from careless use of computers

3. Computers can cause injury and harm health if your:
posture is bad; and
you work without a break; and
you use them too much.

4. It is the mixture of hazards
bad posture, and
long sessions, and
too much use
… that can lead to harm.

5. 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 Don’ts

6. Getting the right posture Step 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 Don’ts

7. Getting the right posture Step 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 Don’ts

8. Getting the right posture Step 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 Don’ts

9. Getting the right posture Step 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 Don’ts

10. Getting the right posture Step 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 Don’ts

11. Getting the right posture Step 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

12. Getting the right posture Step 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
Workstations with 2 users
Dos and Don’ts

13. Getting the right posture Step 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 Don’ts

14. Getting the right posture Step 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 Don’ts

15. Getting the right posture Step 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
Ctrl+Function Key(3) – for ALTERING CASE
Ctrl S – Save the current file

16. Getting the right posture Step 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

17. Getting the right posture Step 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

18. 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 Don’ts

19. If you use a computer a lot, then you must:
Over-use
If you use a computer a lot, then you must:
take hourly breaks, and
sit with correct posture.

20. Workstations with two users
Minimum
recommended
table dimensions
metres wide
by 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

21. Laptops
Set up a laptop on a table or desk as specified for a desktop computer
Adjust your chair for good posture
Dos and Don’ts

22. Dos and Don’ts Don’t sit with your elbows far from your sides
Don’t extend the upper arm
Don’t flex your wrists by more than 15
Do keep your forearms horizontal
Back to Step 1: Adjusting the chair height

23. Dos and Don’ts Don’t slouch forward Don’t 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

24. Back to Step 3: Legs and Feet
Dos and Don’ts
Don’t sit on the edge of your seat
Don’t 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

25. Dos and Don’ts Don’t place the keyboard at an angle to the desk
Don’t sit to one side of the keyboard
Don’t 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

26. Back to Step 10: Using a mouse
Dos and Don’ts
Don’t 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
Don’t 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

27. Back to Step 6: Setting the screen height
Dos and Don’ts
Don’t 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

28. Dos and Don’ts Don’t sit with a laptop on your lap
Don’t use a laptop on the floor
Don’t use a laptop on a low table
Do set up your laptop as you should a desktop
Back to Laptops

29. Back to Step 9: Setting the screen angle
Dos and Don’ts
Don’t 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

30. Dos and Don’ts Don’t 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

31. Summary Set up your workstation using all the rules on good posture
Do take regular breaks, especially with exercise
Don’t use computers for extended periods.

32. It is the mixture of hazards
bad posture, and
long sessions, and
too much use
… that can lead to harm.

33. 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 Don’ts 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
Step 9: Setting the screen angle
Summary