Use of display screen equipment by children:

1
Teachers Guide

• Use of display screen equipment by
  children
• Health and safety guidance for schools

2
What areas are covered?

• Using computers safely
• Guidance on setting up workstations for children
  and on how to prevent computer-related injuries

3
Computers can cause injury and harm health if

• posture is bad and
• the user works for longer than one hour at a time
  without a break and
• the computer is over-used.

4
It is thecombination of hazards

• bad posture, and
• long sessions, and
• over-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 Donts
6
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
7
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
8
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
9
Getting the right postureStep 5 Position of
keyboard screen

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

• The user should not have to twist either his or
  her body or neck to use the keyboard or look at
  the screen

Dos and Donts
10
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
11
Getting the right postureStep 7 Setting the
screen distance

• The viewing distance should lie between 450 mm
  and 750 mm
• The display screen should be moved back or
  forward to give comfortable viewing for the user
• For the typical user, a viewing distance of
  600 mm gives comfortable viewing

12
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 front edge
  of the desk
• The letters H and K in the home row should be
  centrally in front of the user
• The use of a palm-rest between the front edge of
  the desk and front of the keyboard is recommended

Workstations with 2 users
Dos and Donts
13
Getting the right postureStep 9 Setting the
screen angle

• Screen glare should be avoided because it can
  cause the user to
• twist their head and body, or
• crane their neck forward, or
• adopt other forms of bad posture 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
14
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
  the arm and shoulder)

Mini-keyboard

• The user should not have to stretch to reach the
  mouse and the 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 the user

Dos and Donts
15
Getting the right postureStep 11 Stop using the
mouse

• Mousing should be reduced as much as possible by
  using keyboard commands in place of drop-down
  menu instructions
• 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

16
Getting the right postureStep 12 Document
holder

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

17
Getting the right postureStep 13 Neutral posture

• The user should try to keep the body relaxed in a
  neutral posture with very little strain on any
  muscles
• Continual or continuous stretching, twisting or
  bending should be avoided

18
Taking breaks

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

Dos and Donts
19
Over-use

• Repeated heavy use can be dangerous unless hourly
  breaks are taken and the ideal postural
  requirements are met

20
Workstations with two users

• Minimum
• recommended
• table dimensions
• 1500-1800 mm wide
• by 750 mm deep
• One person operates the keyboard and mouse as
  directed on slide 12. The screen should be
  directly in front of this person.
• The screen is tilted to let a second person see
  it.

21
Laptops

• The laptop should be set up on a table or desk as
  specified for a desktop computer
• Line-of-sight angle lies between 20? and 50?
  below horizontal
• Eye-to-screen distance is slightly under 600 mm

Dos and Donts
22
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

23
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

24
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

25
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

26
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 100 mm from the front edge of the
  desk
• Back to Step 10 Using a mouse

27
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

28
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

29
Dos and Donts

• Dont peer at the screen if the image is obscure
• Do swivel or tilt the screen to remove glare
• Do close a blind to block out the sun or sky
• Do clean the screen
• 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 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 periodically,
  letting your eyes focus on something distant
• Back to Taking breaks

31
Summary

• Set up computer workstations using all the rules
  on good posture
• Encourage users to take regular breaks,
  especially with exercise
• Do not let computer users operate workstations
  for extended periods.