Danger: computer in use
Since the present generation of children is the first to have worked extensively with display screen equipment, and medical evidence is now emerging of injuries to children, teachers have been told that it would be "more than prudent" to take a precautionary approach.
The warnings come from the Scottish Schools Equipment Research Centre which has published new health and safety guidance on how to ensure pupils do not suffer pain or even disability through a combination of bad working practices and overuse.
Extended use of the mouse has been identified in particular as a potential cause of many injuries, the guidance warns.
While there is as yet no significant published research data giving clear evidence of injuries to children linked to computer use, the centre states that there are many reports from doctors and anecdotal evidence that children are suffering severe computer-related injuries.
Teachers are told: "You are urged to take a precautionary approach because, by their very childishness, children need cared for. They may be more prone to musculoskeletal disorders or back pain because their bodies are still growing and because they can often be quite casual about posture."
Other potential health risks are eyestrain, headaches, tiredness and stress.
The report refers to the term "nintenditis", coined by doctors to describe the injuries caused by overuse of video games.
Teachers are advised: "You should ensure that no pupil is allowed to work continuously with DSE (display screen equipment) without a break of at least 10 minutes every hour. With young pupils, breaks in work should be more often and could be shorter.
"Breaks allow those muscles and tendons that were in constant use to relax.
During these breaks, children should be allowed to stand up, walk about and use a range of different muscles."
The guidance adds: "Break time should not be used for personal use such as surfing the net, emailing or mobile phone texting."
It continues: "Although the prime duty of care rests with the employers and school management, considerable duties of care have to be delegated to teachers. Specifically, because of the ergonomic nature of the risks, teachers have to be responsible for carrying out a risk assessment on each child at each workstation.
"One way for this to be practicable is through classroom teaching. We suggest that children are trained to adopt good posture and working practices. This will include how to adjust workstations to fit their frames (or body sizes), and set up, adjust and operate equipment.
"Children will also need to know to take frequent breaks, to limit the frequency of working and to take regular, and fairly vigorous, physical exercise.
"If these health and safety arrangements are to be effective, then they are dependent on teachers training and supervising children in a continual interplay so that, by influence, children assume responsibility for their own personal welfare."
Sitting incorrectly at a computer, if done occasionally, is unlikely to cause harm, but doing so repeatedly puts the user at a significant risk of injury.
The guidance states: "The number of occasions children use computers and other forms of DSE such as games machines should be watched and may need to be limited. Some pupils use DSE in successive classes. Many spend more total time than this by working with DSE at home, possibly with most unsuitable furniture."
Do's and don'ts
The "precautionary approach"
* Table and chair heights should be adjustable.
* Children must be trained in how to adjust a chair and set it up properly.
"Hot-desking" means teachers and school management have to rely on the children to understand what should be done and how to do it, and to do it automatically at every workstation they use.
* Chairs should not have armrests except, arguably, in primary schools, where they can prevent very young children falling off.
* Where possible, a reduction in the use of the mouse should be encouraged and undersized mice should be provided for children with small hands.
* If the type of mouse selected is awkward for left-handers, provide a left-handed version.
* Laptops present a significantly greater risk than desktops because young users tend to use them lying prone, sitting on the floor, sitting with them on their lap, and sitting on a stool.