Take one large 15-year-old, squash him untidily into the chair just vacated by a tiny 11-year-old, point him at a computer screen, offer a well-worn keyboard and an exciting program. The chances are - especially if it's 22xC outside and he's at a desk by a window in a room with 24 other Year 10 kids - that he will be physically jaded by the end of a lesson. And he will have back cramps or grumbling hands.
The same 15-year-old, on work experience, will discover that, like many offices, his classroom would breach European Commission directives. These say that the workplace must be designed to prevent the muscular-skeletal injuries computers can cause, collectively known as repetitive strain injury (RSI).
The drive to make the magic of technology available to all students has not been matched by a compulsion to look at the possibility that pupils might learn bad habits or even be injured by computers. For the first time, we are faced with the prospect of children as young as five spending a considerable number of hours each week in front of a screen. And no one knows what the cumulative damage of bad posture or will be.
The issue is serious enough for adults. According to the TUC, one in fifty workers using computers suffers pain and one in a hundred will need time off. But no significant research has looked at effects on children even though intensive computer use could pose them particular dangers. Julia Fraser, a physiotherapist with experience of adult and child RSI problems, says teenagers are at risk of injury because they are growing fast, and their bones and joints are easily damaged. Although in some respects children heal faster than adults, Ms Fraser says skeletal and joint ligament problems need to be treated with care. In short, any injury must be treated effectively and quickly to avoid permanent deformity.
There are workplace directives that dictate light and air quality, standards for desks and chairs, and that insist on rest breaks and training. But these protect only employees, which in schools covers teachers and office staff. There is no directive to oblige governing bodies, heads or teachers to seek expensive ergonomic advice for pupils. This is undoubtedly one reason why most schools have not taken on board the need for preventive education.
The second factor must be the lack of recorded cases of RSI in children. Dr Edward Husskisson, a leading RSI consultant in London, said he had never treated a child with RSI, but knew of some. "It can happen. And many musculor-skeletal problems can be prevented. Preventative therapy makes sense when you have seen RSI patients."
Owen Tudor, the TUC's health and safety officer, believes there is a need to quantify potential problems and offer training in computer use. "There are 3.5 million schoolchildren and computer use is growing. It is difficult to work out the risk," he said.
"But how can you teach students to use equipment without training? You wouldn't teach someone to cut wood without telling them how to use a saw. Computers don't look dangerous, but they are."
The Body Action Campaign, a charity that uses theatre in education to teach posture and good practice, was launched last year with a claim from its founder, Bunny Martin, that up to a quarter of pupils might suffer RSI symptoms.
Ms Martin, a therapist offering preventive training, bases her claim on guesstimates of the number of adult sufferers. The symptoms she talks about range from mild discomfort to potentially crippling pain. She has treated young children with severe problems.
Often the causes are misuse of home computers and games machines, rather than the short periods of computer use in schools. But she says: "It is easier to reach children through the school and they need to understand what they are doing with their bodies."
Since this is the first generation to grow up with computers, she says, it is impossible to know the extent of possible damage, but the problems that adults suffer dictate caution.
A Swedish ergonomist, Ulf Berqvist of the Stockholm Institute for Working Life, is co-ordinating a survey of urban schools in North America, Japan and Europe to assess schools' ergonomic provision.
In Britain, Systems Concept, an ergonomics consultancy, will conduct the research. Tom Stewart, its director, says the problems schools face are complex because children come in a wider range of shapes and sizes than adults. It is more difficult and expensive to provide furniture that will adjust to them all.
Some schools do offer safety advice. Judy Jakes, head of IT at the School of St David and St Katharine, a north London comprehensive, is careful to buy good equipment and organise classrooms ergonomically. She talks to pupils about posture, keyboard use and rest breaks, and offers a health and safety unit, using materials gathered from manufacturers' advice sheets to Year 10 pupils preparing for work experience. "We don't have the timetable space to teach keyboard skills and health and safety more widely." Training children, she believes, is best given at primary school, when they are at an age to start exploring the technology.
None of the teachers' or education organisations have conducted research, nor are teachers being trained to offer health and safety advice. The NUT, the biggest teaching union, says teachers are not in the frontline because few work long hours at screens. It refers members to TUC guidance. The National Association of Head Teachers has had no significant expression of concern from members and, therefore, has not organised advice either on safety, or teaching good practice to pupils. But both unions recognise that this will become an issue for the future.
The care that manufacturers take to attach health warnings to computers is a measure of the care that schools need to take to ensure the next generation of workers avoids RSI.
SIGNS TO WATCH OUT FOR
1 Whole body discomfort after long period at computer
2 Arm or hand pain
3 Arm or hand heaviness or weakness
4 Pins and needles in the hands or wrists
5 Elbow discomfort
6 Back or neck numb spots - suggesting trapped nerves
7 Back or neck pain
1 Computer desk and chair should allow user to sit straight.
2 Get posture charts. Health and Safety booklet contains position guidance
3 Service equipment regularly
4 Take regular breaks
5 Walk around in the break. Roll shoulders and shake hands and wrists
6 Ensure light is good
7 Ensure air is clean and not too dry
Health and Safety Executive
Helpline 0541 545500
VDUs an Easy Guide to Regulations: HS(G)90; pound;5
The Trades Union Congress
Great Russell Street, London WC1
The Body Action Campaign
21 Nutwell Street, London SW17 9RS Write with sae