It’s dangerous and it drives teachers to despair. But now the problem of pupils rocking on the rear legs of their chair has been solved: a former teacher has developed an untippable one.

Tom Wates has taken orders from 18 schools since launching his product three weeks ago. “I’ve had orders from Glasgow to Belfast, Cornwall to London,” he said. “It seems that it’s a problem that touches everyone.”

Mr Wates, who gave up his job teaching maths and PE in Blackheath, southeast London, last year, said that he was “driven mad” by his students rocking back and forth, and often falling off their chairs. “It was something I was saying as much as I was asking children to be quiet. I couldn’t do anything about them talking, but I figured that I could stop this.”

Of the 7,000 pupils admitted to hospital a year as a result of chair-related accidents, 70 per cent resulted from rocking back dangerously, according to government statistics.

The Max chair, created by the design company Sedley Place, has curved legs that prevent rocking. Mr Wates said that no child could lift it more than 5cm off the ground. “For me, this started out as a way of combating the irritation of the children rocking. But at nearly every school I’ve been to teachers relate a story about an injury. It is a danger issue.”

Teachers welcomed the idea and said that chair-rocking was one of the biggest distractions in the classroom. A teacher in North London who did not want to be named said that she dealt with the problem by forcing misbehaving children to kneel on the floor. “They are in your care and it would only take a hypersensitive parent to put the blame on you if their child hurt themselves,” she said. Another teacher, whose charges are aged seven and eight, said that tipping was a constant interruption and that three or four children fell off their chairs each day. “They always look surprised when it happens,” she said. “The problem is that other kids start laughing and then I’ve lost 10 minutes of teaching time.”

In a discussion on the Times Educational Supplement website, teachers complained about the amount of time spent trying to stop students rocking.

Not all were keen on the Max chair. One wrote: “Much cheaper to make them sit on the floor!”

Julia Neal, president of the Association for Teachers and Lecturers, said that schools should consider the chairs for health--and-safety reasons.

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