A former teacher has designed a school chair which he claims is impossible to tip backwards.
Mr Wates designed the chair as he was irritated by pupils leaning back
Tom Wates gave up his teaching post in Blackheath in south-east London to design the "Max Chair".
It has curved legs that prevent it rocking and provides more support for the lower back, forcing children to sit up straight.
His company has already received orders for 1,500 chairs from 18 schools having launched the product three weeks ago.
Mr Wates, 34, said it is physically impossible to swing the chair backwards more than a few centimetres.
"The reason I went into it was because of the irritation of children leaning back," said Mr Wates who gave up teaching in July 2007.
"You would get into the flow of the lesson, the kid would fall off the chair, everyone would laugh and you would have to start again," the former maths and PE teacher said.
About 7,000 British school children need to go to hospital each year after injuring themselves by tipping backwards on chairs, according to government figures.