Calls for better regulation of trampoline parks have been made nationally despite ambulance call outs in Norfolk going down.
The number of parks has jumped in recent years. Before 2015 Norfolk did not have any, but now has Gravity and High Altitude in Norwich, and Jump Warehouse in Great Yarmouth.
Nationally there are more than 200, up from just three in 2014. And there were 1,200 ambulance call outs last year compared to 760 in 2016.
But there are no mandatory safety standards set up for parks, instead a voluntary code was set by the International Association of Trampoline Parks (IATP) last year.
When High Altitude, in Whiffler Road, was the only Norfolk park in 2015 ambulances were called there 11 times - five of those calls were for traumatic injuries.
And this soared to 21 call outs in 2016 (12 traumatic injuries), a Freedom of Information request made by the BBC revealed.
But last year the park committed to being fully compliant with IATP standards and in 2017 paramedics were only called twice.
Fran Habbits, director, said she was proud of the park's progress. She said : 'Looking at our statistics in the last 12 months we've had no major incidents. I reckon we've had in excess of 55,000 people bouncing without major incident and minor incidents over the last few years.'
Gravity, based on Norwich's Riverside, recorded 12 ambulance call outs in 2016 - the year in which it opened - five of which were for children.
But this dropped to seven last year, five of which were for children.
Mark Harrison, owner of Gravity Trampoline Parks, told the BBC the sector 'must be governed'. He said: 'Some of these parks should not be allowed to operate and my worry is that some of these parks are injuring people through financial and commercial reasons.'
Jump Warehouse, in Main Cross Road, Great Yarmouth, has had no ambulance call outs since it opened in February 2016.
Director John Wilson said this was down to being strict with safety rules and education.
He said rather than take an approach similar to that of a lifeguard, his staff would speak to customers doing things wrong and explain to them why it was not safe.
He said: 'Our lads will go out on the court and talk to the children about what they're doing wrong.'
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