Senior doctors are concerned by an increase in the number of children suffering serious injuries on trampolines, prompting new research to examine how to prevent hospitalisations.

There is an increasing number of children being admitted to hospital with serious injuries suffered on trampolines, including broken bones, head injuries and severe abdominal trauma, according to trauma specialists at Melbourne's Royal Children's Hospital.

They are so concerned by the incidence they have started a research project in conjunction with Melbourne University to study the injuries to help form injury prevention advice.

Melbourne's Royal Children's Hospital trauma director Dr Warwick Teague said the project would examine cases from home trampolines as well as trampoline play centres to see if they are contributing to the increase in severe trampoline injuries.

"We are seeing injuries that no family or child should ever be subjected to," he said.

"Our concern is high and that's why I feel there is a story to tell, otherwise we wouldn't be investing time and resources into the research project."

Dr Teague said the anecdotal evidence suggested many children were being injured when multiple were jumping on a trampoline at the same time.

"If you have multiple users on the trampoline, I would liken it to cage fighting," he said.

The study is due to be completed next year.

Doctors record increase in injuries

A decade ago, the hospital would admit about 30 children a year with serious trampoline injuries.

Last year that figure jumped to about 85 trampoline-related admissions, and Dr Teague said this year the hospital was on track to receive about 90.

Trampoline safety tips One child at a time

One child at a time Supervise at all times

Supervise at all times Always use safety padding on the frame

Always use safety padding on the frame Check the condition — particularly for holes in the net and mat

Check the condition — particularly for holes in the net and mat Make sure the surrounding area is free of hazards Source: Product Safety Australia

"We would estimate that a child who comes to the hospital with an injury is 75 per cent more likely to have been injured by a trampoline than they were in 2002," he said.

"The crude data suggests the highest proportion of injuries remain long bone fractures, so breaking either your arm or your leg.

"But there are also a very important number of head injuries and our anecdotal evidence is that more injuries are being sustained through collision than they were previously."

The hospital categorises "severe" injuries as requiring either an immediate response from the trauma team, an admission to the intensive care unit or treatment by multiple teams of specialists.

Dr Teague said over the past decade, he would normally see three to four severe injuries related to trampoline accidents.

"Last year we saw eight and we are on track for a further increase this year," he said.

Earlier this year, Sydney's Children's Hospital at Randwick issued a warning about a significant rise in the number of children admitted with preventable trampoline-related injuries following the opening of several indoor trampoline centres.

Safety net causing complacency, neurosurgeon says

Dr Alison Wray, a paediatric neurosurgeon at the Royal Children's Hospital, said it was possible some parents may feel more relaxed about a trampoline with a safety net and become complacent.

Dr Wray said the increasing popularity of that type of trampoline had given rise to different types of injuries.

Modern trampolines have a safety net to stop children bouncing off but can be dangerous if left unzipped. ( Flickr: SamuelSchultzerBagge )

"We now no longer see as much of the injuries caused by children falling off trampolines, but it gives a sense of complacency about the safety," she said.

"What we see is multiple children all getting on to the trampoline together, and the injuries we see are from children's collisions because there's more than one child on the trampoline at the same time.

"So it's not uncommon for them to knock heads together, we also see elbows versus head — which can be quite a nasty injury — also knees versus head, all sorts of combinations that can occur when people collide."

Dr Wray also treats children injured after tumbling out of trampolines where the safety net is unzipped, or unsecured trampolines picked up by the wind.

"Just because there are safety nets around it, doesn't mean that the situation is as safe as it could be," she said.

A parent's warning: 'Always remember to zip up your trampoline'

In late August, six-year-old Melbourne boy Edgar became one of the Royal Children's Hospital's latest patients after he fell out of a trampoline with an unzipped safety net.

His mother, Kim, said he toppled out headfirst onto bluestone bricks with nothing to break his fall.

"I heard a wail that went straight to my marrow and I knew there had been an accident," she said.

After watching her son for several hours, she put him to bed.

"I thought we were out of the woods but he vomited shortly afterwards and started vomiting quite intensively two hours later," she said.

Edgar was taken to the Royal Children's Hospital, where Kim said the doctors were concerned Edgar had fractured his skull and might have internal bleeding as he described the head injury as feeling "boggy".

A CAT scan came back clear but revealed Edgar had suffered a brain trauma.

"This was not caused by the head hitting the pavement but by the brain hitting the skull," Kim said.

Edgar is now being monitored by the Concussion Clinic at the Murdoch Children's Research Institute that is examining the long-term repercussions of concussion in children.

Three weeks later, the six-year-old remains a little uncoordinated, occasionally muddled in his thinking and has not passed several balance tests.

But he is back at school and Kim said she felt "incredibly fortunate that this stupid accident, entirely a result of our parental negligence, didn't result in anything worse".

She said Edgar's gym teacher told her there are two lessons in life: always remember to zip up your pants and always remember to zip up your trampoline.

"It's a wonderful creed and one I would urge other parents to follow," she said.

"It's only after this sort of thing happens that one hears everyone else's horror stories and as we have had up to five children on our trampoline, a risk we would never have considered on the old sprung type I grew up on in the 1970s."

One of Kim's friends had her son lose an adult tooth and her daughter forced into plastic surgery after they collided.

"I think we assume they're safe and cram more kids on. I've been to parties where there have been 15 kids on them," she said.

"I am surprised we didn't end up at the Royal Children's Hospital with a head injury earlier."

Trauma surgeon recommends one child policy

Trauma director Dr Warwick Teague said trampolines can be safe if they are used appropriately.

"Many times, I am in a social scenario where I am the slightly awkwardly over-protective parent who takes my own children off the trampoline because there are multiple children on," he said.

"I see them bouncing backwards and forwards and they bang into each other constantly, they rumble and they tumble and kids do fight for fun and sometimes it seems to me like a cage fight.

"I could not truthfully say that my children have not all been on the trampoline at once, but their father does not approve of that and if they are found to be all on the trampoline there are significant family-imposed repercussions."