Christchurch emergency doctors have seen 28 injuries in just two months from indoor trampoline parks in the city, including two people who broke their necks.
A teenage boy suffered serious spinal injuries at Mega Air Trampoline Arena last week.
The centre is defending its "rigorous safety precautions".
Canterbury District Health Board (CDHB) will not reveal details of the boy's condition as the family had requested "complete privacy".
The Mega Air and Flip Out centres have opened in the city since August.
CDHB's emergency department director Dr Scott Pearson says it has seen a cluster of injuries linked to the centres, including two broken necks, fractures, lacerations and serious spinal and facial injuries.
Pearson said 10 people were injured in August and 18 in September from accidents at the parks.
"We have seen a cluster of trampoline-related injuries in recent months, linked to the two new indoor trampoline parks in the city," he said.
Worksafe said it was notified of a person suffering a "spinal injury" at Mega Air last Monday.
Worksafe staff were making preliminary enquiries before deciding whether to investigate further. No prohibition notices have been issued, a spokesman said.
It also said it was carrying out enquiries to determine whether they'll investigate trampoline-related injuries in Christchurch.
St John Ambulance spokesman Ian Henderson confirmed it was called to Mega Air in Hornby just after 6pm last Monday.
A boy in his mid-teens was taken by ambulance to Christchurch Hospital with serious injuries, Henderson said.
It was not known how the boy was injured.
In a statement, Mega Air Trampoline Arena director Matthew Haselden said the operation has robust health and safety measures.
"Every customer is required to follow rigorous safety precautions and take part in a safety induction, which includes viewing a health and safety video.
"There are also between 5 and 11 jump guards plus a duty manager supervising the facility at all times." "Real-time video footage allows staff to watch, review and assess safety at all times."
Haselden said Mega Air was the country's biggest trampoline centre. It opened on August 16 and more than 31,000 people had visited the centre since.
"We are very upset that this injury has occurred and we have been in regular contact with the boy's father to offer support," Haselden said.
"What happened last week appears to have been a freak accident."
The company also contacted WorkSafe, which visited the site last week and advised Mega Air that the foam pit, where the injury happened, met health and safety requirements and could re-open.
"However, as per plans set out three months ago, the foam pit will be replaced with an air bag this week, which is why the foam pit is currently closed."
Nearly $1 million was spent ensuring the facility was safe for public use, Haselden said, and more than $500,000 was spent putting specific health and safety measures in place.
Before the centre opened, Consulting Engineers from NZ carried out a full compliance test, Haselden said.
A senior New Zealand trampolining coach and 44-year veteran of the sport, Nigel Humphreys said he would raise his concerns with Mega Air today.
"First and foremost of my concerns would be the level of training of the staff, but also the facility itself - there needs to be considerable thought with regards to how it's laid out," the owner of ICE Trampoline Sports in Rangiora said.
"My athletes have bought a session within both of the trampoline parks, but bear in mind they are athletes with a considerable amount of skill on a trampoline."
Humphreys said an ordinary person using a tramp might not have the same level of tension in their body as a professional athlete.
The bounce from the trampoline would rebound on the person, and if they aren't properly set, accidents could happen.
A post on Mega Air's Facebook page the day after the accident stated that the foam pits had been closed "in preparation for the arrival of a brand new air bag!".
As well as the extensive trampoline areas, the park also has at least two sponge pits.
The main pit is described on Mega Air's website.
"Five trampoline launch pads allow you to catapult into a 9m sponge pit filled with thousands of gymnastic-grade foam cubes. You can practise your aerial moves before you have a soft landing in the sponge pit.
"For safety's sake, we do not allow diving or landing head first and only allow a single jumper at a time."