TORONTO -- Just as kids love to bounce on beds, they are also drawn to the joy of jumping on trampolines -- a pastime that has likely become more popular since Canadian Rosie MacLennan clinched gold in the Olympic version of the sport.
But doctors warn that backyard and other recreational trampolines pose a significant risk of injury, especially to younger children.
In an updated policy statement issued Monday, the American Academy of Pediatrics (AAP) "strongly discourages" the use of recreational trampolines, either at home or in commercial indoor parks that feature the high-flying gymnastics equipment.
In January, the Canadian Paediatric Society reaffirmed a similar position statement last issued in 2007.
"The key thing is that three-quarters of injuries occur when there are multiple users on the mat," said Dr. Michele LaBotz, co-author of the AAP statement.
"And you see that all the time: adults like to be on the trampoline, bouncing with the kids," LaBotz said from Portland, Me., where she practises pediatric sports medicine. "And especially when you get those disparate sizes -- you get a real big person and a real small person -- the small person is much more likely to get injured, 14 times more likely to get injured.
"And the injury sustained by a smaller person is much more likely to be severe. So in children less than the age of five, for instance, their rate of fractures and dislocations is 48 per cent."
Injuries can range from broken wrists, dislocated shoulders and sprained ankles to severe head and neck trauma. About one in 200 trampoline injuries leads to permanent neurological damage, a U.S. study in 2000 found.
One injury unique to trampoline use is a form of broken leg called a proximal tibia fracture that is primarily seen in children under age six, she said.
"Most of them have occurred on the trampoline with older folks. One principle a lot of us kind of overlook when we think about the trampoline is that most injuries actually occur on the centre mat itself.
"If you get an adult who's about 170 pounds bouncing with a kid who's 40 to 50 pounds, the recoil of the mat, when that kid lands -- and especially if he's not landing right -- he generates about the same amount of force as if he went from nine feet (three metres) onto a hard surface.
"And you don't think of that because the mat's kind of soft and bouncy," LaBotz said.
That means that netting around a trampoline, aimed at stopping a jumper from falling off the equipment, or protective coverings on the surrounding springs, will not prevent about two-thirds of injuries, which occur on the central mat.
Head and neck injuries most often result from a failed flip or airborne somersault on the trampoline, she said.
"So that's why we have such a strong recommendation against that particular stunt."
Almost 98,000 trampoline-related injuries are estimated to have occurred in the U.S. in 2009, the latest year for which statistics are available, down from a high of more the than 109,500 in 2006.
In Canada, 4,247 cases of trampoline injuries were reported over the five most recent years of data. That figure does not represent all such injuries in Canada, but only those treated in the emergency departments of 15 hospitals in the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP).
More than 40 per cent of injuries involved children aged five to nine, and more than eight per cent of all those injured had to be hospitalized. Between 2005-06 and 2009-10, the rate of trampoline injuries almost doubled in Canada, CHIRPP found.
Lower limbs were the most frequently injured (43 per cent), followed by the upper extremities (36 per cent) and the head, face and neck (15 per cent). Overall, fractures accounted for 43.5 per cent of all injuries, while about three per cent involved brain trauma.
-- The Canadian Press