Canadian researchers say they have found a way to reduce the risk of severe fractures known as “trampoline ankle,” while taking note of other serious injuries to adults and children including broken necks, spinal cord injuries and disabling head traumas.

The doctors reviewed 11 cases of trampoline-induced fractures and found that more one person had been jumping on the trampoline, in nine of the 11 cases.

Even though the trampoline surface looks pliable and rubbery, the surface can become as hard as cement with the force of jumping.

Dr. Luke Gauthier, an orthopedic surgeon Dalhousie University was one of the authors on the study. He explained that trampoline mats become as hard as a solid surface when two or more people are jumping out of sync.

The force when hitting the mat can become, “equivalent to falling from a building,” said Dr. Gauthier. This can cause permanent bone damage.

Glace Bay teenager Logan Dean wants that message to spread. He injured his ankle while goofing around with friends on a backyard trampoline at the age of 12. The injury was so bad that it took three surgeries over seven years to fix.

“I think it is important that people know what can happen if you don't properly use a trampoline,” Dean said. “It can be very dangerous.”

“Our word of warning,” says Dr. Ron El-Hawary, “is one child on the trampoline at the same time.”

With a report from CTV National News Medical Correspondent Avis Favaro and producer Elizabeth St. Philip