Trampolines can provide hours of fun, but they can also lead to serious life-altering injuries. In 1999, the American Academy of Pediatrics (AAP) required manufacturers to add safety features like surrounding safety nets to mitigate risk. But now, after assessing years of findings, the AAP says the features provide a false sense of security, and the group is urging pediatricians to discourage parents from setting up trampolines at their homes. Though the estimated number of trampoline injuries nationwide has been decreasing, the recreational devices are still considered dangerous. Here, a look at the numbers behind this risky contraption:

Trampoline-related injuries treated in the ER in 2004

Trampoline-related injuries treated in 2009

Those who were required to remain in the hospital in 2009

Children in the U.S. hospitalized every year as a result of bicycle crashes

Children in the U.S. injured every year because of skateboarding 

Percentage of the approximately 900,000 consumer trampolines sold each year that include a safety net

Percentage of trampoline-related injuries resulting from multiple people jumping on the mat at the same time

Percentage of injuries in the 5-and-under age range that result in fractures or dislocations

27 to 39
Percentage of all injuries caused by falls. These can be "potentially catastrophic," says the AAP

Percentage of injuries caused by direct contact with the springs or frame

Percentage of injuries that damaged the lower extremities, including ankle sprains

10 to 17
Percentage of injuries to the head and neck, which are less common but can cause "permanent neurological damage"

Sources: American Academy of Pediatrics, BabbleMy Health News DailyRacing for Safety [PDF]