It's safe; just ask the kid with the cast
It was a humorous moment. But to parents the situation is far from funny.
According to a CBS News story this year, in 2009 there were 98,000 trampoline injuries so severe that they required Emergency Room treatment. Eighty-two percent of those injuries were to children under the age of 15.
Manufacturers have made some efforts to keep children from falling off the devices and from coming in violent contact with the hard metal frames. We've all seen the padding and the nets that have been added to trampolines. Strangely, manufacturers often sell the things without these safety features. Even when trampolines are equipped with these safety measures, the pads and nets can easily be removed.
It is also important to note that many injuries result from attempts to do "tricks" on the trampolines. Children can break spinal bones from unsuccessful attempts at somersaults and flips. According to one Canadian study, 10 percent of those injuries result in paralysis.
Statistically, giving your children a loaded handgun to play with is only slightly riskier than giving them a trampoline.