"A trampoline puts a child at risk for serious injuries," Cappello said. "Kids sustain broken arms, legs and even break their necks which can lead to paralysis. Just as you would not let your child jump into a shallow swimming pool, you should not let them jump on a trampoline."
Cappello agrees with a policy statement from the American Academy of Pediatrics (AAP) that says safety measures such as enclosure nets and padding have not substantially reduced the risk. "Therefore, the home use of trampolines is strongly discouraged," the Academy statement said.
The Pediatric Orthopaedic Society of North America said trampolines and moon bouncers are among the four main areas of preventable injuries in children. (The other areas are skateboards, ATVs and lawnmowers.)
Cappello said injuries typically occur when trampoline users land awkwardly. Common injuries include a broken ankle or a fracture of the tibia (shinbone) just below the knee. Users also can break their necks and become paralyzed. [emphasis mine]