Summarize the following text:

Trampolines may be fun, but they can also be dangerous. Experts estimate that more than 100,000 people hurt themselves while using one each year. Clubs and gyms use large safety nets and rubber padding to make it safer. Most trampoline injuries happen at home. These injuries happen for many reasons. People may bounce too high and land off of the trampoline or onto the springs. From the peak of the bounce, this can be a fall of 13 feet or more. Ouch. Injuries also happen when many people are jumping at the same time. Jumpers may collide and cause one another to land in strange ways. Lots of people have broken bones in this way. Perhaps the worst injuries happen when untrained people try to do flips. Landing on your neck or head can paralyze or even kill you.