My 7 year old has just broken his finger on one.We have a trampoline and he is an only child. Had it 3 years, he's never been injured on it. When his friends come to play we only allow one child on at a time, boring I know, but we are very hot on safety.He went to his friends house who have 2 boys one is a big lad of 12 the other same size as my son. My friend let all three on together, other boys are very, very rough when they play.I wasn't there otherwise wouldn't have allowed it. My son was bounced up in the air by the heavy boy and came down full weight on his finger which bent back to touch his palm.You can imajine the pain he was in.He had it manipulated under General Anesthetic and so far all seems ok.This accident could have been avoided, yes we know it could have happened on our trampoline but a survey I found shows more accidents happen when there are 3 jumpers at the same time. So be careful if you allow multiple bouncers.He is glad about the fact he will have to have a scribe for his SATS, he hates writing.