To take this to an extreme (and not even as a reducto ad absurdum): if a child does something that has the potential to break a bone... that thing should still be basically considered "safe." Children's bones heal!

Yes! My 8 year old son recently wanted to ride down a steep hill but he was afraid. I asked him what the worst was that could happen and he said that he would fall. "OK, and if you fall, you might break a bone?" "Yes" "So? You'll be fine."

He rode down that hill until it was time to go home and even fell a couple of times (though no bones broken). Mission accomplished.

Well... yes. Kids play sports and that often results in broken bones. And I mean even simple sports, not things like rugby, where you're actually aiming to physically stop someone else from moving.

physically I'd agree.

Emotionally, no way.

Yeah. But look at the bright side: Not every part of growing older sucks.