Ah, yes, schoolyard/gym class fun. with all the attendent scuffed up knees, etc.
Actually, best gym class I had was in high school (A Catholic private school no less)....They got these "indoor" hockey setups, with plastic sticks (but about 3/4 size) and a plastic puck. Puck wasn't heavy enough to do any real damage, even the sticks wouldn't do much more than sting you good. But, we were out there body checking and slamming each other around, like no tomorrow, with NO protective equipment. MUCH better than dodgeball. I'm sure parents today would have a cow if kids of any age were allowed this in gym class.
Then after school there were the "sandlot games"...football, yeah every year we (the neighborhood kids, about 25 ina 5 year age span) played football (at least 3 broken bones every year), baseball (fewer broken bones, but still plenty of injuries), "boot hockey" (few could skate) ALWAYS good for some serious injuries--game usually stopped when there weren't enough "healthy" players left. And in between all that we'd be jumping bikes off ramps, etc. Usually, some more broken bones there each year.
And, our parents thought nothing of any of this, they just trucked us off to the hospital/doctor to get patched up. (By the time I was in my late teens I had acquired more than 200 stitches...but only 1 broken bone). It was part of being a kid!