When I was in elementary school, we had a playground. It had no swings, no slides, no jungle gyms. It was paved in good old-fashioned asphalt and promised a properly scraped knee or worse to anyone who failed to keep upright while running over its surface. In fact, running and hopscotch were pretty much the only things you could do on this playground. Perhaps you could get a game of "tag" going (running) or dodge ball (running, getting hit by balls, falling down). When I think back on it, I am amazed we weren't all injured daily.
I have thought about it and decided it isn't really possible that today's children are more fragile than those of yesteryear. The only real difference is our level of concern for their safety, which now extends to trying to make sure they never fall down, never trip while running, never get a scrape or need all those bandages we fill medicine chests with. The reason is simple: it's the adults who have become more fragile. We can't stand the thought of seeing our children in even the slightest pain.
On some level I know my children will survive the usual bumps and thumps of childhood play, but I wonder at times if I will.