Well, one time, long long ago, when I was seven or eight, my friend and I were playing soldiers on the beach. We dug a pit each, a few feet down, then run and lept into the air landing in the pit knees first. (Not very wise jumping like that, as we could have been easily picked off by enemy sniper fire).
Anyway, my pit digging skills came under scrutiny, after I landed knees first on top of a smooth large boulder in the sand.
So, concerned at my excruciating pain and soccer premier league style rolling around in the sand, my friends parents decided it was best to take me to ER.
This was were the story ended, the hospital said I was ok.
(a bit of a lame ending to the story).
Ps. I've never been to the ER