Early 70's, toboganning (sp?) down a icy/packed hill with a "jump" formed over a large rock (My butthole is puckering as I'm typing this!!!!)...
I hop on one of those plastic sheets of "blue suicide fun" and start down the hill (Mach 4.65)...
Hit the "jump"...
Shattered the "jump"
Tailbone hits rock that was the basis for "jump" ...
Stars and numbness are all I see and feel...
I've lost control of my lower half of the body...any gas in my intestines is rushing through an orifice that has no control...I sound like a wet woopy-cushion at a formal dinner...my face is buried in two inches of ice/snow and I can't move...I'm now recovering enough feeling and sense that I realize that there's a 129% chance that I'm permanently paralyzed...
Then the pain...no blood...just UNBELIEVABLE, INDESCRIBABLE, DON'T TELL ANYONE OVER 30, FREAKING
P A I N ! 
No one is helping me because I'm still emitting gas that should have stopped 30 seconds before...
Evenually, one of the guys realizes that my face should have emerged from the snow, so he figured that there's a bit more to my "theatrics" than they thought...
I ended up spending the rest of the weekend (This happened about 0900 on a Saturday morning...) "propped" near a fireplace, on top of three sleeping-bags - I wasn't able to walk for about 2 hours after the hit, then after the "bruise" and swelling settled down, I could hobble around like Festus on Gun Smoke...although, my disposition wasn't nearly as warm as his...
Haven't been on a sled since...
THE GROIN HIT
Early 80s - I'm working "Crowd Control" (CC) at the "Barn" in West Allis during the State Fair...4-H's are bringing their prize animals (cows, sheep, horses, etc....) into the center ring for judging and such...
One soul is using some sort of "scratching" stick (they scratch the belly of the animal for some reason?) and just when he's walking behind the cow -
P O W ! This kid is caught right on the Johnson and company and is launched approx. 12 feet into the center-ring's wall. He's "OUT" before he's down...
I hop over the fence from the audience area and get to him just as another of my fellow CCers reaches him. We pop open the pants and he's got a full hoof tatto on his groin/penis...I reach up into the audience area and ask for a kid's snow-cone...he gives it up without a word...I drop the cone on the kid's groin and we bundle him up to keep him from going into shock...the ambulance crew arrives about 45 seconds after the cone is in place...they pop him in the back of the ambulance and he's outa' there...
Later, his "area-leader" tracks us down to let us know that he's doing much better...he ended up with a severly bruised bladder and penis, he has some torn muscle/tissue in the area, but the main thing was that the bladder wasn't ruptured. We didn't ask what happened to his cow...
I don't know what could be worse - Rock or Hoof?
I hope that anyone I know will never find out...