I have to ATV's I have only crashed once.
I hit a stump and the 4-wheeler flew up I ended up flying off and slid across the rocks. Luckily the ATV didn't fall all the way back or I would have got hurt. Plus, my helmet also come off when I hit the ground and I hit my head really good. My back had a large vein-looking design on my back. Then I had to ride home which was a mile away.

Over all ATV's are awesome! Going to an ATV park and ridding for hours on end, feeling like you are lost, is awesome.