Some horses you will need to ride out but if you don't have to why would you put yourself at that risk? There are so many things that can be taught on the ground that you don't need to get on and teach them. I don't like getting on and going to battle. I'd rather take a bit more time and do it right then foolishly get on and get hurt.
I am lucky though. No broken bones in my adventures. I started riding with knee pads though because I got slammed into a wall, skinned my knee but my breeches were still intact, and continued to ride. My knee fused to my pants and I had to go into the bathroom after and rip it off. Yeeeouch.