Funny story: I was out in the field recently and was walking up a rather steep, unstable surface. There was a rock wall I was walking next to, so I reached my hand out to stabilize myself using it. Well, about halfway up I lost my footing and fell. When I fell my hand stayed where it was, the arm bent 90* at the elbow, and stayed in place as I fell forward. A very effective kimura by the wall versus me. After I recovered from my shoulder popping out of joint and then back in, I had to laugh at it. Of course now, my shoulder is all jacked up, and I have to be careful what I do, but it seems to be healing up pretty fast.