You ever know someone who fell, and broke a wrist, or elbow? It's probably because he/she put out her hand, and in landing on the hand either broke the wrist, or the force transfered up the forearm and broke the elbow. Point force is VERY bad for the body.
If you are going to fall, land on the broadest, largest part of your body. And if you can, try to roll.

A few months ago, a girl cut me off and I ended up ditching the bike and hitting gravel in a parking lot doing about 18mph. rather than sticking my hand out, i let my entire right forearm take the hit, then rolled onto the shoulder and caught the left hand and right leg as well. I had nasty road rash, but that's it. Why? because I let the MOST parts of my body absorb smaller amounts of force. In contrast, my girlfriend fell off the last step of her stairs at home and broke an elbow because she put her hand out.

Luckily in 8 years of karate training, one of the things we REALLY focused on was how to fall correctly. If you roll with the force you can survive it. The body doesn't take point impacts well, but it can handle blunter impact. Think of the difference between getting hit with a baseball bat, and getting hit with the broad side of a 2x4.
The bat will break bones. The 2x4 is likely to sting like hell, and give you a welt, but is less likely to cause true deep tissue damage. The force is more broadly distributed.

I dunno if I was clear. Did that make sense to anyone?