I've now seen two weekends in a row where cyclist have crashed and *not* used their hands to break their fall. The conventional wisdom is that if you stick your hands out to stop your fall you'll break an arm/hand/wrist badly.

But I don't get it, in one of these crashes the cyclist whacked his head on concrete pretty hard. Sure he was wearing a helmut but one can still get a head injury can't they?

Does anyone practice this idea of not breaking your fall with your hands?