I was reading through this thread again, and I started to think about something else.
If you break you neck on a fall the "best" break is if the neck is broken in the back, and the worst if broken inside. I think it had something to do with the area swolling (sp?). If it swols in the back, not that bad, if it swols inside your neck you sufficate.
In this sense I would say the worst fall would be breaking your neck on a front fall.