[bigjames]

Methinks the good Doctor is on to something. If the intent of a helmet is to absorb shock and decrease the chance of snapping ones neck and/or tweaking the brain inside the skull (torsional force and close head injuries), it makes perfect sense to build some movement into the outer shell, or make the outer shell out of a softish energy asboring material that is also pucture resistent. He is not the first one to try this. Years ago I met a guy named Uwe (pronounced you-ee) from Germany who had a helmet that kinda looked like a golf ball but had a relatively soft outer shell (that would emulate a hard shell being able to move somewhat). In his opinion, it saved his life when he went under a guard rail in a high speed crash. Instead of the helmet stopping him from going under it, part of the outer shell sheered off (if hard and moveable, it would presumably move out of the way)! It was still able to absorb the shock of whatever eventually stopped him. However, what ever the Doc comes up with will probably never be sold here because of antiquated DOT requirements and our lovely product liablilty laws or lack of common sense there of!