Speaking on MOI, I understand the spinal cord is one long piece, but it still doesn't make sense to me that someone who is shot in the chest needs a c-collar. I haven't been convinced that moving the head really moves the spinal cord in the chest/lumbar region much. The converse also goes for whiplash injuries. Those patients leave the hospital in a c-collar, walking. So I don't understand why someone who gets rear ended at 20 MPH, has neck pain but no back pain needs a board. Just collar them. I know that hasn't been proven with research but someone should get on it.
Your asking for some part of spinal immobilization to make sense. Good luck with that.