First off, while not actually dealing with the subject at hand per se, the following study did come to the surprising conclusion that Log-Rolling Pt's produced far more potentially injurious C-spine motion then the "Lift-and-Slide" technique. Anybody else surprised?
The Spine Journal
Volume 4, Issue 6, November-December 2004, Pages 619-62
C-Spine.pdf
In regards to your post Kiwi, this is from an older post of mine. It does not take much force to cause a c-spine fracture. Dust was right on the money when he said: "the unfortunate fact is that there is no recognised, objective criteria available in an unconscious patient with which to rule out spinal injury. "