<qa>  What is the Canadian C-Spine Rule?This research group recently developed and tested a highly accurate and reliable guideline called the Canadian C-Spine Rule to help physicians be much more selective in their use of neck x-rays and to minimize the period of immobilization. This research project will evaluate the true effectiveness of the Rule when implemented with simple and inexpensive measures. This study will involve 14,000 patients in 12 busy emergency departments across Canada. 