The Three Collision Rule

I imagine it was probably my first Prehospital Trauma Life Support class back in 1990 that I first heard of the three collision rule. Since then, it has remained a useful tool in examining the mechanism of injury after auto accidents. If you haven’t heard of it, please allow me to elaborate. The three collision rule states that, in any auto accident, there are three collisions that occur and the keen EMT needs to be aware of all three. The next time you walk up to a vehicle accident, instead of imagining two large objects colliding with each other, imagine three separate collisions occurring with each respective vehicle. All of them have implications for the alert EMT. Contents Collision Number One: The Exterior of The Vehicle Strikes SomethingCollision Number Two: Stuff Within The Vehicle Moves Toward The Point of ImpactCollision Number Three: Stuff Within The Patient’s Body Strikes The Inside of The Patient’s BodyCollision Number One: The Exterior of The Vehicle Strikes Something Take a quick walk around the vehicle and consider the elements of Newton’s second law (force is mass times acceleration or deceleration). Ask yourself the questions that apply to that equation. How heavy is the vehicle involved? How fast was it traveling? How fast did it stop? All of these will contribute to the force involved in the initial impact, but speed really is king. Force increases proportionally as the weight of the vehicle increases, but speed has an expon...
Source: The EMT Spot - Category: Emergency Medicine Authors: Tags: EMT Source Type: blogs