Last time we talked about the most important factor as to whether or not you will be injured in a car accident. People who know they are about to crash seem to do much better than those who don’t. This Denver Chiropractor wants to give you more information about car accidents.
Getting rear ended at 5 mph in Denver doesn’t seem like a large amount of speed but when you back that up with the size or mass of the other vehicle hitting you , well that can add up to a significant amount of force. The bigger the vehicle, the more difficult it is to stop. This is called Inertia. Here’s the equation: Force= Mass x Acceleration. The more Mass, the more Force. It CAN cause neck pain.
What’s also interesting is that you can not judge the severity of patient injuries by the severity of the damage to the vehicle. Most cars these days are built to withstand impacts of up to 12 mph with no apparent damage. When a vehicle gets crushed from impact, some of this Force is absorbed by the vehicle’s construction materials during the crushing process and less is transferred to the driver and passenger.
However, when there is little to no crush of the vehicle, the full force of the impact is absorbed by the occupants of the car, potentially resulting in more injury.
A rear impact of a vehicle sitting at at traffic light, suddenly accelerated forward 5 mph, causes the vehicle to sustain a G force of 1.9. (Trust me, I worked out all the math). This is almost 2x the amount of force we normally experience due to earth’s gravity.
The real factor though is that the people inside the car are subjected to even higher G forces. It has been shown on live human test subjects that these forces are actually 2-3 times greater than that sustained by the vehicle. That can mean G forces of anywhere from 6-12! And here’s the real significance of all this. Ligaments and discs have been shown to suffer injury at G forces of only 3.5. That’s how getting rear ended at 5 mph in Denver can cause neck pain!
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Next time we’ll talk more about risk factors that can cause neck pain from getting rear ended at 5 mph in Denver.
1. Spine (Phila Pa 1976). 2004 Jun 1;29(11):1217-25.
Injury Mechanisms of the cervical intervertebral disc during simulated whiplash
Source: Biomechanics Research Laboratory, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT 06520-8071, USA. firstname.lastname@example.org
2. 1958 Severy et al. Automobile barrier and rear-end collision performance. Presented at the Society of Automobile Engineers summer meeting, Atlantic City, NJ, June 8-13.
(Severy’s group were the first to show that the acceleration of the human head in low speed rear impact collisions could be up to 2-3 times or more higher than the occupant’s vehicle. This is due to the unique and complex occupant-vehicle coupling of this type of crash.)