In my personal injury cases, I often hear the insurance company's lawyer argue that the rear end or frontal collision was at low speed and didn't cause much damage to the car, so my client couldn't have been injured. Is that correct? Not at all. Severe injury can occur even at low speeds, when vehicle damage is minor. I've seen bad injuries happen from parking lot speed collisions.
Lawyers handling these cases have to understand anatomy and physics. Impact speed and change of velocity of a struck vehicle aren't good gauges of whether a person was hurt, despite insurance company arguments to the contrary. Despite years of testing with dummies and with real people in crash tests, researchers have been unable to establish a threshold speed for injury. For example, some have spines that are weaker from prior injury or age. Also, angle of collision, how the person was positioned in the vehicle at the moment of impact, and countless other variables factor into injury.
Research has established that injuries can occur at speeds of between 1 and 2.5 miles per hour. Why? How the vertebrae in a neck or low back move in relation to each other is far more important than speed of impact or damage to a car in determining damage to a person. Peak acceleration in one direction in the lower neck may occur at a hundred milliseconds into the collision, but in the upper neck it might occur at eighty milliseconds. That means that shear forces are generated, and that can spell big trouble for a person's spine.
Testing has indicated that in a rear impact, 13 different forces are exerted at the base of the skull. Similar forces at every other part of the spine, as would be expected, indicate that a person hit from behind would be subjected to hundreds of forces applied in less than a half second. Now you know why low speed impacts can be very damaging. Be careful on the road.