In the last two writings we explored how low speed collisions can have substantial energy transfers with minimal (if any) damage. Here we will discuss the myth of "no damage = no injury" from a vehicle appearance / design point of view and how it relates to injury in a collision.
So as to get into this subject, we need a little history lesson first. With vehicle style being the topic of focus, the industry exploded after World War II. The jet age influenced bumpers, headlights and taillight's fins. Something else happened too, for the first time in the automobile's history, vehicles were more than "around town" horse-less buggies; the power of their engines and speeds potential dawned a whole new arena -- security. In the 1960's vehicle aesthetics began to compromise with safety. Automotive designers started to consider topics like; occupant restraints structural integrity, and crash worthiness.
The industry faced slow growth and change into the 1980's, each revision or change did bring with it progress and progress but not enough at any one time to be a huge leap forward. The changes which were necessary, were too experimental, too cost prohibitive, or just too market risky. Then in the 1980's a revolution in business started to take hold -- the computer. The personal computer allowed for design changes to be done with efficiency. Once plugged in and switched on the days spend calculating double function and variables became complicated than a few clicks.
The computer made it possible for car manufacturers to reduce years of conventional design and research practices into only a month or two and at the same time it allowed for much more cost effective experimentation and new process development.
No Vehicle Damage Doesn't Guarantee No Injuries
Now that We've completed history 101 let Us discuss the topic of Stage - "no damage = no injury"
Vehicle layout, as an approach or concept, has undergone a considerable overhaul in recent years. The change has influenced the use of bumper covers. The long standing tradition in design is to make them of a alloy and to put the outside or separate from the body. (Consider all those classics in "American Graffiti"). The bumper was designed to function as a compliment to the vehicle's appearance. The safety perspective was non-existent with respect as they were no longer than a sacrificial lamb to save the body.
In the early 1970's federal mandates designed to make vehicles safer forced the producers to engineer larger and much more structurally sound designs. The most noted changes where the moving of bumper away from the body itself to an essential part of the car's body. This "afterthought" look borrowed from the truck world was the standard until the late 1980's. Three things changed in the 1980's: First, bumpers began to move to behind urethane bumper covers in usage.
This gave a look to vehicles and assisted with aerodynamics. Because aesthetics were no more part of the equation, bumpers became stronger and included the use of energy absorbing material between the bumper structure and the bumper cover. Finally, automotive paints had also advanced, including the ability to resist cracking & flaking, and paint had become elastic.
These changes also had another positive side effect; because of the elastic properties of urethane and the paint, minor collisions, even those which damaged the bumper behind them, no longer seemed as serious. Often times a bumper cover needed more than some paint and prep, where past designs necessitated changing the bumper.
The largest change between older design and the new one, is the inherent elasticity of the new bumper covers. These covers can, and do, rebound into the design they have been formed in and the use of paint that is elastic means the paint is likely to rebound as well. The assessment of speed from damage is currently poorer while signs of impact are evident. Obviously when a steel bumper is distorted it remains that way leaving no room for underestimation.
Notice how we have not discussed these design changes have gained energy transfer; and this isn't any mistake. There are no groundbreaking points. Changes in vehicle design is not going to ease violation of laws of physics. All these design changes is make the energy transfer in a low speed crash less costly and less apparent.
Evaluating Vehicle Damage
However, there are Just demonstrable measures that can be taken to assess the effects of energy transfer in no apparent damage collisions:
- Remove the cover of the bumper and inspect the materials below the "skin" of the bumper for internal damage
- Check the angle of the passenger seat. The factory at a angle and when the occupant is thrown backwards, often the seat angle changes rendering evidence of force transfer sets seats
- Have the swivel tested with a laser apparatus most repair shops use to make sure the frame of the car is "plumb." Even a 1-degree variation will be evident and often the chassis gets distorted and that requires energy transfer.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.