Whiplash Protection

Whiplash and whiplash-associated disorders (WAD) refer to various injuries of the neck that occur as a result of sudden extension and flexion of the neck from unexpected head movements. In most cases, WAD are not usually life threatening but can impact quality of life on a long-term basis significantly.

It is strongly associated with road accidents and particularly rear-end collisions. As a result, some vehicle manufacturers have researched the biomechanics of common road accidents and developed seats with enhanced protection against WAD.

Causes of Whiplash

Physiologically, vigorous movements of the head that cause damage to the ligaments and tendons in the neck are responsible for symptoms of whiplash. These are commonly stretched or torn that usually take some time to repair to full strength although, in some cases, never return to full strength.

There are various causes of WAD, including road accidents, contact sports and falls that involve head injuries. Of these, automobile accidents are the most predominant cause, which explains why whiplash is commonly associated to road accidents. Although sudden movements of the head in any direction may cause whiplash, read end crashes most commonly result in WAD.

Head Restraints

Initial methods to protect the neck and prevent cases of whiplash focused on car seat design, particularly with the introduction of head rests that are designed to restrain the head in dangerous situations.

However, this approach assumes that mechanical factors are the direct cause of WAD and do not consider other related areas of the body, such as the spine. Current research suggests that head restraints offer a small reduction in the incidence of whiplash by about 5-10%.

WHIPS - Volvo’s Whiplash Protection Study

Volvo undertook the most comprehensive study that examined the effect of specific protection systems of whiplash and whiplash-associated disorders. It focused primarily on rear end car impacts and involved the use of their protective systems to avoid or lessen the severity of whiplash.

The research extended over a period of more than ten years and studied the cause of neck injuries and possible protective systems in great detail. It included comprehensive data about road accidents and research about how these accidents occurred, which led to the development of seats with superior protection against WAD.

Knowledge of biomechanical injury mechanisms that tend to lead to whiplash were interpreted and explained. This then led to the design of a whiplash protection seat, which was tested using the rear end impact dummy, BioRID.

This study concluded and demonstrated that with adequate accident and biomechanical research, a seat can be designed to help protect the neck and spine from low to moderate impacts.

Efficacy of Protection Mechanisms

As whiplash injuries can present with significant symptoms that may continue for varying lengths of time, the development of mechanisms to offer protection from WAD is an important step.

The seats offering high protection appears to reduce risk by more than 50%, although it is difficult to estimate real-life results, as not all consumers opt for seats with these safety features.

In addition to general safety protection principles, it is important to consider individuals that may occupy the seat and the various heights, position and postures of these people. The WHIPS-seat can help to provide considerable protection, but may need to be redesigned slightly for specific occupants.

Although steps are being made in the right direction to improve road vehicle safety and reduce risk of WAD, further developments can still be made to improve safety technology in the future.

References

• http://www.ncbi.nlm.nih.gov/pubmed/10688487
• http://www.driveandstayalive.com/articles%20and%20topics/safety%20equipment/article_volvo-WHIPS-whiplash-protection-system.htm
• http://www-nrd.nhtsa.dot.gov/pdf/esv/esv20/07-0468-O.pdf
• http://www.trafikverket.se/contentassets/955dd108474b4f289eddeeb2c49fe0b5/assesment_of_whiplash_protection_in_rear_impacts_2004.pdf