Open Discussion: Whiplash with Arthur Croft
By Authur Croft
The opinions expressed herein are the guests' alone and have not been reviewed by a WebMD physician. If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.
Moderator: Greetings all! Please welcome Arthur Croft, DC.
Croft, director of the Spine Research Institute of San Diego, has been engaged in whiplash research for the past 18 years. He is the original developer of the widely used whiplash grading system (WAD), as well as widely adopted treatment guidelines for the condition. We will be discussing whiplash.
Good afternoon, Dr. Croft!
Dr. Croft: Good afternoon.
Moderator: Let's begin by defining whiplash.
Dr. Croft: Different researchers define it differently. Some include all types of injury vectors. I confine the diagnosis to rear impact vector crashes.
Moderator: What happens to the neck in these crashes?
Dr. Croft: A complicated question! In a nutshell, the cervical spine is compressed first, then subjected to shear strain. Depending on the relationship to the head restraint and the occupant's position, varying degrees of extension will occur. This back bending of the neck is followed by a forward motion or flexion. This can be accentuated by the use of the shoulder harness because it will abruptly stop the torso, yet allow more forward motion of the head.
Moderator: Many deny the existence of whiplash. Is there conclusive evidence that this condition exists?
Dr. Croft: Those who deny its existence can do so only by denying a huge body of scientific literature. I think what you are saying more likely is that many deny that chronic whiplash, or the so-called late whiplash, exists. To that, I would point skeptics to over 40 outcome studies conducted over the same number of years. These demonstrate that a large proportion of these patients do continue to be symptomatic for long periods of time. In the case of rear impact type injuries, these studies show that, on average, about 50 percent of these persons will continue to have some degree of neck discomfort. About 10 percent will be disabled. In the U.S. there are about 3 million such injuries each year. About 35 to 50 percent of the occupants in the cars are injured, statistically.
Moderator: What exactly is the system that you developed for grading whiplash (WAD) and how does it work?
Dr. Croft: Originally, the system had three parts. The first part defined the type of crash: rear versus side impact, versus frontal or other type. The reason for this is that we have seen that the rear impact variety carries a worse prognosis. The second part was the grading system and it was essentially the same as the one later proposed by the Quebec Task Force in 1995. The third part defined the stage of healing. This system was designed to allow doctors a better means of communicating between themselves and to allow a more reasonable way of conducting research. And, to that end, we have indeed seen that researchers have used this grading system to make their research more meaningful. Of course, it is now referred to as the Quebec Grading System! Nevertheless, it is better to compare Grade 2 patients with Grade 2 patients, than to lump all grades of severity together under the umbrella of "whiplash" as we did years ago. Now we can compare apples and apples.
Moderator: Has that had a positive effect on treatment success?
Dr. Croft: It's hard to say whether it has been helpful directly. We haven't really studied that effect. However, since it provides a lingua franca vis-a-vis research, I think it will at least indirectly have a beneficial effect. In most areas of medicine, similar grading systems are used to aid in diagnosis and treatment, and to assist researchers in their endeavors.
Moderator: Is there any way to prevent whiplash?
Dr. Croft: There are indeed several way to reduce the likelihood of crash and the likelihood of injury (or at least the severity of injury) when crashes are unavoidable. Several companies, such as Delphi and TRW are currently testing intelligent vehicle highway systems, which will monitor your vehicle's position relative to other cars on the road. Using forward looking and rear looking detectors (radar, infrared, etc.), the sensors will determine whether another car is approaching too fast, or whether you are approaching too fact, and will sound an alert to warn the driver(s). Initially, these systems will only be passive. In later development, they may actually be active; that is, they might govern the accelerator or activate the brakes. How many crashes can be prevented by such systems is debated, but even a reduction of 10 percent would save us a great deal of morbidity and health care expenditure. As for the reduction of injury potential, there are advances in auto safety engineering that are promising. Both SAAB and Volvo now have specially designed seats to reduce whiplash loads in rear impact crashes. I am a consultant for a company that makes head restraints and seats and, although I am not at liberty to divulge trade secrets, I understand some cars in the model year 2001 and 2004 so far have been slated to have new safety systems designed by this company. Having said that, the situation currently in the U.S., in general, is pathetic. In 1996 the Insurance Institute for Highway Safety tested 163 cars for effective head restraint geometry and rated only about 3 percent as "good." The rest were marginal or poor. In our crash testing at this institute, we have found, as others have as well, that many times the occupant's head actually ramps up and over the top of the restraint, driving it down as a hammer drives in a nail. This allows the neck to hyperextend. In our test, this is where injury often occurs. These head restraints are now sometimes designed so that they can be put into a down position only by special adjustment hasps, but many cars still do not have these. The fact that our vehicles are so poorly designed is a reflection of the auto industry's fixation on current federal motor vehicle safety standards which require crash testing at 30 mph. To make them crashworthy at those speeds, they must be made relatively stiff for lower collision speeds. That's why low speed crashes are so paradoxically injurious; the collisions at those speeds are almost entirely elastic.