Academy of Chiropractic’s

Lawyers PI Program


 From the Desk of:


"2.49 mph Threshold for Injury"


It was previously thought that threshold for injury was 6.8 mph in a report by Richter (2000) and that reference has been the standard for many years. Arthur Croft, the director of the Spine Research Institute of San Diego, has also reported that although cars are rated to deform and 5 mph (delta V), most cars deform between 8-10mph.

These sets of facts bear out that the occupant gets injured prior to the car deforming. In addition, Hijoak, Narusawa & Nakamura (2001) determined that significantly more people were injured when there was no damage to the vehicle than when the car was considered "totalled." In understanding the damage in crashes, when the cars deform, the released energy is in the form of heat and sound dissipating the amount of energy translated to the occupant.

This paradigm is poorly understood by lawyers, jurors and justices nationally. In fact, this is one of the "hottest" topics when I lecture to lawyers across the country and even in those regions I have lectured to multiple times, many of the lawyers still cannot grasp the concept because they have been brainwashed by the rhetoric of the defense lawyers in court and have "drank the Kool-Aid" of nonsense. The ongoing belief is that if there is no damage to the car, then the occupant cannot be hurt and that simply is not true.

When understanding the "business of the lawyer," there are a few things to consider. First, they all strive for head trauma and brain injury cases. Those are their "holy grails" and where they make the most money. It is like us wanting the PI cases and it is for that reason that I created the Head Trauma/Brain Injury course; so that you can be versed on brain trauma pathology to be able to consult lawyers on those cases. Although it is a rarity that any of those cases will end up in your office, many lawyers need a reference to go to, you, which becomes a huge "relationship builder."

The next most pressing item on the lawyer's agenda is the no-damage crash and bodily injury. Too many lawyers are walking away from these cases with too many people being hurt and it is our job to educate the medical-legal community on the truth. This is part of the reason that I created the Accident Reconstruction course. Without those credentials, you will be hard-pressed to get any evidence accepted into testimony regarding the causality, ensuing damages and clinically correlating the bodily damage. This concept is critical to understand and communicate to the lawyers.

Back in 1998, a relatively ignored research finding by J. R. Brault, Wheeler, Siegmund, and E. J. Brault (1998) stated at 4 kph (2.49 mph), crash victims experienced cervical and headache symptoms. The authors claimed the severity and duration was relatively short, but were similar to those of 8 kph crash victims with more research being needed. They stated, "The empirical evidence gained from this experimental study contributes to the construct validity by establishing causal relationship between rear-end collisions and clinical signs and symptoms" (Brault et al., 1998, p. 79).

Causal relationships are a critical component of admissibility to lawyers in every state and the no-damage crashes raise serious questions. It is your responsibility as THE "medical-legal educator" to raise the awareness of the courts and individual lawyers and become their "go-to" person with these types of cases. Make sure you are credentialed so the lawyers CAN USE you. Otherwise, you will be a wonderful source of knowledge that no one will or can work with.

This entire consultation has been put in a format for the lawyers in bimonthly flier #101.


1. Richter, M., Otte, D., Pohlemann, T., Krettek, C., & Blauth, M. (2000). Whiplash-type neck distortion in restrained car drivers: frequency, causes and long-term results. European Spine Journal9(2),109-117.

2. Hijioka, A., Narusawa, K., & Nakamura, T. (2001). Risk factors for long-term treatment of whiplash injury in Japan: Analysis of 400 cases. Archives of Orthopaedic and Trauma Surgery, 121(9), 490-493.

3. Brault, J. R., Wheeler, J. B., Siegmund, G. P., Brault, E. J. (1998). Clinical response of human subjects to rear-end automobile collisions. Archives of Physical Medicine and Rehabilitation, 79(1), 72-80.

Please note that the full text will only be available for #3. You can ask Alli for the article that supports flier#101.