This defence tactic is very flawed and, in my view, following a voir dire, can be excluded from the Court’s consideration, especially in a trial with a jury.

I will, through a point form presentation, attempt to assist you in attacking this evidence.

1. The studies do not usually give the height or weight of the volunteer subjects and therefore may bear no relevance to the plaintiff in your case.

2. Most studies do not include female volunteers and therefore may bear no relevance to the plaintiff in your case.

3. None of the test subjects had (reported) pre-existing conditions; e.g., degenerative spines (some probably did, but not reported), prior discotomy, or other prior surgery of relevance, fibromyalgia, etc.

4. The position of test subjects in the driver’s seat is never discussed. Therefore, one can reasonably ask whether seat posture (turned to one side or another), or preparedness, would make a difference. The latter item references the fact that the test subjects, knowing they are about to be hit, brace themselves with their arms and legs, and perhaps move their necks flush with the head rest, etc., thereby enabling them to minimize the movement of their body through flexion and extension.

5. Does the expert, through whom the study is introduced, have training in biomechanics?

6. Some experts (and studies) calculate only the average Delta V applied to the plaintiff’s vehicle, rather than the peak force, which is usually two times the average. As well, the experts (and studies) often fail to analyze the forces applied to the plaintiff, rather than the vehicle. To calculate the forces on the driver, the defence expert must know the height and weight of the plaintiff, their exact position in the seat, the position of the head rest, whether the plaintiff was looking to the side or straight ahead, whether the head was bent or upright, and the capacity of the seat itself to absorb shock. Generally, defence counsel do not understand this, so that much of the information is not obtained on discovery and, therefore, unavailable to the defence expert.

7. Indeed, author, Bruce H. Stern, in the July-August 1999 issue of “The Trial Lawyer” notes that, “some defence experts misuse computer programs when calculating the Delta V”. (Indeed) two programs typically used by defence experts specifically warned, “These programs are best suited for studying collisions in a test range for Delta V, approximately 10 – 40 mph. Results outside this range may be suspect.”

8. If there is a lack of similarity, known or otherwise, between the test subjects and your client, the argument is open to you that this is no better than the cases involving junk science (see the U.S. decision in “Daubert” and the Canadian counterpart, “Mohan”, and cases which have followed). In the U.S., the Virginia Supreme Court has held that, “where tests are involved, such testimony should be excluded unless there is proof that the conditions existing at the time of the tests and at the time relevant to the facts at issue, are substantially similar. (For other U.S. cases on point, see the Stern article referenced above.) Therefore, it would seem the Court does not even have to conclude it is junk science. You should determine therefore the source of the study, whether it was published in a peer reviewed journal, and whether it represents widespread acceptance in the scientific community. To the best of my knowledge, injury causation is not a recognized science that is taught as a separate academic discipline. You might also want to find out who sponsored the test being used and whether they had an interest in the outcome.

9. Another question to raise, as was done in another U.S. decision, is whether the studies used are sufficiently broad or peer reviewed to gain general acceptance in the field of biomechanics.

10. Oftentimes, the cars involved in the collision are not available when the defence expert is retained. They, therefore, have to calculate Delta V from photographs, repair estimates, etc. This creates a second point of uncertainty in the evidence, namely, to what degree the Delta V calculation is necessarily accurate.

11. The ultimate argument, it seems to me, is simply one of common sense. We know that no two people are alike and, for that reason, things such as voiceprints, fingerprints, DNA, and other areas of accepted science, confirms this fact. Therefore, since we know that an individual’s psychological response (i.e., those who do not want to be in an accident versus those who volunteer for tests) is completely unique, so that once we are into a chronic pain case, the test, it seems to me, would have no relevance.

To quote from a good friend of mine, Peter Keith, from Alberta, who is an accident reconstructionist, “These tests provide a useful guideline for the level of Delta V above which some level of injury is more probable. But they cannot be used as a predictor of occupant injury in cases where the level of Delta V may be within or below the threshold levels reported by specific human volunteers in carefully staged collisions. The same levels of Delta V can produce symptoms in one individual but not in another, or produce different physical symptoms for the same individual under slightly different circumstances of posture, physical condition, accident scenario, etc. The ultimate test of whether an occupant was injured in a collision is whether he or she experienced physical symptoms after the accident that were not present before. This is an area that can only be addressed by medical experts, not by engineers.