Skip to main content

Tag: biomechanics

More on BC Injury Claims and Biomechanical Engineering Evidence


Further to my recent post on this topic, the evidence of biomechanical engineers is becoming more common in BC injury lawsuits.
Biomechanics is the study of forces applied to biological tissue and the injuries that can result from such forces.  In litigation it is easy to imagine the use such expert opinion evidence can be put to in proving causation of injuries.
Biomechanics is a relatively new scientific field.  Courts are generally conservative and can be slow to accept ‘novel‘ scientific evidence.  Despite judicial conservatism, biomechanical evidence does appear to be gaining acceptance by BC Courts as demonstrated in reasons for judgment released today.
In today’s case (More v. Bauer) the Plaintiff suffered a severe brain injury while playing hockey.  The Plaintiff claimed his helmet was negligently designed and sued the manufacturers of the helmet.  In support of his claim he called a biomechanical engineer who gave evidence in the field of biomechanics and the biomechanics of safety standards.
The Defendants did not challenge his qualifications to give this evidence, however, at the conclusion of the expert’s testimony the Defendants brought a motion to rule the testimony inadmissible arguing that the expert’s “underlying methodology and science are so flawed that the evidence (does not meet the legal test for admissibility)” and that the expert was “biased and purposely misled the court to assist the plaintiff“.
Mr. Justice Macaulay rejected the motion and concluded that the evidence was in fact admissible.  In doing so the Court recognized biomechanics as an “accepted area of scientific and academic expertise“.  The Court reasoned as follows:
[1] Dr. Stalnaker has a Ph.D. in theoretical and applied mechanics. Through much of his lengthy career, he has worked in the branch field of biomechanics. He also has practical experience in standards development for certification purposes although not specifically with regard to hockey helmet standards. Biomechanics involves the study of body kinematics ? the forces applied to biological tissue and the injuries that can result. The plaintiffs sought to qualify Dr. Stalnaker as an expert in biomechanics and the biomechanics of safety standards…

[12] Mohan sets out the current approach to the admissibility of expert evidence. Mr. Justice Sopinka outlines the following criteria for the admissibility of opinion evidence:

(1)      the evidence must be relevant to some issue in the case;

(2)      the evidence must be necessary to assist the trier of fact;

(3)      the evidence must not contravene an exclusionary rule; and

(4)      the witness must be a properly qualified expert.

[15] Assessing reliability includes determining whether the science or technique the witness uses to reach a conclusion is “novel”. Novel science will be subject to a stricter level of scrutiny than theories or techniques that are more generally accepted…

[23] To conclude, in assessing reliability when exercising my gatekeeper role, I must determine whether the approach the impugned expert takes is novel. If Dr. Stalnaker is relying on a novel theory or technique, I should exercise a higher level of scrutiny when examining reliability, in order to prevent the trial becoming “a medical or scientific convention with an exchange of highly speculative points of view” (R. v. J.E.T. at para. 77).

[24] In assessing reliability, I may find the Daubert factors helpful, but need not apply them too strictly. The purpose of applying the factors is to determine the degree of uncertainty present in the impugned expert’s analysis. The question is whether “the degree of uncertainty is unacceptable given the likely effect upon the trial process and the trier of fact. The level of acceptable uncertainty may depend upon the purpose for which the evidence is tendered and the use made of the evidence by other experts” (Wolfin at para. 20). Both the mode of trial and the importance of the evidence to making a final determination of the matter are factors to consider. If a theory or technique is implausible it will not be admitted.

[25] I remain persuaded that biomechanics is a recognized and accepted area of scientific and academic expertise. I am satisfied that Dr. Stalnaker is qualified to give opinion evidence in the area of biomechanics including in relation to safety standards. Opinion evidence is necessary to assist me in drawing appropriate inferences of fact.