Expert Witness Blog
Summary: Biomechanics Expert Witness allowed to testify in part even though the plaintiff argued that the experts testimony should be excluded because a model of a head was different than the head of the plaintiff.
Facts: This case (Rogers, Steven et al v. K2 Sports USA et al – United States District Court – Western District of Wisconsin – December 28th, 2018) involves an injury the plaintiff suffered while skiing. The plaintiff allege that the helmet he was wearing, made by the defendant, was designed defectively and that the defect caused the injury. The plaintiffs have sued for negligence, strict product liability, and breach of warranty. The defendant denies that the helmet was defective, arguing instead that the helmet was the wrong size and that Scott had not properly fastened it, and that he was injured by direct contact with the ground. The defendant has hired Biomechanics Expert Witness Irving Scher to provide testimony on their behalf. The plaintiff has filed a motion to exclude this expert from testifying.
Discussion: Scher used computer models to ascertain the fit and looseness of the helmet that the plaintiff wore. In addition, Scher conducted a biomechanical engineering analysis so as determine the kinematics of the accident. The plaintiff argue that both conclusions should be excluded.
Using a 3D computer model of the plaintiff’s head from the CT scans on the night of the accident, Scher calculated the circumference of the plaintiff’s head at 57 centimeters. Scher opined that the plaintiff’s helmet was one size too large. Scher then determined that there was at least 2.25 centimeters of free space between the plaintiff’s head and the interior of the helmet. In addition, Scher viewed photographs of the plaintiff on the day of the accident and determined that the chin strap was loose.
The plaintiffs allege that Scher’s analysis is not reliable because the plaintiff’s head is different from the measurement that Scher reported. The court opines that neither party provides evidence showing that the other party’s measurement is incorrect. Thus, the size of the plaintiff’s head is a matter of genuine dispute, which does not render Scher’s opinion inadmissible.
Scher also offers opinions about how the plaintiff fell and how he was injured. The court opines that it will not consider these opinions as they are too speculative and that there is not enough information about how the plaintiff fell to support Scher’s analysis. The court opines that Scher’s simulation are not admissible because they are based on guesswork rather than on the facts of the plaintiff’s accident.
Conclusion: The motion to exclude the expert witness testimony of Irving Scher is denied in part and granted in part.