ATV Expert’s Biomechanical Testimony Permitted Despite Lack of Formal Degree

    Court: United States District Court for the Eastern District of Missouri, Eastern Division
    Jurisdiction: Federal
    Case Name: C.C. v. Suzuki Mgf. Am. Corp.
    Citation: 2018 U.S. Dist. LEXIS 137022


    This case involves an all-terrain vehicle (ATV) accident. The plaintiff claimed the handlebar grip of his ATV slipped off while he was driving, causing him to lose control of the vehicle. The ATV then tipped over and the exposed handlebar impaled the plaintiff’s left leg. The plaintiff filed a product liability and negligence suit against the defendant, the ATV maker. The defendant retained an ATV expert witness to support their case.

    The ATV Expert Witness

    The ATV expert witness was a mechanical engineer with expertise in automotive control, stabilization, balance, crash repair, and safety systems for various vehicles, including ATVs. The plaintiff sought to exclude defense’s ATV expert witness testimony, arguing his views applied directly to the cause of the original incident and were therefore unrelated to this enhanced injuries lawsuit. The plaintiff also alleged the ATV expert’s opinions on biomechanics and human factors went beyond the limits of his knowledge. Specifically, the plaintiff contended that the expert was not qualified to give opinions on whether the grip was correctly applied, the warnings on the ATV, or whether a second rider was on the ATV when the accident occurred.

    The defendant responded that their ATV expert was familiar with ATV safety systems and was endorsed by the ATV Safety Institute, and, thus, qualified to opine on ATV safety warnings. Additionally, the defendant argued that the expert was qualified to testify regarding common ATV manufacturing practices and whether the handlebar grips had been adequately secured. The defendant cited the fact that the expert was an ATV enthusiast himself and had expertise evaluating ATV performance while riding under numerous conditions and utilizing grips.

    Finally, the defendant argued that their expert was qualified to discuss the effect of a second rider on the ATV even though it involves biomechanics. The defendant claimed this was because the expert’s opinion focused on gross biomechanics and he had extensive research experience in biomechanics from a postgraduate program in mechanical engineering.


    The court found that the expert was sufficiently qualified to testify as an expert, even in the absence of a formal degree in biomechanical engineering. The court also noted that the expert was not an expert in human factors, but he had sufficient experience to provide opinions on the lack of warnings on the ATV and how the second rider would affect the ATV during the accident. The court asserted that the plaintiff’s complaint could be sufficiently addressed during cross-examination.

    The court, however, prohibited the ATV expert from testifying on how the mechanics of how the rubber grips were attached to the handlebars. Though the expert had experience riding ATVs, he had not worked in the ATV manufacturing industry and, thus, was not qualified to give opinions on what is popular among manufacturers. His other technical opinions on ATV manufacturing were also excluded.


    The motion to exclude the ATV expert witness’s testimony was granted in part and denied in part.