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Unreliable Methodologies Doom Neck Brace Experts

October 6, 2017 in  News

New York Law Journal 

Weeks ago, a U.S. Magistrate Judge in Indiana excluded the opinions of two experts because they did not meet the “reliability” criteria for expert testimony specified in Federal Rule of Evidence 702 and the famous Daubert decision. The rulings doomed the badly-injured plaintiff’s claim because summary judgment in favor of defendant quickly followed. The preclusive ruling on the experts is found at Lyons v. Leatt Corp. 2017 U.S. Dist. LEXIS 148783 (N.D. Ind. Sept. 14, 2017). The summary judgment opinion is found at 2017 U.S. Dist. LEXIS 149046 (N.D. Ind. Sept. 14, 2017). 

The rulings are lengthy (respectively, 24 and 14 LEXIS pages) and detailed, but the reader should not bail out on reviewing them. There are valuable lessons to be learned. If you are a plaintiffs’ advocate, you will want to avoid the shortcomings in reliability that plagued the experts. If you are a defense litigator, you will want to learn about potential vulnerabilities in your own adverse experts’ reports and methodologies. You can also learn about the relative harmony that should exist between the expert’s report, proffered under Federal Rule of Civil Procedure 26(a)(2)(B), and that expert’s subsequent deposition testimony. And you will want to learn about the significance of an expert’s failure to account for “obvious alternative explanations” to the theory or opinion he or she espouses.

The facts, in a nutshell, are as follows. Plaintiff Brock Lyons was riding his 2013 Honda dirt bike on a track called Wildcat Creek MX. He was practicing for a national amateur competition. He was familiar with the track’s layout, having ridden it nearly one hundred times in the preceding 10 years. He was wearing motor cross garb, boots, gloves and goggles plus a full-face helmet. He also wore a 2007 “Leatt Brace”—a neck brace that he had worn for seven years and never “had a wreck” with this brace.

During the practice run, he lost control and was thrown off the motorcycle as he negotiated a “step-up” jump. He went up the jump at about 40 mph but came down “nose-high,” i.e., touching down on the rear wheel only with the front wheel in the air. Plaintiff was hurled over the handlebars and struck the ground head first with the top of his helmet above the left eye. A fraction of a second after impact, he felt “everything go numb.”

Plaintiff suffered severe thoracic spinal cord fractures at T5-T6, with ejected fragments nearly obliterating his spinal canal, along with “jumped facets,” spinal cord edema and cord compression down to T10. He sued the Leatt Corporation, designer and maker of the Leatt Brace he was wearing, under products liability theories and also claimed gross negligence justifying punitive damages. Plaintiff’s theory against Leatt was that the neck brace restricted his head’s range of motion thereby increasing spinal loading. The brace allegedly restricted the rider’s ability to “tuck and roll” his head, constraints that purportedly increased the potential for axial loading imparted to the spine. .

To prove such allegations, plaintiff retained Tyler Kress, Ph.D., who authored a 27—page expert report in November 2016. He stated his findings and opinions and discussed experiments he conducted at Virginia Tech measuring accelerations and forces in a test dummy “with” and “without” the Leatt brace. Kress stated that, under the test conditions performed, “the use of the Leatt brace does not have a considerable effect on spinal column loading.” (LEXIS at *12—*13). He also wrote that limiting the range of motion of a motor cross rider’s head with a neck brace “increases and focuses compressive loads onto the vertebrae.” Thus, riders are better off not wearing the brace from an overall safety and injury perspective.

Methodologies Flawed

The court said an expert’s report “must include the ‘how’ and ‘why’ the expert reached a particular result, and not merely the expert’s conclusory opinions.” Here, Dr. Kress’ report failed “to set forth the reasons for his opinions and the facts or data he considered in forming his opinions.” (LEXIS at *15-*16). Further, Kress’ report did not disclose that he conducted a so-called biomechanical “surrogate study” using plaintiff himself, taking range of motion measurements, and creating about 270 photographs. The court found the failure to disclose the study and its measurements amounted to “ambush” of defendant when Kress later used the information at his deposition. Plaintiff cannot cure Kress’ deficient report with his later deposition testimony. (LEXIS at *19).

Additionally, the court found that Kress partially based his opinions in this case on reading deposition testimony given by Grant Nelson, a former Leatt employee, in another separate litigation. But Kress never saw facts or data from reports authored by Nelson and, so, Kress’ opinion was advanced without reviewing the scientific basis for Nelson’s statements in the other lawsuit. This failure goes to the reliability of Kress’ opinion (LEXIS at *24—*25).

Kress’ missing methodology for reaching his “Findings/Opinions” was an egregious omission from the Rule 26 expert’s report. Kress failed to provide the “how and why” he reached his result and thus fell short of the requirements of Rule 26. The attempt to cure this flaw at Kress’ later deposition was prejudicial because plaintiff, at the time of the deposition, was already in possession of defendant’s expert witness disclosures. Yet, the defense experts had neither seen nor been able to test the data and methodology of the earlier-disclosed expert. (LEXIS at *27).

Kress’ opinions also flunked the Daubert gatekeeping criteria requiring reliable methodologies and opinions. The reliability analysis does not end with the court’s conclusion that an expert is qualified to testify. Even “a supremely qualified expert cannot waltz into the courtroom and render opinions unless those opinions are based on some recognized scientific method.” (LEXIS at *30). Courts need not accept opinion evidence that is connected to existing data only by the ipse dixit of the expert. A court may conclude that there is “simply too great an analytical gap between the data and the opinion proffered.”

Kress’ opinions regarding the neck brace’s effect on the wearer’s range of motion also were not supported by sufficient facts or data. Although Kress relied heavily on materials from other lawsuits brought by different plaintiffs, he offered no analysis of how those lawsuits were similar to this one. Indeed, he offered no explanation why hearsay communications from witnesses in other lawsuits, not disclosed in this case, would be information on which an expert would reasonably rely in accordance with Federal Rule of Evidence 703. (LEXIS at *32—*33). Additionally, the court reviewed Kress’ methodological flaws. For example, he provided no facts, data, calculations or analysis to show how the forces could lead to the brace causing Lyons’ injuries. (See LEXIS, at *35—*48).

One of the telling points made by the court was Kress’ failure to account for “obvious alternative explanations.” (See LEXIS, at *48-*54). For example, Kress cited multiple scientific and medical research articles demonstrating an alternative explanation for Lyons’ injuries. They showed that the most common spinal injury caused by a severe head-first impact is the very mid-thoracic spine injury suffered by plaintiff.

All the articles were published before Dr. Leatt invented the Leatt Brace. The reasons given for trauma to the spine are anatomical. The driver is catapulted over the handlebars of the motorcycle. The resultant flexion straightens out the cervical spine but accentuates the curvature of the thoracic spine. The forces are then transferred down the axial skeleton until the area of maximum curvature is encountered, the area between T4 and T7. Thus, when Kress’ report cites an alternative theory that is at odds with his own opinion, yet ignores this obvious alternative explanation contained in several of the very sources he cited, the reliability of Kress’ opinion is decreased. (LEXIS, at *53—*54). Because there was too great an analytical gap between the data and Kress’ opinion, his testimony was excluded. Defendant’s motion in limine was granted.

Second Expert

Plaintiff’s second expert was Ryan Hughes, a dirt bike racer for over 30 years, who won some 100 races. He personally experienced hundreds of crashes, including crashes similar to Lyons’ accident. Hughes trains and advises riders all over the world, including children and world champions, personally observing their experiences. He left professional racing in 2013 after fracturing multiple thoracic vertebrae. He was not wearing a Leatt Brace when he crashed.

The court conceded that Hughes was an expert on the sport of motocross based on his specialized knowledge gained through years of personal experience. But was qualified to opine on product design, developmental testing, accident reconstruction, medicine or biomechanics? Could he reliably testify regarding the mechanism of Lyons’ injury and its cause? Hughes’ Rule 26 expert report had asserted: “Every rider that has been paralyzed or has broken their back with one of these untested so-called neck braces, has broken their backs right under the area where the brace stops at T4—5—6 … [I]t was a classic neck brace injury and there’s no way around it.” (LEXIS at *56). Hughes called the device “poorly tested.” Plaintiff was put “in a very dangerous position.” When wearing the Leatt brace, if the rider goes over the front like Lyons did, “you can’t move and tuck your head.” That’s why neck braces are not used in America’s toughest sports like football and hockey

The court held Hughes was not qualified to testify on the technical or scientific topics regarding the mechanism of plaintiff’s injury. Hughes’ opinion, rather, was what he “believes” happened based on his experience. But that does not make him an expert in the technical and scientific areas required by Federal Evidence Rule 703 and Daubert regarding the cause of plaintiff’s crash or injury. He is qualified as a “motocross expert and can give opinions based on that expertise that would assist the jury in understanding the sport of motocross.” But none of those opinions are relevant to the causation issue in this matter. Nor was the expert’s methodology reliable. (LEXIS, at *65—*68). Accordingly, Hughes’ testimony was not admissible.


Strident critics of Daubert reliability criteria that judges use in their “gatekeeping” task to screen expert testimony frequently claim that meritorious cases are wrongly being dismissed. But Daubert and Rule 702 reliability requirements are here to stay—deservedly so. A more positive and helpful approach by advocates would be to view the reliability criteria as a road map to presenting a stronger case. Make reliable methodologies and opinions your ally and friend—not your enemy. The recent decision(s) featured here offer good lessons regarding such an approach.