Hayes + Associates Analysis Contributes to Settlement of its First Horse Jumping Case

Hayes+Associates inspection photo of a “fixed” cup used to assemble jumps for equestrian events.

Equestrian eventing, which involves horses and riders jumping over obstacles of various heights and widths, is reported to be the riskiest of all horsing activity. A horse weighs approximately 1,000 pounds, travels up to 40 mph, has the ability to act independently and is by nature unpredictable. The rider often weighs as little as 100 pounds, sits astride the horse with his or her head up to 13 feet above the ground, and continues to travel at the speed of the horse even when the horse’s speed abruptly slows or stops.

Based on statistics from 2001-2003, over 100 thousand non-fatal, horse-related injuries are treated annually in American emergency departments. The most common mechanism of injury is a fall, with fractures and traumatic brain injuries the most common diagnoses.

In 2017, Hayes + Associates was retained on behalf of an Oregon horse jumping facility to investigate head and spinal cord injuries sustained by a 100-pound teenaged rider during a jumping event. In this instance, the rider was propelled forward over her horse’s neck when the horse tripped over an oxer (a jump of two fences placed parallel to one another with a space between to make the jump wider). Failing to clear the jump, the horse’s foreleg landed between the rails of the oxer, its forward momentum was slowed, and the rider continued headfirst beyond the jump, at which point she was struck by the falling horse. The horse was uninjured.

A case was brought by the rider’s family against the eventing venue, alleging that the facility was responsible for the severity of the fall and injuries because of its failure to use a safety feature known as “breakaway cups.”

In oxer construction, the cups holding the ends of the rails to the verticals can be of two types—fixed or breakaway, the latter of which are designed to allow the rails to more easily disengage from the verticals with downward pressure. Both types of cups allow rails to fall away when met with forward, horizontal force of horse and rider. Plaintiff contended that the cups holding the ends of the horizontal rails were not of the breakaway type and that the severity of the fall and injury would have been reduced or avoided if breakaway cups had been used.

Frame by frame analysis of cell phone video of the fall, conducted by H+A Engineering Associate, Kristen E. Lipscomb, Ph.D., and a physics-based reconstruction of the fall and subsequent injuries by Drs. Lipscomb and CEO Wilson C. “Toby” Hayes showed instead that the rails disengaged from the fixed cups as intended when the horse’s legs contacted them, and that the horse’s stumble, fall, and impact with the prone rider would not have been altered by the use of breakaway cups.

As a result, in part because of the Hayes+Associates biomechanical analysis of the incident, the parties settled prior to going to trial. Based on the experience from this first equestrian case, H+A learned that the same fundamental scientific approaches we employ to investigate more traditional cases, like slips and falls and occupant injuries in motor vehicle collisions, can also be used productively, and successfully, in unconventional cases such as rider injuries in equestrian jumping events.

Predicting Osteoporotic Spine Fracture Risk: Hayes+Associates CEO 1985 publication ranked number 23 of 100 most influential publications on spinal fractures since 1953

Hayes+Associates CEO Wilson C. “Toby” Hayes, Ph.D. was recognized in the March 2019 Journal of Spine Surgery as a co-author of one of the 100 most influential spine fracture publications in over half a century of spine fracture research. Hayes led the research team and co-authored the paper Prediction of Vertebral Body Compressive Fracture Using Quantitative Computed-Tomography  when he was Director of the Orthopedic Biomechanics Laboratory at Harvard’s Beth Israel Hospital. The research helped set the stage for using radiographic imaging to assess risk and prevent fractures of the osteoporotic spine.

 In the paper, the authors showed that there were strong correlations between a widely used clinical method for imaging the spine (CT) and both the density and strength of the bone in human cadaveric vertebrae. The results set the stage for later studies that demonstrated similar strong associations between other radiographic imaging methods and fractures seen clinically in living patients. Diagnostic methods based on this early work and subsequent research by others are now used routinely in the prediction, diagnosis and treatment of spinal fractures, including those resulting from osteoporosis.  

 The lead author, Robert J. McBroom, MD, was at the time a research fellow in the Beth Israel laboratory. He is now a practicing orthopedic surgeon in Mississauga, ON, Canada. Additional co-authors were W. T. Edwards, R. P. Goldberg and Augustus A. White III, MD (then the Chairman of Orthopedics at Beth Israel and currently the Ellen and Melvin Gordon Distinguished Professor of Medical Education at Harvard Medical School).

 The study was funded by the National Institutes of Health, the Maurice E. Mueller Endowed Professorship of Orthopedic Biomechanics at Harvard Medical School (Dr. Hayes) and by the Angus Foundation, Wellesley Hospital, Toronto, Ontario, Canada (Dr. McBroom).

 Hayes+Associates, Inc. (http://www.hayesassoc.com) is an expert witness and consulting firm, based in Corvallis, OR.  The company brings more than 75 years of collective experience in academic research, university teaching and forensic testimony to practice areas that include vehicle collisions, premises safety, slips and falls, products liability, worker safety, sports and recreation, patent litigation and criminal matters.

Hayes+Associates Biomechanics Analysis of Fatal Bike Crash Contributes to $490,000 Settlement

Photograph showing a dangerous condition created when a bicycle tire becomes lodged in the flange gap between a street trolley track and the road surface.

While overall individual and public benefits to cycling are considerable, the interaction between bicycle tires and street trolley/railway flange gaps are notoriously dangerous and sometimes deadly.

In 2018, the family of Desiree McCloud brought suit against the city of Seattle, claiming that street trolley lines were responsible for their daughter’s death when her front tire became lodged in the flange gap between the street trolley track and the road surface, directly causing her to crash. The family further claimed that the city had been aware of the existence and danger of these gaps but had failed to protect cyclists from them, despite knowledge of an easy fix using rubber flange inserts.

A Seattle Police Department report released at the time of Desiree’s 2016 fatal crash stated, “This incident, though obviously tragic, appears to be the sole result of some form of operator error on the part of McCloud.”

The family retained Seattle law firm of Campiche Arnold, who in turn solicited a report from Hayes+Associates (H+A), a Corvallis, OR consulting firm specializing in injury biomechanics. In the report, H+A Associate, Erik Power, P.E., evaluated the crash based on engineering, rider dynamics and injury biomechanics. Power, a fully-accredited traffic accident reconstructionist, and H+A CEO, Wilson C. “Toby” Hayes, Ph.D., reviewed police and medical records and surveillance video captured moments before the crash. Their conclusion: “The streetcar track grooves were the cause of her bicycle accident and ultimately fatal injuries.”

In a pre-settlement press release, Phillip Arnold described the streetcar tracks as a “lethal bicycle trap.” Armed with the H+A analysis of the crash, Jeffrey Campiche maintained, “the only thing that would turn the bike over like that is the tire in the slot.”

The issue involving bicyclists and street trolley track flange gaps is not a new one. A 2010 suit against the city of Seattle was brought by six cyclists who had experienced crashes on tracks. In that bench trial, the city was found not liable. A Portland, OR survey of 1,520 cyclists revealed that over 67% of riders had crashed as a result of riding over street car lines.

In the McCloud case, the H+A analysis was instrumental in rebutting the police assessment of the incident and helping the parties reach the $490,000 settlement.