“Do IndyCar Series drivers experience short-term or long-term neurologic consequences from biomechanical forces related to crashes experienced on the racetrack?”

Professional motorsport drivers face a high risk of crashes, which can cause biomechanical forces comparable to those experienced by athletes in contact and collision sports. However, little is known about the potential short-term and long-term neurological consequences  of these impacts on motorsport athletes. To address this knowledge gap, members of the Johns Hopkins All Children’s Hospital/IndyCar Series Research Collaboration analyzed three years of crash data collected by IndyCar, the American-based auto racing sanctioning body for the highest class of open-wheeled, single-seat race cars in the United States — most familiar as the cars racing in the famed Indianapolis 500 and the Grand Prix of St. Petersburg.

“Professional motorsport drivers are regularly exposed to biomechanical forces comparable with those experienced by contact and collision sport athletes,” says research team member Danielle Ransom, Psy.D., ABPP-CN, neuropsychologist and lead author. “While efforts are under way to characterize the consequences of impact-related force exposure in athletes across many contact and collision sports at all levels, little is known about these outcomes in motorsport athletes.”

A recent study conducted by researchers aimed to examine the potential link between cumulative impact exposure and oculomotor functioning in professional IndyCar drivers. The study analyzed IndyCar data collected from 2017 to 2019 and involved 13 IndyCar drivers who had been involved in at least two crashes during the three racing seasons. The drivers, who had an average age of less than 30 years, were fitted with accelerometers in each car chassis and a driver earpiece to measure the impact exposure during each of the 81 crashes that occurred during the three-year period. The study also measured driver oculomotor performance at preseason baseline before each racing season and to detect any changes over time.

The Kart 4 Kids Connection

Although this initial work was aimed at measuring potential crash effects in professional racecar drivers, pediatrics remains an important anchor for the Hopkins-based study members and future directions aim to extend the work to children who participate in motorsports.

Research team member Patrick Mularoni, M.D., director of Sports Medicine and a pediatric emergency medicine specialist at Johns Hopkins All Children’s, believes their research could translate to improved safety for children who participate in motorsport through Johns Hopkins All Children’s relationship with Kart 4 Kids Foundation, a St. Petersburg-based organization benefitting the hospital.

The 12th annual Kart 4 Kids Pro-Am Race, held at Andersen RacePark in Palmetto, Florida, on March 1, 2023, featured professional drivers alongside amateur teams. The event raised $282,000 for Johns Hopkins All Children’s Hospital. Mularoni says Kart 4 Kids has raised more than $1.6 million over the years to help provide critical, patient care equipment for Johns Hopkins All Children’s.

The Kart 4 Kids event, originally established in part to pay tribute to St. Petersburg-based professional racing driver Dan Wheldon, tragically killed in an October 2011 racing accident, also provides support for staff, patients and families. Funds have also supported vital development of the Johns Hopkins All Children’s Hospital Concussion Initiative research lab, whose ongoing work aims to better understand concussion management and prognosis.

Director of the Center for Pediatric Data Science and Analytics Methodology in the Johns Hopkins All Children’s Institute for Clinical and Translational Research Luis Ahumada, Ph.D., who analyzed the IndyCar data, says members of the research collaborative aim to translate their INDYCAR research to benefit children who compete in motorsports, and often from very young ages.

“Many professional racecar drivers begin competing in motorsports by the age of 5,” Ahumada says. “By age 16, many are driving professionally and, by age 30, many are ready to retire.”

According to Ransom, “Tracking key indicators of brain health over a long period of time at all stages of sport participation is critical to understand any potential consequences of impact exposure that begins within the moving target of development.”

Enter Terry Trammell, M.D.

The study was launched with the help of Terry Trammell, M.D., IndyCar Series driver safety advocate. Trammell, a member of the Motorsports Hall of Fame for his pioneering work in IndyCar driver safety, is credited with saving countless lives through a data-driven approach combining engineering principles and medical expertise to improve trackside response. An orthopaedic surgeon, he is known for revolutionizing racetrack emergency services and has been active in trackside medical care since 1973. He now serves as a consultant to Indianapolis Motor Speedway.

Trammell is also a founding member of the International Council of Motorsports Science and the FIA Institute for Motorsport Safety and was awarded the 2021 Louis Schwitzer Award for biomedical engineering advances for driver safety. In 2023, he was inducted to the Motorsports Hall of Fame of America.

In collaboration with IndyCar Medical, Trammell has played an instrumental role in the development of their robust concussion protocol. This comprehensive protocol encompasses a wide range of measures, including preseason baseline physical, neurocognitive evaluation, and oculomotor exam. Moreover, it outlines specific procedures that must be followed in the event of a suspected concussion following a crash. According to Ransom, Trammell's expertise and senior leadership have been invaluable in putting the unique data gathered from these evaluations into context and providing crucial insights into a driver's health during trackside examinations.

“To our knowledge, no studies have been published that explore neurologic outcomes in professional motorsport drivers in any series,” Ransom says.

The Study

The Johns Hopkins All Children’s Hospital/IndyCar Series Research Collaboration recently published the results of its first investigation exploring the relationship between crash events and neurologic consequences in drivers from the IndyCar racing series. Their research paper, titled “Longitudinal Outcomes of Cumulative Impact Exposure on Oculomotor Functioning in Professional Motorsport Drivers,” was published May 2, 2023, in the Journal of the American Medical Association’s “JAMA Network Open.”

The purpose of the study was to determine whether cumulative impact exposure was associated with oculomotor functioning in professional IndyCar Series drivers. Data from accelerometers in each car chassis and driver ear piece measured impact exposure during each crash (a total of 81 across the three seasons). The researchers combined crash data with driver oculomotor performance measured at preseason baseline before each racing season to explored any associated changes over time.

Concussion Concerns

As motorsports continue to gain popularity, so does the need to identify and address concussions in athletes. Efforts to identify athlete concussions have recently taken on great importance in motorsports, Mularoni says. For example, the FIA, motorsports’ governing body, co-sponsored the most recent International Consensus Conference on Concussion in Sport held in Amsterdam in October 2022, alongside the International Olympic Committee, Fédération Internationale de Football Association (FIFA), International Federation for Equestrian Sports (FEI), World Rugby (WR) and International Ice Hockey Federation (IIHF). Although the consensus is not yet published, past consensus recommendations from the separate Scientific Committee have identified the importance of multidimensional screening to the short and long-term consequences of acceleration/deceleration and rotational forces during a contact incident. Accordingly, IndyCar concussion protocols mandate that its drivers who experience extreme head acceleration (80Gs) — be evaluated.

Concussion protocols consistent with this international consensus statement have been adopted by all major governing sporting organizations. Under Trammell’s direction the IndyCar series has developed concussion policies and procedures for preseason baseline testing, trackside assessment, and return to racing. Drivers are to be medically evaluated if head accelerations sustained during a contact incident exceed the gravitational force threshold of 80Gs.

For drivers involved in crashes exceeding 80Gs or those who seem “off” after a crash, evaluation with reliable and valid multidimensional tools is critical to ensuring safety of the entire driver field, Ransom says.

Once more, a driver’s return to racing should be based on expert evaluation that considers the full range of tools comparing a driver’s post-crash functioning to preseason baseline.

Understanding the acceleration forces experienced by drivers during a crash event is also important for research on concussive and sub-concussive blows (known in a popular racing docuseries as “micro-concussions”). For over two decades, IndyCar Series drivers have been equipped with custom-fitted accelerometers placed in the ear canal with a six-axis measurement to measure these forces.

The study team used data from ear pieces and a separate accelerometer uniformly fixed to the floor of the IndyCar chassis near the center of its mass. IndyCar also employed the Accident Data Recorder, third generation (ADR-3) data collection system for ear and chassis accelerometers since 2010. Events, such as crashes or other contacts were recorded when sensors were triggered by a 5G acceleration in any axis and stored in the ADR-3 data log.

Data Analysis

“We analyzed three sets of data,” Ahumada says. “One set came from the chassis recording crash events during practice, qualifying and racing. Another data set came from sensors placed in the drivers’ ears, and the final dataset came from the ocular vestibular reflex testing (OVRT) performed by the drivers.”

The data recorded peak resultant acceleration and deceleration forces in lateral, longitudinal and vertical planes. ADR-3 chassis and ear recordings and crashes from practice sessions, qualifying events, and races were used as indicators of cumulative impact exposure. Contact incidents were monitored in real time by IndyCar Race Control and confirmed by review of ADR-3 data, crash damage inspection, and video by IndyCar accident investigation personnel.

The huge volume of data they received reflected datapoints from crash events occurring in milliseconds.

Conclusions — The Good News

“We hypothesized that greater impact exposure would be associated with a relative decline in oculomotor functioning over time,” Ransom says. “However, the findings did not support our hypothesis as we did not observe statistically significant associations of cumulative impact exposure or racing season assessed with oculomotor performance over time.”

The researchers wrote that they found “no statistically significant associations between cumulative impact exposure and oculomotor performance” and that their findings “reflect the relative stability of oculomotor performance despite exposure to the highest levels of cumulative impact conferred through multiple crashes over a three-year period.”

In other words, their findings suggest that IndyCar is doing very well in its efforts to protect its drivers from neurological damage resulting from crash events.

“We want to take this data from professional events and translate it to the youth racing circuit for children who drive much smaller cars, but who aspire to be like their IndyCar heroes,” Mularoni concludes. The study team aims to promote safe participation in the sports and activities their patients love.

Ransom added that the team will be continuing their collaborative research and are planning to analyze more IndyCar data collected over a longer period of time using a range of multidimensional tools as potential indicators of brain health.