When the Virginia Tech Helmet Lab unveiled its equestrian helmet ratings in 2022, they were lauded as groundbreaking but also criticized by some helmet manufacturers for being incomplete.

Now, Virginia Tech researchers have conducted additional testing using a different method and combined it with their previous results, and they have subsequently revised and updated the school‘s equestrian helmet ratings. Dr. Barry Miller, the helmet lab’s director of outreach and business development, said the equestrian helmet ratings are now based on the most extensive test protocol the lab has ever used, for any kind of helmet. 

The helmet lab has a patented rating system that scores helmets for different sports based on their likelihood to prevent concussions and then assigns them a one- to five-star rating based on that score. Riding helmets have always had to meet a pass/fail test for longstanding certification standards (like ASTM International and Snell), but the Virginia Tech ratings ranked how the helmets performed under controlled testing for the first time.

Some helmet manufacturers felt the original testing methodology was incomplete, including Mips, the Swedish company behind the patented MIPS (multi-directional impact protection system) helmet technology.

“At Mips, we welcome the new benchmark initiative to evaluate equestrian helmets, yet aspects of the test and rating methods leave room for improvement,” Peter Halldin, Mips’ co-founder and chief science officer, said in a statement shortly after the helmet ratings were released in 2022.

The company suggested the lab should adopt additional testing methods, and said Virginia Tech’s testing was too focused on vertical velocity (as when a rider falls straight toward the ground) and did not take oblique and rotational impacts (as when a horse and rider have speed carrying them forward during a fall) into account as well.

It was a deliberate decision Virginia Tech researchers made at the time, Miller said; they excluded horse-racing falls, which tend to have a high degree of horizontal velocity, due to a lack of data about those types of falls.

“Out of the 100 video falls that we reviewed [for the original 2022 study], there wasn’t a lot of horizontal velocity, and so we had no scientific data to support an oblique test,” Miller said. “There [is some horizontal velocity] from the videos but not enough to quantify what that velocity would have been, so we just didn’t have any data to support including those.”

FEI Recommendations Instigate Change

The original testing at Virginia Tech employed a pendulum impactor, which measures the effects of a direct impact on different areas of the helmet. The researchers tested three locations on each helmet model at two different energy levels (simulating a lower and higher force of impact).

In December 2023, a Fédération Equestre Internationale Helmet Working Group put forth a set of recommendations intended to reduce concussions at the FEI levels by 50%. Among the recommendations was the adoption of an oblique impact test for helmets—dropping the helmet onto a 45-degree angled surface covered with a rough material—because it “better reflects real life rider fall scenario[s] and helps reduce risk of concussion injury,” according to the group’s report.

With that recommendation, and armed with data the FEI assembled quantifying what happens in higher-speed falls, such as those in racing and upper-level eventing, the helmet lab researchers set out to determine whether using an oblique impact test would provide new information.

“Equestrian is unique in that there are a lot of different disciplines and types of events that they do, and there are a lot of different ways riders can hit their heads,” said Dr. Steve Rowson, director of the helmet lab and an associate professor in the Department of Biomedical Engineering and Mechanics at Virginia Tech.

“We focused on one type—kind of what we would call a low-speed fall, fall from height. But I think one of the things we really got criticism for is that we didn’t include when the horse is moving at a higher speed,” he continued. “FEI made some recommendations based on their science that … they wanted to see an oblique drop test, and that’s where we drop a head form on an angle. The reason we do that is because it can simulate both downward and forward velocity during the fall, and that’s a very reasonable thing.”

So, researchers at the helmet lab conducted a new study using that method. “If we compare these two test conditions, they generate rotation in a different way; they both have rotation of the head when you hit it, but the angle the force engages the helmet a little differently,” Rowson said. “So if we compared our pendulum results to our oblique drop tower results, it gave us unique information, and that’s relevant to more disciplines than just what we initially focused on. So to me, it made a lot of sense to continue to evolve the method to include this higher speed condition.”

The new rankings are now based on how helmets perform in both tests. This video from the Virginia Tech Helmet Lab shows both testing methodologies in action:

Methods Matter

Why is that oblique test so important? Because it’s a way to better approximate the energy produced—and potentially inflicted on the rider’s head—during falls that happen at a canter or gallop.

“Ultimately with helmet design, from a safety point of view, we’re trying to reduce the transmitted energy from a fall or a kick or anything else to the brain,” said FEI Medical Committee Chairman Mark Hart, MD, a member of the FEI Helmet Working Group. “So anything that can be done that reduces the energy transmitted, it’s going to be a safer situation for the athlete, whether they ride bikes, whether they ski, whether they ride motorcycles or ride horses.”

“There’s a component of forward motion that adds a lot of kinetic energy as you’re moving at maybe 300 meters per minute, or 600 meters a minute. And that’s in addition to the impact energy that would come just from dropping from a certain height, the potential energy of impact onto the ground,” said David Vos, Ph.D., an amateur eventer from Delaplane, Virginia, and chair of the FEI Helmet Working Group. “When you think of the typical impact when you’re moving forward, because the helmet or the head would strike the ground typically on a tangent—sort of on the edge of the helmet, the outer edge of the helmet—the transmitted energy is both rotational and translational [or in a straight line].

“So all we [in the FEI Helmet Working Group] were trying to accomplish was to say it’s not good enough to just think of a pure linear impact that’s dropping straight down, because that doesn’t add any means of considering the rotational component,” he continued.

The oblique test, which Vos emphasized is a representative test and isn’t intended to replicate real-world test conditions, “Can impart both translational and rotational energy, and that is much more representative of what is going to cause damage to a brain. So we want to make sure that helmets are tested to at least meet some thresholds that obviously are never perfect, but at least set a bar to try to consider both of those components in causing brain injury or concussion.”

Vos said he was encouraged to see entities such as Virginia Tech accepting input and then doing additional research to consider the value of other methods.

Hart added that when considering how helmets perform in testing, consumers shouldn’t think that there’s a cut-off line above which helmets are safe and below which they’re not.

“It’s a relative scale,” he said. “Ultimately, we would like, as new materials become available and new designs become available, that we can reduce [risk] even further. Right now, with the materials that are available, you can’t get the risk down to zero; the helmet would be 3 inches thick, and nobody’s head could hold it up.”

Members of the FEI Helmet Working Group and the Medical Committee are sensitive to the practical considerations of helmets, Hart said, including cost and the frequency with which riders want to replace them as new technologies emerge and certifications potentially change.

“This [revision of the helmet ratings] is a progressive step,” he said. “There are going to be new materials and designs in the future. We will need to continually update the standards to make it even safer in the future. So it’s a dynamic process and will evolve over time.

“We have to continually look at it, but again, allow enough time so you’re not buying a new helmet every two years, and give manufacturers enough time to incorporate these changes to make these safer helmets,” he continued. “We have to make sure that helmets are available, and that they’re at a reasonable cost. And I think those are some of the factors that come into how stringent you make requirements and how quickly requirements happen.”

From a rider’s perspective, he added, what’s important isn’t necessarily always having the latest and greatest helmet technology.

“If you’re wearing a certified helmet, that’s the most important,” Hart said. “And not only having that helmet but wearing that helmet correctly. One, wearing it whenever you’re on a horse, that doesn’t always happen, because remember, most injuries do not happen at competitions, they happen at home. And secondly, wearing it properly with the chin strap on, making sure the helmet fits properly, because you can have the best, safest helmet in the world, and if it’s not worn properly, it’s not going to be as effective.”

What’s Next At The Helmet Lab?

“Our general philosophy [is that] we publish ratings with incremental science. So at any given time of a release [of ratings], the methods that we developed are based on what I would call a state of the science, or what we know at that point in time,” said Rowson. “With that said, and this is true for every single type of rating we do for helmets, as we learn more, we’re going to update our methods.”

The first iteration of the helmet ratings was a major step forward, Miller said, because it included rotation head kinematics (how the head rotates during and after impact), rather than just linear movement. Helmet certifications use linear acceleration as a threshold to pass, he explained, “but we know, and the research clearly shows, that rotational head movements contribute to concussion risk as well.

“With this [second study], I think the big jump was now we included falls with lots of horizontal velocity, which is a pretty severe oblique impact—45 degrees on sandpaper from 6.5 meters per second, that’s a pretty injurious impact scenario,” Miller said. The FEI recommendations for helmet performance in this test are “a pretty aggressive performance threshold, so I think that’s great,” he added.

“As far as the next step, I think the data will have to tell us what we need to do. And that’s the great thing about our rating scheme,” said Miller. “If we find data that supports a need to change or add our to our test protocol, we can do that, but we just we need the data and the science to back that up.

“Our primary mission is to inform the public on the relative difference in helmet performance. You know, just like anything else, there is big product differentiation—a Toyota Corolla is not the same as a Ford F-150 when it when it comes to safety, even though they’re tested the same, [and] they both have to pass that basic safety requirement,” Miller said. “But the beauty in what we do is the STAR [Summation of Tests for Analysis of Risk] rating system is designed to take all that really technical, high-end impact testing information and boil it down into a single rating.”

“Our goal is to capture the entire market; it just takes time and money to do it,” Rowson said. “We have a lot of parallel efforts in the lab. So if you look at our bicycle helmet ratings, we initially released with 30 helmets because we thought, OK, this is a good sample to at least give some information to the community.”

Now, after five or six years of testing, the lab has ratings for 271 bicycle helmets.

“We want people to understand the level of protection they currently have if they’re wearing a helmet, and then make an informed decision, if they’re interested, when purchasing a new helmet. So we try to capture everything. We don’t necessarily know what’s going to be good and what’s going to be bad. Sometimes the results are surprising,” Rowson said.