Breaking Down Virginia Tech's Helmet Ratings

What are the Virginia Tech Helmet Ratings? And why should you care as a helmet consumer? The short answer is the reduction of concussion risk. Since 2011, Virginia Tech has been testing helmets in sport-specific conditions. Some helmet manufacturers are using these test results to drive innovations in helmet design and materials. I met with Dr. Barry Miller to learn more about how cycling helmets earn the STAR ratings they do and to ask if innovations like MIPS make a difference in the test results. Below are the major take aways from our conversation.

Helmet Testing

By law, all bicycle helmets sold in the US must be certified by the Consumer Product Safety Commission (CPSC). If you look inside your helmet, you will find a sticker (if it hasn’t become detached with use) that attests to this certification. The CPSC testing is pass/fail and involves four tests, one of which is a drop test. The pass/fail threshold for the drop test is the point of skull fracture. As helmet consumers, all we know from the CPSC certification is that our helmet passed the minimum standard to be sold to us in the US and will hopefully prevent a skull fracture. However, we don’t know from the CPSC certification the extent to which any particular helmet reduces concussion risk.

That’s where the Virginia Tech Lab comes in with much more involved and rigorous helmet testing. For each sport addressed by the lab, Barry’s colleagues developed a specific test protocol based on field observations. For football, the field testing involved collecting data from sensors within the helmet during practices and games. For cycling, the field testing involved simulation studies of bicycle accidents.

The helmet testing protocol and evaluation system that the lab developed for cycling is detailed in an open access, peer-reviewed journal article (Bland, et al., 2020), but here are the highlights:

Helmets are tested on a custom drop tower that involves dropping a helmeted headform on to a 45-degree steel anvil covered in sand paper. The angle of impact was determined from simulation studies, and the 80 grit sand paper simulates road friction. The helmet is dropped on six locations on the helmets at two velocities to simulate low-speed and high-speed impacts. The low-speed impact is the most common in cycling, while the high-speed impact is meant to represent the types of impacts that most commonly result in concussions.

In short, for a helmet to do well in the Virginia Tech lab, it must be dense enough to pass the high energy CPSC impact test to prevent skull fractures and compliant enough to reduce concussion risk based on linear and rotational forces that are measured at two velocities.

This data then gets weighted based on frequency in real-world impact scenarios and run through a formula detailed in the article that takes into consideration concussion injury risk. The result of the calculation is the Summation of Tests for the Analysis of Risk (STAR) score. While the calculation of the data is hard to follow, the STAR score is easy to understand. The lower the STAR score, the lower the concussion risk when wearing the helmet while cycling.

What’s my helmet rated?

Your helmet may or may not be currently included in the Virginia Tech bicycle helmet ratings. Barry said that helmets come to the lab in a variety of ways. Manufacturers will send their prototypes and commercially available helmets to the lab for testing. Some of these manufacturers, like LAZER for example, will report the STAR ratings for their helmets as a selling point. The lab will also occasionally buy helmets on the open market if there is high demand for a particular helmet from consumers or if a helmet is featured by other helmet testers, such as Consumer Reports. The lab attempts to test a variety of brands, design technologies, and price points.

If your helmet is listed in the ratings, take note of the STAR score in the low impact energy compared to the high impact. Again, the lower the score the lower the risk of a concussion when wearing that helmet properly.

The Price of Safety

If we believe all the marketing hype, we might assume that a more expensive helmet might be safer. But, that’s not necessarily the case based on the sample of helmets tested by the Virginia Tech Helmet Lab within the road category.

Of the top 30 road helmets (ranked overall 1 through 65), the STAR scores ranged from 8.40 to 11.28 (all five stars). Fourteen are $250 and above, thirteen are between $100 and $250, and three are less than $100. Of particular note, the Giant Rev Comp MIPS has a STAR score of 9.13 and a cost of $65.

Barry shared that the reason for why a helmet does better than another in the testing is varied and heavily based on the design of the helmet. He said that the materials themselves are relatively inexpensive so that a $65 helmet from Giant with a generous amount of EPS foam can outperform a more expensive helmet with a different design.

What about MIPS?

I asked Barry about the significance of MIPS for reducing concussion risk. Sixteen of the top 30 road helmets in their ratings have MIPS installed.

Barry shared that MIPS helps the helmet decouple from the head upon impact. Ideally, the helmet will be in the correct position on your head during a crash, but the helmet will also shift a bit on impact absorbing some of the energy that your head experiences. MIPS performs well in the STAR ratings, in part because the headform used in the tests does not have hair. MIPS acts as a slip plane between the head and the helmet facilitating the decoupling upon impact.

However, Barry said that MIPS won’t help in all crash situations. In particular, MIPS is not going to help absorb linear impacts. But in the case of severe oblique impacts, MIPS may enhance how the helmet decouples. The big question for Barry is whether MIPS helps when you have a full head of hair. He said it greatly depends on the location, the angle, and the amount of energy of the impact, with most of the protection coming from the density and thickness of the helmet.

In sum, MIPS may help the helmet decouple in certain situations, but the presence of MIPS is only one factor among many that determine the amount of risk of concussion.

Helmets continue to improve

The good news is that helmets keep getting better. Barry is excited about the potential of new helmet design technologies like WaveCel, Omni-Directional Suspension, honeycomb structures like HexaGo and KAV, and Koroyd.

Barry said that as the helmets continue to improve, the Virginia Tech Helmet Lab will need to adjust their thresholds for their STAR ratings. Currently, a five-star helmet has a STAR score under 14. Barry foresees a time when they will need to reduce the five-star rating to a STAR score of 10. Currently, only nine road helmets rated by the lab have a STAR score under 10.

Large volume hair

I asked Barry if there were any promising helmet designs that accommodate large volume hair. There are very few helmets on the market that do so effectively, and my colleagues and I, who work with Black and Brown youth in Dr. Noemi Waight's STEMCyclists program at the University at Buffalo (SUNY), are always on the lookout for viable helmet designs. Barry shared that there are some viable designs used in other sports that could be used in cycling. One example is a helmet with an adjustable shell used in hockey that could be used to better accommodate large volume hair. He shared that a student group from Northwestern University was visiting the lab working on helmet designs for large volume hair that will hopefully test well in the lab. However, Barry cited market demand as the largest obstacle to incentivize manufacturers to bring viable designs for large volume hair to diverse consumers. Safety and reducing concussion risk are yet more reasons to advocate for diverse participation and representation in cycling.

Exposure to Risk

The more risk of concussion that you are exposed to, the more these helmet ratings may matter to you. In competition, a criterium racer is arguably exposed to more concussion risk than a triathlete. But in training on open roads in car traffic, those concussion risks may be more similar. A bike commuter may be exposed to even greater risk than both of those athletes and want a larger, more protective helmet. The Virginia Tech Helmet Testing Lab recommends any of their five or four star helmets. However, when you are weighing cost versus benefit at the point of helmet sale, you may want to take into consideration the STAR score if it’s available for the helmets you are considering. And if the helmet isn’t listed, don’t hesitate to contact the lab and suggest that the helmet be added to their testing cue.