Virginia Tech's STAR helmet ratings
This month, Safety Corner presents a guest article by Randy Swart, the leading independent expert on bicycle helmets. He discusses the rating system for bicycle helmets recently launched by Virginia Tech University, a development which came to my attention through a message on the CRW e-mail list. The article also appeared on Randy's Web site, helmets.org, which includes lots of other useful information -- and is reproduced here with his permission -- John Allen
Virginia Tech's STAR helmet ratings
Summary: Virginia Tech University has developed a methodology for testing helmets for their ability to reduce concussions. After football and hockey helmets, they launched ratings for bicycle helmets in June of 2018. We have some reservations about their testing, but support the concept of trying to rank helmets for low-level impact performance. We have a page listing helmet models where the STAR ratings and Consumer Reports ratings concur.
Virginia Tech's Biomechanical Engineering department has been involved in concussion research in football for a number of years, outfitting teams with sensors to detect concussion-level hits and developing a very large database of hits and diagnoses. They developed a program called STAR ratings based on that research, rating football helmets on their ability to prevent concussions. Although there is no agreement among helmet and concussion experts that the ratings are based on exact concussion parameters, we think they represent a valid attempt to use lab testing to highlight concussion-level performance. After football, Virginia Tech took on hockey helmets. Now in 2018 they have developed a program to rate bicycle helmets. It is headed up by Megan Bland, a Graduate Research Assistant and PhD Candidate at the Virginia Tech Helmet Lab in their Department of Biomedical Engineering and Mechanics. She is working with Dr. Steven Rowson and Craig McNally, and the methodology is similar to the football and hockey helmet programs. Their STAR ratings page has all the details. Here is a video of the test methods that summarizes the testing.
Standards development has lagged far behind the increased concern with concussion-level impacts. The science of concussions is still developing, and standards-makers are reluctant to introduce new benchmarks until the exact anatomical parameters are clear. The resultant helmets might not be any better than today's. The Virginia Tech approach is an attempt to use field data to get close enough to concussion causality to rate helmets on their ability to perform in the range of impacts that lead to concussions. For that reason, we consider their program an important advance in helmet testing. The bicycle-helmet impact tests evaluated a helmet's ability to reduce linear acceleration and rotational velocity of the head from a range of impacts a cyclist might experience. The risk formula identifies helmets that may provide a reduction in concussion risk for these impacts compared to helmets with fewer stars. There are four at the top: Bontrager Ballista MIPS, Louis Garneau Raid MIPS, Bell Stratus MIPS and Specialized Chamonix MIPS. At the bottom are the Lazer Genesis and Bern Watts, with only two stars. You can access the most current version of the ratings on the Virginia Tech site.
Limitations and caveats
We are excited by the release of the first bicycle helmet STAR ratings. But we recognize some limitations of the Virginia Tech program. Only 30 models were rated in the initial testing. Ten were MIPS models. They were tested using the methodology that MIPS uses: sticky headform, tight strap, severe anvil angle, rough grippy anvil, no neck. That methodology couples the headform more tightly to the helmet than it would be in the real world. It would be expected to favor the MIPS models, unlike the Snell Foundation's research that showed no benefit from MIPS.
There is still no consensus that the Virginia Tech formula for rating helmets for concussion pinpoints the helmets that reduce concussion the best. Changes to the tested helmets to improve their scores might not result in fewer concussions in the field. But since established standards organizations have failed to respond to concussion concerns, these ratings represent a good start at testing helmets systematically for lower-level and rotational-impact performance.
In addition, the Virginia Tech testing uses only medium-sized helmets at ambient lab conditions. Normal standards testing uses more helmets, more impact locations, and tests helmets that are cold, hot and wet. It is difficult to see how Virginia Tech drew general conclusions about the value of MIPS and about urban (skate-style) helmets needing improvement based only on their limited testing.
We think consumers should take note of the STAR rankings, but use them as one decision-making factor in their buying decisions. Avoiding a concussion is important, but not as important as knowing how your helmet performs in more severe impacts that can kill. There is no program that addresses that except the few helmets that Consumer Reports tests. We look for further development of the effort by Virginia Tech and others, and hope that thes will pressure traditional standards-making organizations to move forward with similar testing. We have a page listing helmet models where the STAR ratings and Consumer Reports ratings concur.
Some additional perspective
Here is a presentation that BHSI's Randy Swart did for the International Conference on Safety in Cycling in 2017. It outlines our hopes for the rating systems being developed by Virginia Tech and other universities in the UK, Europe and Australia.
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