I was at the Interbike tradeshow for the bike industry this past September and learned about a new bike helmet technology that reduces the force of common low speed impacts. With all of the recent news about how concussions and even sub-concussive level forces can impact brain function, I thought this might be worth sharing for all of you that ride bikes or have kids that ride bikes.
Both of my kids play club soccer and it's been REALLY eye-opening about how long kids with concussions are now required to abstain from activities posing potential risk of additional head impacts after an initial concussion. One of my son's soccer teammates sat out from playing after receiving a concussion for about 5 months on doctor's orders. What's particularly concerning to me is that repeated impacts of even a sub-concussive level may have long-term health effects (though the science on this is far from settled). One example of a study that came up with evidence of this was a study that found functional cognitive impairment in high school football players that had not experienced clinically-diagnosed concussions: https://www.ncbi.nlm.nih.gov/pubmed/20883154. In this study, researcher found that the players with the most impaired visual memory skills were actually not those that had experienced concussions but rather the players which, in the preceding week, had experienced a large number of subconcussive hits - around 150 hits - mostly in the 40 to 80 g range. The Purdue researchers suspect that these players experienced neurological trauma arising from repeated, sub-concussive head collision events, each of which likely produces sub-clinical stress on neural tissue in the brain.
Existing bicycle helmet crash tests focus mainly on reducing the risk of skull fractures from high speed impacts, but increasing the density of helmet foams to reduce the risk of skull fractures in higher speed crashes actually reduces effectiveness at reducing forces from lower speed crashes. The density of bike helmet foam necessary to meet current crash standards is more firm than ideal to adequately absorb the impact from lower speed crashes at a level that would cause concussions. Adding a softer helmet layer to existing bike helmet designs would be one way tohelp slow down the acceleration of the head in these lower speed crashes.
One of the new technologies that I was really excited to find at the Interbike bike industry trade show this past September was 6D Helmets' Omni-Directional Suspension (ODS) technology that helps reduce forces transmitted in low speed impacts. 6D's technology adds a layer of rubber bumpers between two foam layers to reduce impact speed and force (see attached picture). The NFL chose 6D and its ODS technology to beone of 5 finalists chosen out of 125 entries in the NFL's Head Health Challenge III (https://ninesights.ninesigma.com/web/head-health/challenge-3-winners) to discover, design & develop advanced materials that better absorb or dissipate impact. I was so impressed that I got a 6D bike helmet for myself and will get them for my family as well.
If you're interested in more details, I've posted a video of Bob Weber, co-founder of 6D Helmets, talking about how their technology works. It's located at: https://www.dirtmerchantbikes.com/special-events/2016/10/4/interbike-2016-video-6d-helmets-reduction-of-concussion-level-forces-in-bike-crashes