[Burphel]

Thanks largely to the NFL and NHL, concussions are starting to be taken seriously. Really up until the last 10 years or so, if you didn't wind up with a skull fracture or major brain damage, *everybody* figured the helmet had done it's job. Having a bell-ringer was just a sign that you survived something you probably wouldn't have without the helmet. Which is still true, but...

In the case of the NFL and NHL, (along with other contact sports), the forces generated *usually* don't actually generate enough force to cause fatal or crippling injuries anyway. So now they're kind of re-directing to tune the way their helmets are engineered to be better at preventing concussions since those happen pretty often, and we're starting to realize they have a bigger effect on people in the long term.

Coming back to motorcycle helmets, the forces we encounter in a wreck are still plenty enough to cause skull fractures and subdural hematoma. I'm gonna cite experience on this one, as I work as an ICU nurse and started out in Idaho, which doesn't have a helmet law. As far as current materials and engineering are concerned, they could re-tune for less G force during lower impact crashes vs a set G force with a higher speed impact (ECE vs Snell, as an example). But there's always going to be a trade-off unless you want to wear a gigantic helmet.

There's some interesting new developments being tried out, though. Mips, mostly used by Bell, helps cut rotational forces, without adding much weight or bulk. Klim just came out with Koroyd for their dirt helmets (using plastic tubes instead of foam) which should allow for multiple impacts and better tune-ability than foam. And, of course, they're getting lighter which means a bit less momentum for the head/helmet package.

Most of these are too expensive for a lot of riders, though. So we're stuck with choosing where we want to be on the "surviving one nasty impact vs being clear-headed after a smaller impact" continuum. For the time being, I'd still stick with the old-school advice to find something that fits good and is ECE or Snell certified. And wear the damn thing.