Originally Posted by
JohnJ80
Protection. That's the whole purpose behind wearing a helmet. You wouldn't wear one otherwise.
Broad brush - two kinds of head injuries: penetrating/points hits (i.e. you fall and your head hits a rock) and diffuse axonal injuries (i.e. shearing of neurons - "Shaken Baby Syndrome"). Virtually all helmets protect largely the same on the first kind due to statutory standards in place. The second kind (and maybe the overall worst to recover from) is just now being addressed with new technology in helmets. The most prevalent of these technologies is MIPS (
http://mipshelment.com). You can find this technology in POC, Scott and a few others. MIPS protects from an obtuse hit the head that causes the rotational acceleration on the brain that causes the shearing.
Having lived through a serious sports related TBI with a family member, we researched this heavily.
This excellent article from Bicycling magazine explains it very well from a cycling perspective.
Maybe you can fill in some blanks for me on MIPS then; I'm having trouble finding more than reference articles talking about it and the pretty videos, but not quite enough on what it does. I get the concept, the low friction interior allows for shift, replicating the way things happen inside your skull. The info in the videos looks like it does an excellent job for motorcycle and other tight fitting helmets.
What doesn't make as much sense to me is how it works in a helmet which already is a bit looser. I can't find any information on that. Something sitting on top of your head with just one strap, even pulled tightly, is going to have more movement than I've seen represented so far. So is it benefiting in this scenario? Do the helmets with MIPS by Scott and the like simply have the patented design included, or do they have additional tests for these configurations? If anyone has a link that covers this, I'd love to see it. If the low friction layer is allowing for rotation to absorb some impact, that would only work if the inner layer is secure enough that the impact force would move the outer layer but not the inner layer; otherwise, it does nothing.
I'm all for safety, my brain is what pays the bills after all, but I just want to make sure what I'm paying for is founded in practical use, not pure theoretical that wouldn't match what would happen on the road. Which is what annoys me about some other certifications out there.