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The issue with helmet design is likely the same one football players face: that the place the impact absorbing material needs to go is between skull and brain.

The issue with helmet design is likely the same one football players face: that the place the impact absorbing material needs to go is between skull and brain. There’s no wearable helmet that’s going to change the result of skull being decelerated or accelerated as the brain keeps going. A strap or some padding that absorbs fleeting contact with the ice maybe has a chance to make a difference, but there are so few people involved in these sports that testing changes scientifically will be very hard.

CGamesPlay 6y ago
I'm no expert on helmet design, but surely you can absorb that force elsewhere, as long as the acceleration on the skull is damped? Degenerate case: a car's airbag does not go between my brain and my skull, yet it does prevent my brain from slamming into my skull.
- selectodude 6y ago
  No it doesn't, it prevents your skull from slamming into the steering wheel, lowering the forces inside your skull due to the longer time for deceleration is simply a side effect. Brain buckets are awesome for keeping your skull in one piece. Always have been.
  - Swizec 6y ago
    Wouldn’t the fact that your skull decelerates slower against an airbag than against a steering wheel mean that your brain hits your skull with less force?
    - elliottkember 6y ago
      Yes, that's what it does. It's not zero, but it's definitely less. But you probably only hit an airbag a couple of times max over the course of your lifetime, whereas on the field you'll hit your head the whole game. And I don't know how you could put an airbag in a helmet, there's not enough space to slow your impact
      - WalterBright 6y ago
        Make the helmet bigger, and put a liner filled with gel in it.
        tomcam 6y ago
        Not to be overprotective or anything, but after reading this I am just going to put my kids in giant rolling blocks of gel to keep them safe. Look for my YC Winter ‘21 startup GelBlok.io. If we need another compiler writer I will DM you
        WalterBright 6y ago
        Haha, my degree is in mechanical engineering. So I do know a thing or two about kinematics :-) The nice thing about gel is it squishes out of the way, and that squishing turns the spike into a more gradual push. It wouldn't take much gel to substantially reduce the spices. Of course, this would have to be tested. It shouldn't be too hard to test various designs.
      - modernerd 6y ago
        > I don't know how you could put an airbag in a helmet I own a Hövding, and they're supposedly six-to-eight times better than a traditional cycle helmet (particularly for neck stability): https://hovding.com/our-vision/ https://hovding.com/our-vision/ https://news.stanford.edu/2016/10/03/stanford-researchers-show-air-bag-bike-helmets-promise/ https://news.stanford.edu/2016/10/03/stanford-researchers-sh... Improvements to traditional helmets can definitely be made, although I'm not sure how practical an airbag helmet is for tobogganing, where it must also resist extended friction and multiple repeat impacts.
- paulcole 6y ago
  > a car's airbag does not go between my brain and my skull, yet it does prevent my brain from slamming into my skull No it doesn’t. The airbag stops your head. It doesn’t stop your brain.
WalterBright 6y ago
The integral of the force of time would be the same, but one can reduce the spikes in force. That's essentially what happens when a car is designed to crush, saving the occupants. The deceleration of the occupants is reduced and spread out over a longer period of time, but the total deceleration is the same.
fuzzythinker 6y ago
Yes there is, a one-piece helmet-torso design that allows neck flexibility [1] - this is dated 2012, but I remember reading about it even before 2000. Think it will work much better for sled than American football since there should be much less sudden neck movements. [1] https://cerebrovortex.com/2012/10/04/the-v2-prototype-football-helmet-and-neck-torso-one-piece-attachment-coined-the-h-a-n-t-device-invented-by-dr-todd-aaron/ https://cerebrovortex.com/2012/10/04/the-v2-prototype-footba...

CGamesPlay 6y ago

I'm no expert on helmet design, but surely you can absorb that force elsewhere, as long as the acceleration on the skull is damped? Degenerate case: a car's airbag does not go between my brain and my skull, yet it does prevent my brain from slamming into my skull.

selectodude 6y ago
No it doesn't, it prevents your skull from slamming into the steering wheel, lowering the forces inside your skull due to the longer time for deceleration is simply a side effect. Brain buckets are awesome for keeping your skull in one piece. Always have been.
- Swizec 6y ago
  Wouldn’t the fact that your skull decelerates slower against an airbag than against a steering wheel mean that your brain hits your skull with less force?
  - elliottkember 6y ago
    Yes, that's what it does. It's not zero, but it's definitely less. But you probably only hit an airbag a couple of times max over the course of your lifetime, whereas on the field you'll hit your head the whole game. And I don't know how you could put an airbag in a helmet, there's not enough space to slow your impact
    - WalterBright 6y ago
      Make the helmet bigger, and put a liner filled with gel in it.
      - tomcam 6y ago
        Not to be overprotective or anything, but after reading this I am just going to put my kids in giant rolling blocks of gel to keep them safe. Look for my YC Winter ‘21 startup GelBlok.io. If we need another compiler writer I will DM you
        WalterBright 6y ago
        Haha, my degree is in mechanical engineering. So I do know a thing or two about kinematics :-) The nice thing about gel is it squishes out of the way, and that squishing turns the spike into a more gradual push. It wouldn't take much gel to substantially reduce the spices. Of course, this would have to be tested. It shouldn't be too hard to test various designs.
    - modernerd 6y ago
      > I don't know how you could put an airbag in a helmet I own a Hövding, and they're supposedly six-to-eight times better than a traditional cycle helmet (particularly for neck stability): https://hovding.com/our-vision/ https://hovding.com/our-vision/ https://news.stanford.edu/2016/10/03/stanford-researchers-show-air-bag-bike-helmets-promise/ https://news.stanford.edu/2016/10/03/stanford-researchers-sh... Improvements to traditional helmets can definitely be made, although I'm not sure how practical an airbag helmet is for tobogganing, where it must also resist extended friction and multiple repeat impacts.
paulcole 6y ago
> a car's airbag does not go between my brain and my skull, yet it does prevent my brain from slamming into my skull No it doesn’t. The airbag stops your head. It doesn’t stop your brain.

WalterBright 6y ago

The integral of the force of time would be the same, but one can reduce the spikes in force. That's essentially what happens when a car is designed to crush, saving the occupants. The deceleration of the occupants is reduced and spread out over a longer period of time, but the total deceleration is the same.

fuzzythinker 6y ago

Yes there is, a one-piece helmet-torso design that allows neck flexibility [1] - this is dated 2012, but I remember reading about it even before 2000. Think it will work much better for sled than American football since there should be much less sudden neck movements. [1] https://cerebrovortex.com/2012/10/04/the-v2-prototype-football-helmet-and-neck-torso-one-piece-attachment-coined-the-h-a-n-t-device-invented-by-dr-todd-aaron/ https://cerebrovortex.com/2012/10/04/the-v2-prototype-footba...