11 ms·

I’m going to comment with what seems to be the common sentiment here. It’s really hard to tell how effective a helmet is at preventing concussions in real life

by parsimo2010 7y ago

I’m going to comment with what seems to be the common sentiment here. It’s really hard to tell how effective a helmet is at preventing concussions in real life. So we/they design a test of some hypothetical concussion cause, and lo and behold, their helmet is very effective in that test. Note that this is a different test than the ones used to prove that MIPS was better than a styrofoam helmet. The real story is that marketing probably has a bigger influence than science in this case. Several years ago helmet manufacturers hit the practical weight limit for helmets with styrofoam and carbon fiber shells. I bought a Giro Atmos over a decade ago and never needed to upgrade because the top of the line helmets were only a couple grams lighter, after a decade of “improvement.” The manufacturers noticed that helmet sales were declining, and all of a sudden “new science” appeared with a theory about concussions being caused by brain rotation and MIPS technology helps prevent that. How convenient that this appeared. The dirty secret is that literally nobody has ever seen a brain rotate inside a skull and result in concussion. It’s really hard to image a brain in motion (impossible with off the shelf equipment), so the brain rotation theory is just a hypothetical mechanism. There isn’t an ethical test for blunt force trauma in real life conditions, and bike crashes are very rarely reported if they don’t send the rider to the hospital. So the leading authority on product safety, the Consumer Product Safety Commission, doesn’t even have good numbers on concussion rates for cyclists. The bottom line is that MIPS and this new gel layer came at way too good of a time for the helmet industry for us not to be wary of the science. They can get away with it because it’s such an easy marketing sell- most people think their life is worth more than $250, so any helmet tech is a bet on the order of Pascal’s wager. If it’s snake oil I’m just out $250, but if it really is better then I just saved my life in a crash.

duxup 7y ago
I recall an American football study looking for concussion symptoms and impairment. They found people with a history of repeated concussions, and then as what they thought might be a group to compare to some American football linemen with no history of concussions to compare with. They found linemen with the same issues despite no concussion history. This raised the possibility that worrying about severe hits that result in a concussion was possibly missing a larger issue. It seems our understanding of brain injury and even how it comes about may be inaccurate.
- javagram 7y ago
  American football involves constant collisions. That type of research suggests that even without a “concussion” the same type of damage can occur from repeated, more mild collisions. Cycling seems like a different order entirely, it’s extremely unusual for a cyclist’s head to hit anything and only happens during an accident or mishap.
  - JauntyHatAngle 7y ago
    Soccer is a good example. You are rarely concussed from heading a soccer ball, but there is some evidence that players may suffer brain damage from from repeatedly heading the ball. https://www.sciencedaily.com/releases/2018/04/180424112923.htm https://www.sciencedaily.com/releases/2018/04/180424112923.h...
    - scarejunba 7y ago
      45 headers in two weeks were enough. Holy Jesus! Thank you for bringing this to my attention. I probably won't heal but maybe I'll protect from damage.
- mabbo 7y ago
  > They found linemen with the same issues despite no concussion history. With no reported concussion history.
  - grogenaut 7y ago
    Reported can mean many things. If I was asked in such a study I would bring up the 7 our situations I know of where I even suspected I might have had a concussion, mostly snowboarding related actually (with helmet), odd given I also played 9 years of football and 9 of Aussie rules. None of them with concussion effects other than maybe I'm done for the day (you tend to take bigger falls when you are tired). Also seen enough concussions and evaluations to be able to identify those exhibiting obvious symptoms tho I'm not trained in it. I would let the people running the study decide how to classify them. Its also not like there is a standard "reporting" form for concussions. Especially further back and esp if you had a team doctor.
Alex3917 7y ago
> They can get away with it because it’s such an easy marketing sell- most people think their life is worth more than $250, so any helmet tech is a bet on the order of Pascal’s wager. I think this is basically accurate. Even if you have zero expectation that either this or MIPS or whatever works, I don't see how anyone who has seen Crash Reel or any of the football-related concussion documentaries could possibly not spring the extra few bucks. Someone should put together a list of the cheapest or highest expected-value Pascal's wagers. Even things like flossing your teeth are a good example, where it's clearly good for your gum health even though the Cochrane research is equivocal. (Although using a WaterPik is probably better, especially if you do so in addition to flossing.) Anyway if you haven't seen it, this movie will change the way you think about sports: https://www.youtube.com/watch?v=c1hxtjlbTHI https://www.youtube.com/watch?v=c1hxtjlbTHI
- stbtrax 7y ago
  If you have long hair, MIPS will eat it and not let it go. I don't get how MIPS is different from just wearing a cycling cap
  - entee 7y ago
    MIPS (you seem to know this, but many might not) is an internal layer in the helmet, usually a very thin rigid plastic layer, that has some elastic nubbins/supports between it and the outer helmet styrofoam shell. This means that the inner shell is free to stay put while the outer styrofoam shell rotates. This would be different than a cap in that the elastic nubbins should dissipate some of the energy. All this is a bit speculative, but that's what I'd go with.
- deleted 7y ago
  [deleted]
- frabbit 7y ago
  Interesting take-away from having watched football-related concussion documentaries. For a long period of time football players were told that if they wore helmets they were protecting their head. So they were lured into dangerous behaviors. If cycling is a dangerous as playing football (it's not) then bicycle helmets would fulfill the same misleading role as football helmets. As it is cycling is relatively safe and helmets are observed to make no measurable difference in outcomes[1] 1. https://www.badscience.net/2013/12/bicycle-helmets-and-the-law-a-perfect-teaching-case-for-epidemiology/ https://www.badscience.net/2013/12/bicycle-helmets-and-the-l...
jpmattia 7y ago
> most people think their life is worth more than $250 FYI, I just bought the Bontrager wavecell last weekend for $150 at REI. It was a no-brainer, so to speak. [I just had the worst crash of my life 2 weeks ago. I incurred nothing worse than scrapes and bruises, mostly because the helmet did its job, but needed to replace it after the crash.]
- iamnotacrook 7y ago
  If the helmet wasn't damaged in the crash it meant the energy was harmlessly transferred into your head. You want the helmet to be damaged/destroyed.
  - entee 7y ago
    It's often not clear whether the energy went into the helmet. It could have cracked something internally or substantially weakened the EPS under the plastic shell without it being super visible. Better to not risk it: serious crash, replace helmet.
  - jpmattia 7y ago
    If you didn't know better, it looked like someone hit the helmet with a hammer a couple of times. So yes, some amount of kinetic energy was dissipated in deformation of the plastic rather than my skull. I was more than a little grateful.
  - dahart 7y ago
    > If the helmet wasn't damaged in the crash it meant the energy was harmlessly transferred into your head. Foam can and does distribute and absorb shock without being significantly damaged or destroyed in less severe collisions, crashes that can still put you in the hospital without a helmet. I would maybe describe how helmets work as having a shock-absorbing cushion that slows deceleration of it’s contents. Talking about “energy” is bound to be misleading or confusing, since from a given speed, you always transfer the same amount of energy no matter how you stop, whether it’s a sudden strike against concrete or a slow gentle braking, or even waiting several minutes for air and tire friction to wear out all your kinetic energy. I don’t want the helmet to be damaged or destroyed only because that means the crash is bad or severe.
hevi_jos 7y ago
>The dirty secret is that literally nobody has ever seen a brain rotate inside a skull and result in concussion. Are you sure?. We have a thing called tomography with things like xrays, magnetic resonance that let's us look inside bodies. Experiments were done in the past with animals that have a similar brain to us, specially aviation military, that were extremely interested on concussions. At least they have x-rays photography of impacts. By the way all this research led to car's seatbelts. Thousands of brain surgical procedures are done each year, there are experts in the anatomical features of the brain, and we have detailed maps of sliced brains and complete heads. Tens of thousands of people die in car accidents and hundred of thousands are injured. Insurance companies have extensive documentation on those. We know the physical properties of those things and we have things called computers that let us do very complex models about the brain with finite elements or just analog 3d printed models with gelatin and plastics. To say that nobody can imagine a brain in motion, so everything is a hypothetical mechanism is quite unfortunate. We know a lot about what happens more or less. Things have improved dramatically for people like motorbike racers because we actually know a lot and lots of lives had been saved because of that.
- parsimo2010 7y ago
  Literally all those things you mentioned happen in static environments. Note that I said we can’t image a brain in motion, all we have for that are computer models. Sure, they’re plausible, but we can’t even agree on what crashing forces applied to the cranium look like, let alone the resultant brain movement and pressures induced. You can’t CT a brain as the head is falling. Nobody has ever drilled holes in someone’s skull and mounted pressure transducers inside the skull to truly validate the pressures during impact. All the “validation” has happened in lower fidelity domains (particularly the time domain), this is a bit like claiming that you know calculus because you can do addition really good. Every mechanical engineering student will tell you that dynamics is a different beast than statics. Fancy computer images does not the truth make. Note that I’m not saying that a MIPS or WaveCel helmet is worse than the previous generation, I’m just pointing out that the timing in which these features appeared on the market is suspect, which causes me to suspect the “science” behind it. It is most likely that these antirotation features don’t make the helmets worse but also not any better.
sliken 7y ago
I agree. I've raced on road, off road, been a bicycle messenger, and commuted on bike to work every working day since 1994. Accidents happen and helmets help. The most dangerous thing about a bike accident is generally the vertical distance. Try laying down on concrete, lift your head up an inch, and drop it. Keep in mind that when falling your acceleration is 9.8 m/sec/sec, so a 10 inch fall is worse than 10 times as bad as one inch. The MIPS and Wavecell seem to assume that helmets grab the road with great traction and then snap your skull producing a large rotational acceleration so great that your brain falls behind. In my experience helmets (which are at first approximation spherical) hit in the center, easily skid, and induce approximately zero rotation in your skull. I do recall in the 1990s or so that as brands switched from a heavier plastic shell (like the ancient bell helmets) to the then common nylon sleeve over the styrofoam that one manufacturer picked a particularly high friction material which did cause additional injuries. Once that was fixed everyone was happy again. So absorbing energy from the fall is great. Playing games with additional layers with low internal friction or fancy ways to collapse is useless. I'm not completely against the idea, but seems laughable to pay 3-6X for something unlikely to help. Bike helmets that meet the toughest impact standards are available for $50 or so. I personally have fallen many times, had my helmet skip many times (the longest was more than 10 feet) and never noticed my helmet gripping the ground and trying to torque my head.
- tzs 7y ago
  > Keep in mind that when falling your acceleration is 9.8 m/sec/sec, so a 10 inch fall is worse than 10 times as bad as one inch. Shouldn't that be sqrt(10) times as bad? The distance fallen under constant acceleration g for t seconds is 1/2 g t^2, so it takes sqrt(10) times as long to fall 10 times as far. The velocity after falling t seconds is g t, so falling sqrt(10) times as long gives a velocity of sqrt(10) times as much.
  - sliken 7y ago
    Ha, sorry, yes. I confused 10 times as long with 10 times as far... I should have double checked the math. Still dropping your head an inch (painful) is a nice reminder of how much energy is involved from normal riding height.
olooney 7y ago
why not use an animal model?
- jpmattia 7y ago
  How cruel.
  - ipsum2 7y ago
    Cancers are regularly induced in mice and rats. Almost every single medicine has been tested on animals before they're used on humans. Modern medicine is built on animal models. It's unfortunate, but a sufficient tradeoff a vast majority of people are willing to make.
    - jpmattia 7y ago
      I’m not entirely sure what you are saying. Is it not cruel, or that the cruelty is OK?
      - Biganon 7y ago
        They're saying it's cruel, but some cruelty is sometimes needed if the benefits for humanity are worth it.
- parsimo2010 7y ago
  Because diagnosing an animal concussion is harder than diagnosing a human concussion. Animals can’t tell you if they have a headache, light sensitivity, nausea, etc. You would only be able to diagnose the worst class 3 concussions where the animal can’t even walk straight. It’s probably not ethical to subject animals to that much pain if you can’t even confirm half of the injuries.
  - adrianN 7y ago
    Aren't concussions visible in MRI?
ramy_d 7y ago
My understanding of MIPS was that it was meant to redirect linear force against the head, such as banging your head against a car in a relatively straight line, into a rotational force that would let the helmet slip off the head and that would reduce the amount of trauma to the skull. I never heard of anything about "brain rotation"
- parsimo2010 7y ago
  This explanation of MIPS goes pretty much all-in on it being about rotation: https://www.torpedo7.co.nz/community/help-and-advice/bike/gear-advice-technical-info/3604 https://www.torpedo7.co.nz/community/help-and-advice/bike/ge... Edit if you prefer it directly from the marketing horse’s mouth: https://mipsprotection.com/ https://mipsprotection.com/
  - ramy_d 7y ago
    When you have suffered a concussion or an even more serious damage to the brain, rotational motion to the brain is the most likely cause. from the mips protection website, you are correct and i understood it upon first reading as something else
    - taneq 7y ago
      Wow, given that they're talking about something that invariably has a significant linear acceleration factor, that's a pretty... confident... way to put it.
zachrose 7y ago
> I bought a Giro Atmos over a decade ago and never needed to upgrade... I’m sure you’ve heard this but they say to replace a helmet every two-three years even if it hasn’t been in a crash. It’s up to you whether you think that makes sense, but I’d sooner believe it than not.
- TheSpiceIsLife 7y ago
  It'd be hard to miss the potential for that to be marketing-speak for "buy more helmets more often", especially given the context of the comment you replied to.
  - adrianN 7y ago
    I've had old helmets develop cracks spontaneously so this is marketing that I tend to believe.
    - TheSpiceIsLife 7y ago
      By old do you mean two years or twenty?
      - adrianN 7y ago
        I think that helmet was less than four years old. And it wasn't a cheap one either.
        jacquesm 7y ago
        That's a warranty issue more than a reason to buy another one of the same brand.
- Cyclone_ 7y ago
  I've raced for about 6 years now and have not replaced my tri helmet, but have replaced the one I use when I'm on my road bike (only because it broke in a crash), where did you hear that you should replace the helmet that frequently?
petre 7y ago
I believe all the current Giro helmets are MIPS now, even the cheap ones. In fact I was contemplating of getting one myself, not necessarily because of MIPS but if it's safer and also looks good, cool.
taneq 7y ago
> The manufacturers noticed that helmet sales were declining, and all of a sudden “new science” appeared with a theory about concussions being caused by brain rotation and MIPS technology helps prevent that. > There isn’t an ethical test for blunt force trauma in real life conditions, and bike crashes are very rarely reported if they don’t send the rider to the hospital. There's one ethical source of data - televised bike races. Surely there are enough crashes recorded in publicly accessible videos to provide a fairly representative sample of how a human head moves when the helmet it's wearing hits the road. > They can get away with it because it’s such an easy marketing sell- most people think their life is worth more than $250, so any helmet tech is a bet on the order of Pascal’s wager. It's exactly the same with motorcycle helmets. You can get a DOT approved helmet for $150, but the general perception in the community is "if you have a $150 head, wear a $150 helmet". Then everyone pays $800 for helmets designed to European standards which are meant for racing, and give dubious benefit if any at normal road-going speeds (eg. see https://www.nytimes.com/2009/09/27/automobiles/27SNELL.html https://www.nytimes.com/2009/09/27/automobiles/27SNELL.html).
- nradov 7y ago
  Most of the crashes I've seen in televised pro races were shot from only a single angle some distance away, and often with obstructed sight lines. So I'm skeptical that those videos will give us useful data on head movement.
  - piquadrat 7y ago
    Also, pros crash differently than your typical bike commuter or recreational cyclist. For one, there's a large difference in speed (45+ kph for pros, half of that or less for your typical commuter - somewhat negated by the e-bike boom). Next, pros in televised races don't have to deal with oncoming traffic, so head-on collisions are a non-factor. And lastly, pros know how to crash (tuck in, roll over, dissipate energy over a distance), while non-pros tend to tense up in a crash situation. There's probably other ways in which pros crash differently, making them a less than ideal sample of the overall cycling population.
    - 7y ago
kmonsen 7y ago
Just a quick tip, bike helmets actually have expiration dates and should be replaced every 3-8 years depending on the helmet.
xorcist 7y ago
Wearing a helmet is always better than no helmet. Any helmet. That doesn't mean the technology can't be improved, and there's actual science being done. Brains are being imaged. There are peer reviewed articles published every year that details the challenges of how to model brain damages. It's not fair to brush them off as just an invention in marketing. So far it does seem that measuring impacts at an angle matches real world brain damages better than the older standards of measuring dead-on impacts. That's what "rotational acceleration" means. Acceleration is just another word for impact. It doesn't mean your skull should rotate freely. There are enough indications that this translates to helmet improvements that most consumer organizations have started to recommend them should you buy a new one. That doesn't mean you should throw away your old helmet but it should be enough to disqualify it as "snake oil". This new Wavecel system hasn't been reproduced yet, two testing institutes has so far failed, but it is similar enough to existing cell and slip systems that performance is not likely to be worse.
- jchanimal 7y ago
  I hope you wear a helmet in the shower and when you drive a car.
  - henryaj 7y ago
    How often do you hit your head at 30mph in the shower? Doesn't your car have seatbelts and airbags?
    - sporkland 7y ago
      If you're doing 30mph on your bike you're doing a different type of biking than me and most commuters.
      - massaman_yams 7y ago
        I use the same helmet when commuting and on longer/faster rides.
    - 7y ago
pisteoff 7y ago
Blah blah blah. While I appreciate the skepticism, this is BS only for the sake of it (as so many HN comments are). You instantly lose credibility with this line: "I bought a Giro Atmos over a decade ago and never needed to upgrade because the top of the line helmets were only a couple grams lighter, after a decade of “improvement.” I hope you've since replaced it. General guidelines are to replace a helmet every three years due to material degradation and UV damage. Yes, you are correct that there is a marketing element. Likewise, you are correct that people value their lives over $250 price tag. As a bit of antidotal evidence, I had a fall this weekend on Evolution trail on Galbraith MTN in Bellingham, WA. I fell from about 6-7 feet up on a feature called the Stinger, a long, super fun north shore style bridge (watch some youtube videos if you want to see it). My face and head were impacted in the fall and I suffered, what I think is, a very mild concussion. I replaced my helmet afterwards as per the recommendations. I also have a history of TBI caused by a cycling accident where wearing a helmet saved my life. I am absolutely going to buy something that even vaguely suggests an advantage for injury prevention. Mountain Biking is, after all, and inherently dangerous sport. As you suggest, any progress is good progress when it comes to saving lives. But I absolutely disagree that it "is a bet on the order of Pascals wager," especially when it seems I myself have made that wager and come out ahead. So, with the utmost respect, unless you are a leading researcher in this field, STFU.
- dwohnitmok 7y ago
  This reply doesn't seem to be in line with HN guidelines. "Be kind. Don't be snarky." and "When disagreeing, please reply to the argument instead of calling names. 'That is idiotic; 1 + 1 is 2, not 3' can be shortened to '1 + 1 is 2, not 3.'" https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

duxup 7y ago

I recall an American football study looking for concussion symptoms and impairment. They found people with a history of repeated concussions, and then as what they thought might be a group to compare to some American football linemen with no history of concussions to compare with. They found linemen with the same issues despite no concussion history. This raised the possibility that worrying about severe hits that result in a concussion was possibly missing a larger issue. It seems our understanding of brain injury and even how it comes about may be inaccurate.

javagram 7y ago
American football involves constant collisions. That type of research suggests that even without a “concussion” the same type of damage can occur from repeated, more mild collisions. Cycling seems like a different order entirely, it’s extremely unusual for a cyclist’s head to hit anything and only happens during an accident or mishap.
- JauntyHatAngle 7y ago
  Soccer is a good example. You are rarely concussed from heading a soccer ball, but there is some evidence that players may suffer brain damage from from repeatedly heading the ball. https://www.sciencedaily.com/releases/2018/04/180424112923.htm https://www.sciencedaily.com/releases/2018/04/180424112923.h...
  - scarejunba 7y ago
    45 headers in two weeks were enough. Holy Jesus! Thank you for bringing this to my attention. I probably won't heal but maybe I'll protect from damage.
mabbo 7y ago
> They found linemen with the same issues despite no concussion history. With no reported concussion history.
- grogenaut 7y ago
  Reported can mean many things. If I was asked in such a study I would bring up the 7 our situations I know of where I even suspected I might have had a concussion, mostly snowboarding related actually (with helmet), odd given I also played 9 years of football and 9 of Aussie rules. None of them with concussion effects other than maybe I'm done for the day (you tend to take bigger falls when you are tired). Also seen enough concussions and evaluations to be able to identify those exhibiting obvious symptoms tho I'm not trained in it. I would let the people running the study decide how to classify them. Its also not like there is a standard "reporting" form for concussions. Especially further back and esp if you had a team doctor.

Alex3917 7y ago

> They can get away with it because it’s such an easy marketing sell- most people think their life is worth more than $250, so any helmet tech is a bet on the order of Pascal’s wager. I think this is basically accurate. Even if you have zero expectation that either this or MIPS or whatever works, I don't see how anyone who has seen Crash Reel or any of the football-related concussion documentaries could possibly not spring the extra few bucks. Someone should put together a list of the cheapest or highest expected-value Pascal's wagers. Even things like flossing your teeth are a good example, where it's clearly good for your gum health even though the Cochrane research is equivocal. (Although using a WaterPik is probably better, especially if you do so in addition to flossing.) Anyway if you haven't seen it, this movie will change the way you think about sports: https://www.youtube.com/watch?v=c1hxtjlbTHI https://www.youtube.com/watch?v=c1hxtjlbTHI

stbtrax 7y ago
If you have long hair, MIPS will eat it and not let it go. I don't get how MIPS is different from just wearing a cycling cap
- entee 7y ago
  MIPS (you seem to know this, but many might not) is an internal layer in the helmet, usually a very thin rigid plastic layer, that has some elastic nubbins/supports between it and the outer helmet styrofoam shell. This means that the inner shell is free to stay put while the outer styrofoam shell rotates. This would be different than a cap in that the elastic nubbins should dissipate some of the energy. All this is a bit speculative, but that's what I'd go with.
deleted 7y ago
[deleted]
frabbit 7y ago
Interesting take-away from having watched football-related concussion documentaries. For a long period of time football players were told that if they wore helmets they were protecting their head. So they were lured into dangerous behaviors. If cycling is a dangerous as playing football (it's not) then bicycle helmets would fulfill the same misleading role as football helmets. As it is cycling is relatively safe and helmets are observed to make no measurable difference in outcomes[1] 1. https://www.badscience.net/2013/12/bicycle-helmets-and-the-law-a-perfect-teaching-case-for-epidemiology/ https://www.badscience.net/2013/12/bicycle-helmets-and-the-l...

jpmattia 7y ago

> most people think their life is worth more than $250 FYI, I just bought the Bontrager wavecell last weekend for $150 at REI. It was a no-brainer, so to speak. [I just had the worst crash of my life 2 weeks ago. I incurred nothing worse than scrapes and bruises, mostly because the helmet did its job, but needed to replace it after the crash.]

iamnotacrook 7y ago
If the helmet wasn't damaged in the crash it meant the energy was harmlessly transferred into your head. You want the helmet to be damaged/destroyed.
- entee 7y ago
  It's often not clear whether the energy went into the helmet. It could have cracked something internally or substantially weakened the EPS under the plastic shell without it being super visible. Better to not risk it: serious crash, replace helmet.
- jpmattia 7y ago
  If you didn't know better, it looked like someone hit the helmet with a hammer a couple of times. So yes, some amount of kinetic energy was dissipated in deformation of the plastic rather than my skull. I was more than a little grateful.
- dahart 7y ago
  > If the helmet wasn't damaged in the crash it meant the energy was harmlessly transferred into your head. Foam can and does distribute and absorb shock without being significantly damaged or destroyed in less severe collisions, crashes that can still put you in the hospital without a helmet. I would maybe describe how helmets work as having a shock-absorbing cushion that slows deceleration of it’s contents. Talking about “energy” is bound to be misleading or confusing, since from a given speed, you always transfer the same amount of energy no matter how you stop, whether it’s a sudden strike against concrete or a slow gentle braking, or even waiting several minutes for air and tire friction to wear out all your kinetic energy. I don’t want the helmet to be damaged or destroyed only because that means the crash is bad or severe.

hevi_jos 7y ago

>The dirty secret is that literally nobody has ever seen a brain rotate inside a skull and result in concussion. Are you sure?. We have a thing called tomography with things like xrays, magnetic resonance that let's us look inside bodies. Experiments were done in the past with animals that have a similar brain to us, specially aviation military, that were extremely interested on concussions. At least they have x-rays photography of impacts. By the way all this research led to car's seatbelts. Thousands of brain surgical procedures are done each year, there are experts in the anatomical features of the brain, and we have detailed maps of sliced brains and complete heads. Tens of thousands of people die in car accidents and hundred of thousands are injured. Insurance companies have extensive documentation on those. We know the physical properties of those things and we have things called computers that let us do very complex models about the brain with finite elements or just analog 3d printed models with gelatin and plastics. To say that nobody can imagine a brain in motion, so everything is a hypothetical mechanism is quite unfortunate. We know a lot about what happens more or less. Things have improved dramatically for people like motorbike racers because we actually know a lot and lots of lives had been saved because of that.

parsimo2010 7y ago
Literally all those things you mentioned happen in static environments. Note that I said we can’t image a brain in motion, all we have for that are computer models. Sure, they’re plausible, but we can’t even agree on what crashing forces applied to the cranium look like, let alone the resultant brain movement and pressures induced. You can’t CT a brain as the head is falling. Nobody has ever drilled holes in someone’s skull and mounted pressure transducers inside the skull to truly validate the pressures during impact. All the “validation” has happened in lower fidelity domains (particularly the time domain), this is a bit like claiming that you know calculus because you can do addition really good. Every mechanical engineering student will tell you that dynamics is a different beast than statics. Fancy computer images does not the truth make. Note that I’m not saying that a MIPS or WaveCel helmet is worse than the previous generation, I’m just pointing out that the timing in which these features appeared on the market is suspect, which causes me to suspect the “science” behind it. It is most likely that these antirotation features don’t make the helmets worse but also not any better.

sliken 7y ago

I agree. I've raced on road, off road, been a bicycle messenger, and commuted on bike to work every working day since 1994. Accidents happen and helmets help. The most dangerous thing about a bike accident is generally the vertical distance. Try laying down on concrete, lift your head up an inch, and drop it. Keep in mind that when falling your acceleration is 9.8 m/sec/sec, so a 10 inch fall is worse than 10 times as bad as one inch. The MIPS and Wavecell seem to assume that helmets grab the road with great traction and then snap your skull producing a large rotational acceleration so great that your brain falls behind. In my experience helmets (which are at first approximation spherical) hit in the center, easily skid, and induce approximately zero rotation in your skull. I do recall in the 1990s or so that as brands switched from a heavier plastic shell (like the ancient bell helmets) to the then common nylon sleeve over the styrofoam that one manufacturer picked a particularly high friction material which did cause additional injuries. Once that was fixed everyone was happy again. So absorbing energy from the fall is great. Playing games with additional layers with low internal friction or fancy ways to collapse is useless. I'm not completely against the idea, but seems laughable to pay 3-6X for something unlikely to help. Bike helmets that meet the toughest impact standards are available for $50 or so. I personally have fallen many times, had my helmet skip many times (the longest was more than 10 feet) and never noticed my helmet gripping the ground and trying to torque my head.

tzs 7y ago
> Keep in mind that when falling your acceleration is 9.8 m/sec/sec, so a 10 inch fall is worse than 10 times as bad as one inch. Shouldn't that be sqrt(10) times as bad? The distance fallen under constant acceleration g for t seconds is 1/2 g t^2, so it takes sqrt(10) times as long to fall 10 times as far. The velocity after falling t seconds is g t, so falling sqrt(10) times as long gives a velocity of sqrt(10) times as much.
- sliken 7y ago
  Ha, sorry, yes. I confused 10 times as long with 10 times as far... I should have double checked the math. Still dropping your head an inch (painful) is a nice reminder of how much energy is involved from normal riding height.

olooney 7y ago

why not use an animal model?

jpmattia 7y ago
How cruel.
- ipsum2 7y ago
  Cancers are regularly induced in mice and rats. Almost every single medicine has been tested on animals before they're used on humans. Modern medicine is built on animal models. It's unfortunate, but a sufficient tradeoff a vast majority of people are willing to make.
  - jpmattia 7y ago
    I’m not entirely sure what you are saying. Is it not cruel, or that the cruelty is OK?
    - Biganon 7y ago
      They're saying it's cruel, but some cruelty is sometimes needed if the benefits for humanity are worth it.
parsimo2010 7y ago
Because diagnosing an animal concussion is harder than diagnosing a human concussion. Animals can’t tell you if they have a headache, light sensitivity, nausea, etc. You would only be able to diagnose the worst class 3 concussions where the animal can’t even walk straight. It’s probably not ethical to subject animals to that much pain if you can’t even confirm half of the injuries.
- adrianN 7y ago
  Aren't concussions visible in MRI?

ramy_d 7y ago

My understanding of MIPS was that it was meant to redirect linear force against the head, such as banging your head against a car in a relatively straight line, into a rotational force that would let the helmet slip off the head and that would reduce the amount of trauma to the skull. I never heard of anything about "brain rotation"

parsimo2010 7y ago
This explanation of MIPS goes pretty much all-in on it being about rotation: https://www.torpedo7.co.nz/community/help-and-advice/bike/gear-advice-technical-info/3604 https://www.torpedo7.co.nz/community/help-and-advice/bike/ge... Edit if you prefer it directly from the marketing horse’s mouth: https://mipsprotection.com/ https://mipsprotection.com/
- ramy_d 7y ago
  When you have suffered a concussion or an even more serious damage to the brain, rotational motion to the brain is the most likely cause. from the mips protection website, you are correct and i understood it upon first reading as something else
  - taneq 7y ago
    Wow, given that they're talking about something that invariably has a significant linear acceleration factor, that's a pretty... confident... way to put it.

zachrose 7y ago

> I bought a Giro Atmos over a decade ago and never needed to upgrade... I’m sure you’ve heard this but they say to replace a helmet every two-three years even if it hasn’t been in a crash. It’s up to you whether you think that makes sense, but I’d sooner believe it than not.

TheSpiceIsLife 7y ago
It'd be hard to miss the potential for that to be marketing-speak for "buy more helmets more often", especially given the context of the comment you replied to.
- adrianN 7y ago
  I've had old helmets develop cracks spontaneously so this is marketing that I tend to believe.
  - TheSpiceIsLife 7y ago
    By old do you mean two years or twenty?
    - adrianN 7y ago
      I think that helmet was less than four years old. And it wasn't a cheap one either.
      - jacquesm 7y ago
        That's a warranty issue more than a reason to buy another one of the same brand.
Cyclone_ 7y ago
I've raced for about 6 years now and have not replaced my tri helmet, but have replaced the one I use when I'm on my road bike (only because it broke in a crash), where did you hear that you should replace the helmet that frequently?

petre 7y ago

I believe all the current Giro helmets are MIPS now, even the cheap ones. In fact I was contemplating of getting one myself, not necessarily because of MIPS but if it's safer and also looks good, cool.

taneq 7y ago

> The manufacturers noticed that helmet sales were declining, and all of a sudden “new science” appeared with a theory about concussions being caused by brain rotation and MIPS technology helps prevent that. > There isn’t an ethical test for blunt force trauma in real life conditions, and bike crashes are very rarely reported if they don’t send the rider to the hospital. There's one ethical source of data - televised bike races. Surely there are enough crashes recorded in publicly accessible videos to provide a fairly representative sample of how a human head moves when the helmet it's wearing hits the road. > They can get away with it because it’s such an easy marketing sell- most people think their life is worth more than $250, so any helmet tech is a bet on the order of Pascal’s wager. It's exactly the same with motorcycle helmets. You can get a DOT approved helmet for $150, but the general perception in the community is "if you have a $150 head, wear a $150 helmet". Then everyone pays $800 for helmets designed to European standards which are meant for racing, and give dubious benefit if any at normal road-going speeds (eg. see https://www.nytimes.com/2009/09/27/automobiles/27SNELL.html https://www.nytimes.com/2009/09/27/automobiles/27SNELL.html).

nradov 7y ago
Most of the crashes I've seen in televised pro races were shot from only a single angle some distance away, and often with obstructed sight lines. So I'm skeptical that those videos will give us useful data on head movement.
- piquadrat 7y ago
  Also, pros crash differently than your typical bike commuter or recreational cyclist. For one, there's a large difference in speed (45+ kph for pros, half of that or less for your typical commuter - somewhat negated by the e-bike boom). Next, pros in televised races don't have to deal with oncoming traffic, so head-on collisions are a non-factor. And lastly, pros know how to crash (tuck in, roll over, dissipate energy over a distance), while non-pros tend to tense up in a crash situation. There's probably other ways in which pros crash differently, making them a less than ideal sample of the overall cycling population.
  - 7y ago

kmonsen 7y ago

Just a quick tip, bike helmets actually have expiration dates and should be replaced every 3-8 years depending on the helmet.

xorcist 7y ago

Wearing a helmet is always better than no helmet. Any helmet. That doesn't mean the technology can't be improved, and there's actual science being done. Brains are being imaged. There are peer reviewed articles published every year that details the challenges of how to model brain damages. It's not fair to brush them off as just an invention in marketing. So far it does seem that measuring impacts at an angle matches real world brain damages better than the older standards of measuring dead-on impacts. That's what "rotational acceleration" means. Acceleration is just another word for impact. It doesn't mean your skull should rotate freely. There are enough indications that this translates to helmet improvements that most consumer organizations have started to recommend them should you buy a new one. That doesn't mean you should throw away your old helmet but it should be enough to disqualify it as "snake oil". This new Wavecel system hasn't been reproduced yet, two testing institutes has so far failed, but it is similar enough to existing cell and slip systems that performance is not likely to be worse.

jchanimal 7y ago
I hope you wear a helmet in the shower and when you drive a car.
- henryaj 7y ago
  How often do you hit your head at 30mph in the shower? Doesn't your car have seatbelts and airbags?
  - sporkland 7y ago
    If you're doing 30mph on your bike you're doing a different type of biking than me and most commuters.
    - massaman_yams 7y ago
      I use the same helmet when commuting and on longer/faster rides.
  - 7y ago

pisteoff 7y ago

Blah blah blah. While I appreciate the skepticism, this is BS only for the sake of it (as so many HN comments are). You instantly lose credibility with this line: "I bought a Giro Atmos over a decade ago and never needed to upgrade because the top of the line helmets were only a couple grams lighter, after a decade of “improvement.” I hope you've since replaced it. General guidelines are to replace a helmet every three years due to material degradation and UV damage. Yes, you are correct that there is a marketing element. Likewise, you are correct that people value their lives over $250 price tag. As a bit of antidotal evidence, I had a fall this weekend on Evolution trail on Galbraith MTN in Bellingham, WA. I fell from about 6-7 feet up on a feature called the Stinger, a long, super fun north shore style bridge (watch some youtube videos if you want to see it). My face and head were impacted in the fall and I suffered, what I think is, a very mild concussion. I replaced my helmet afterwards as per the recommendations. I also have a history of TBI caused by a cycling accident where wearing a helmet saved my life. I am absolutely going to buy something that even vaguely suggests an advantage for injury prevention. Mountain Biking is, after all, and inherently dangerous sport. As you suggest, any progress is good progress when it comes to saving lives. But I absolutely disagree that it "is a bet on the order of Pascals wager," especially when it seems I myself have made that wager and come out ahead. So, with the utmost respect, unless you are a leading researcher in this field, STFU.

dwohnitmok 7y ago
This reply doesn't seem to be in line with HN guidelines. "Be kind. Don't be snarky." and "When disagreeing, please reply to the argument instead of calling names. 'That is idiotic; 1 + 1 is 2, not 3' can be shortened to '1 + 1 is 2, not 3.'" https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html