Helmets - the definitive thread.. ** Mod Note - Please read Opening Post **

tomasrojo

As an aside on woodpeckers, I read about some high-speed imaging they did on woodpeckers, and one strategy they have for avoiding brain damage is to line up the skull, beak and target very precisely every single time so that there is no rotational acceleration imparted to the skull. I think there's damping material at the base of the beak too, which I guess is somewhat like helmet liner, but probably to assist in preventing the skull being thrown back by recoil and to absorb shockwaves.

Chips Lovell

The Davestator wrote: »

Do you wear a helmet if sking?

I don't.

CramCycle

magicbastarder wrote: »

i once did pick up a minor injury on a bus - i was standing in the middle door stepwell about 20 years ago, on the number 10, and a taxi passenger doored a cyclist right into the path of the bus; needless to say the driver had to stand on the brakes. i went a bit arse over tit - i'd nodded off slightly while standing, and managed to somehow sprain my ankle.

I once cartwheeled down a bus as some smart arse, seeing me climb over some obstructions, thought it hilarious to grab my foot and flip me. I actually managed to not only cartwheel but also land on my feet and get off the bus quicker than usual. I thought I looked like this:

https://www.youtube.com/watch?v=D4G-24i7km4

In reality I probably did not.

Roadhawk

mcgratheoin wrote: »

I take it you wouldn't be a helmet fan for cycling either so if 30km/h is practically stopped.

I was initially of the impression that all cyclists should wear helmets for added safety but my view on this has recently changed. I have come to learn that people have a choice of how safe they want to be.

Wear the helmet...dont wear the helmet...who really cares? I know in my car i have a seat belt and an airbag so i feel safe enough for how i approach the road.

However, when I do cycle I always wear a helmet.

ThisRegard

magicbastarder wrote: »

would be interesting to see the stats on crashes buses are involved in, and what speeds they happen at; they don't accelerate very fast and are big and generally visible. i suspect you're more at risk of being driven into while in a car than while on a bus.

also worth mentioning that in an equivalent incident (let's say a bus being hit by a particular type of vehicle), the deceleration or acceleration you experience on a bus will be much less pronounced than in a car.

When a bus hits something it tends not to come to a sudden or quick stop due to its mass, unlike a car, so the forces at play are different.

There's a video a couple of days ago in the dash cam thread with a car hitting a London bus head on at a relatively low speed. The car was thrown into the air and wrecked, not a bother for the bus and everyone seemed to have sauntered off.

Jep Gambardella wrote: »

I don't.

I do, I have some varying degree of control over my own skiing, but not others.

AndrewJRenko

Some excrement hitting some fans in the UK - check out the responses to the Nationwide tweet

https://twitter.com/AskNationwide/status/887958891618848768

rubadub

AndrewJRenko wrote: »

Some excrement hitting some fans in the UK - check out the responses to the Nationwide tweet

https://twitter.com/AskNationwide/status/887958891618848768

For a second there I thought the netherlands were bring in compulory helments.

Helmets for visting Uk stag parties in the netherlands would make more sense.

I love Sean nos

magicbastarder wrote: »

would be interesting to see the stats on crashes buses are involved in, and what speeds they happen at; they don't accelerate very fast and are big and generally visible. i suspect you're more at risk of being driven into while in a car than while on a bus.

TfL should have some. I read somewhere that TfL buses are involved in 60+ collisions per day. :eek:

conkennedy

skeleton_boy wrote: »

A helmet will not protect you from concussion.

Concussions are caused by your brain jolting inside your skull. Unless you can wrap your tongue around your skull like a woodpecker, no helmet will prevent a concussion.

Google nfl helmets and concussion and you'll find plenty of evidence to support this.

From experience, no, a helmet won't prevent concussion. It will split upon impact as it absorbs the force, like it's designed to do. This way your skull doesn't split.

CramCycle

conkennedy wrote: »

From experience, no, a helmet won't prevent concussion. It will split upon impact as it absorbs the force, like it's designed to do. This way your skull doesn't split.

How do you know there is not a reduced risk your head will hit something without a helmet on due to decrease in size? Or a reduction in rotational forces due to reduction in weight? There are pros and coins to wearing a helmet. Alas, like many things, it is not black and white.

conkennedy

CramCycle wrote: »

How do you know there is not a reduced risk your head will hit something without a helmet on due to decrease in size? Or a reduction in rotational forces due to reduction in weight? There are pros and coins to wearing a helmet. Alas, like many things, it is not black and white.

Advice from the doctors who saw to me after being hit.

CramCycle

conkennedy wrote: »

Advice from the doctors who saw to me after being hit.

I didn't realise that was a medical doctors field of expertise. I would have thought that such a throwaway comment from a medical doctor would carry no more weight than mine.

Where you wearing a helmet or did they say you should have been?

Where they able to calculate the increased force from wearing the helmet and what contribution to the overall force to your head this added.

I know nothing of your accident, didn't witness it so can't comment on it, everyone is quick to say the helmet saved their lives after a bike crash, but can they 100% say that the crash would have been as bad if they were not wearing it. Or where you not wearing a helmet and they commented that if you had been it would have been far better for you?

conkennedy

CramCycle wrote: »

I didn't realise that was a medical doctors field of expertise. I would have thought that such a throwaway comment from a medical doctor would carry no more weight than mine.

Where you wearing a helmet or did they say you should have been?

Where they able to calculate the increased force from wearing the helmet and what contribution to the overall force to your head this added.

I know nothing of your accident, didn't witness it so can't comment on it, everyone is quick to say the helmet saved their lives after a bike crash, but can they 100% say that the crash would have been as bad if they were not wearing it. Or where you not wearing a helmet and they commented that if you had been it would have been far better for you?

Yes, I was wearing a helmet at the time I was knocked down.

No, the force was not measured, I didn't have an accelerometer or a force sensor fitted to the helmet.

What I can say is the helmet did it's job, it split, I didn't have a fractured skull.

So, anecdotally rather then empirically, yes, you could say the helmet saved my life.

rubadub

CramCycle wrote: »

How do you know there is not a reduced risk your head will hit something without a helmet on due to decrease in size? Or a reduction in rotational forces due to reduction in weight?

conkennedy wrote: »

Advice from the doctors who saw to me after being hit.

Bizarre how the doctor gave advice on all those 2 specific points -points which most people do not even think/know about.

It would be interesting to know how many cracked helmets would have resulted in a cracked skull, probably a very small minority, esp as many would not have even hit their heads at all. I am sick to death of hearing that line.

I have said before if I was to wear a helmet 24/7 I reckon I would crack a good few over the course of a year. Helmets are designed to crack easily, thats the point, imagine people seeing a cracked car bumper "jaysus, lucky I had the bumper, the car would have been a write off without it"

Did you ask advice from the doctors about what other circumstances/activities they would advise you to wear a helmet, e.g. while drinking, or in a car.

I love Sean nos

I read an interesting blog post on helmets over the weekend. Need to go find it. It discussed the accidental bundling of sports cycling and transport cycling and the need for helmets for either.

Chuchote

I love Sean nos wrote: »

I read an interesting blog post on helmets over the weekend. Need to go find it. It discussed the accidental bundling of sports cycling and transport cycling and the need for helmets for either.

Big difference, it's true, though with the state of the roads...

tomasrojo

I've never been clear about whether a helmet cracking is a net benefit to the wearer or not. The main way they work is supposed to be linear deceleration when the liner compresses, so the liner splitting means no more compressing. I've heard people say that splitting is part of the design, as it dissipates energy, and other people say that the helmet has failed at this point and is not doing its job anymore.

Either way, the force at which helmets split is somewhere just more than the force exerted by 5kg falling 1.5m, because that's the test they're designed to pass: 5kg headform placed in the helmet, helmet dropped 1.5m onto an anvil.

Bit hard to calculate, and depends on how high the helmet bounces after impact. Maybe 250-700N?

So, while that might be enough force for a simple fracture, splitting the skull would require a lot more than that, I think (I read that about 5000N required at the weakest point, the temples). Skulls are a lot tougher than expanded polystyrene anyway. I think that's an uncontroversial statement.

magicbastarder

i dunno, all this 'what if' stuff in relation to helmet wearing (when you assume the accident - i.e. absent of effects of helmet wearing and the likelihood of an accident happening in the first place) - that it can increase rotational forces, it can mean an impact where without a helmet there would be none, etc., it seems somehow reminiscent of the argument that because in something like 5% of car crashes, a seatbelt may make things worse for you, that you have a rational argument not to wear one.
i don't think i've ever seen any figures on the above scenarios, but would be happy to see any if they're available.

there seems to be a little bit of 'absence of evidence=evidence of absence' going on - that the fact that someone has had an accident with a split helmet and a head that's OK, somehow, i'm meant to believe that a helmet would have at best neutral, at worst a negative effect on the health of their head. the fact that their head is OK is considered an irrelevant piece of data.

in short, when someone comes on with an 'i had an accident and split my helmet', and people are quick to jump on them and say they can draw no conclusions on that, i'm just a little sceptical. and i'm probably not making much sense, i'm three pints and a nice whisky into the evening so will probably make better sense in the morning.

CramCycle

magicbastarder wrote: »

in short, when someone comes on with an 'i had an accident and split my helmet', and people are quick to jump on them and say they can draw no conclusions on that, i'm just a little sceptical. and i'm probably not making much sense, i'm three pints and a nice whisky into the evening so will probably make better sense in the morning.

You are of course, talking complete sense. The thing is that when someone uses this anecdote as evidence that helmet wearing is a positive thing, when from my understanding, at a population level, all indications are that helmet wearing provides no net positive or negative.

I am not saying helmet wearing is a negative, I am just saying it is not the positive that many would have you believe. For the every day cyclist, typically, maybe not posters on here, there are several things you could do in regards behaviour change that would be far more benefical to your health and well being than a helmet will ever be. Using a helmet as thing to distract from the other major issues that affect cyclists pisses me off and is the reason I am generally so vocal in dismissing pro helmet arguments. I am not anti helmet, I am anti using helmets as a distraction for the real issues affecting everyday cyclists. Unfortunately, that usually ends up with me coming out as some anti helmet crank. I don't care whether everyone wears one, or no one wears one, I honestly believe, there is no net benefit for the entire cycling population.

It is a sign of the disrespect that cyclists are shown on the road when "wasn't even wearing a helmet" can somehow be used as a mitigating factor when a car runs a person over. The fact that I have to try and prove the currently unprovable just to show that it is not the major issue, is of concern. I have heard people say it, all my life, "look at that lad over there, not even wearing a helmet". How is that even a topic for discussion, it almost implies, that behaving recklessly around cyclists is acceptable because in that persons mind, they have convinced themselves that the cyclist already doesn't care.

The fact that there is need for a god damned helmet megathread on a cycling forum which covers anything other than price, comfort and maybe aerodynamics is puzzling to me in the extreme.

I think I should go to bed.

magicbastarder

and i think this is one of the crucial aspects here; to borrow a line i think i remember hearing about the difference between the republicans and the democrats (albeit dating from a decade or two ago, as much has changed); that republicans unite along their common goals, and democrats split on their differences; and i think this thread is evidence of a democrat approach to helmets.

if someone comes in and says 'i had a crash today and i think the helmet was a benefit', i think it's unhelpful to denigrate their experience as a) you were not there, and b) you were not there. there's probably a c) in there too, but at a distant third. their judgement call is based on the 'here's the scenario, and the variable of wearing a helmet - or not - is much easier to calculate as an effect on how my head came out than on how likely the entire scenario was in the first place'. but generally, if someone reckons the helmet saved them from injury, i'll take them at their word.
FWIW, the one time i did crash, i reckon the helmet *may* have saved me from a broken nose. i don't know what part of my face would have otherwise absorbed the energy which crushed the front of the helmet. i do believe (maybe 'have a hunch' is a better phrase) that *once an accident is in progress* a helmet is going to be of benefit. but it's that caveat which is the subtlety which we should not engage in.

it's like (to shoehorn another analogy in) abandoning daylight savings time; the argument is that lives would be saved by moving the daylight back to the evening, when people are tired and benefit more from the daylight; but the tabloids are more easily going to be able to regale us with tales of people who died in the morning, than they are to show us the people whose lives were saved by simply not being in collisions in the evening.

in short - i don't think it's worth fighting over the anecdotes. if someone reckons they're better off for having worn a helmet in a crash, they probably are. it's the tens of thousands of helmets which never go to helmet heaven which is the real data.

Arcade_Tryer

CramCycle wrote: »

You are of course, talking complete sense. The thing is that when someone uses this anecdote as evidence that helmet wearing is a positive thing, when from my understanding, at a population level, all indications are that helmet wearing provides no net positive or negative.

I am not saying helmet wearing is a negative, I am just saying it is not the positive that many would have you believe. For the every day cyclist, typically, maybe not posters on here, there are several things you could do in regards behaviour change that would be far more benefical to your health and well being than a helmet will ever be. Using a helmet as thing to distract from the other major issues that affect cyclists pisses me off and is the reason I am generally so vocal in dismissing pro helmet arguments. I am not anti helmet, I am anti using helmets as a distraction for the real issues affecting everyday cyclists. Unfortunately, that usually ends up with me coming out as some anti helmet crank. I don't care whether everyone wears one, or no one wears one, I honestly believe, there is no net benefit for the entire cycling population.

It is a sign of the disrespect that cyclists are shown on the road when "wasn't even wearing a helmet" can somehow be used as a mitigating factor when a car runs a person over. The fact that I have to try and prove the currently unprovable just to show that it is not the major issue, is of concern. I have heard people say it, all my life, "look at that lad over there, not even wearing a helmet". How is that even a topic for discussion, it almost implies, that behaving recklessly around cyclists is acceptable because in that persons mind, they have convinced themselves that the cyclist already doesn't care.

The fact that there is need for a god damned helmet megathread on a cycling forum which covers anything other than price, comfort and maybe aerodynamics is puzzling to me in the extreme.

I think I should go to bed.

Yep, you're absolutely right. For the population, helmets are not a significant factor in terms of cycling safety, on city streets especially. The major issues are close passes, cars pulling out in front, and doors opening. These are all problems predominantly caused by motorists. Changing motorist behavior is far more beneficial long term than forcing cyclists to wear helmets, which only reinforces the idea of cycling being inherently dangerous. Not wearing a helmet may also lead cyclists to be more cautious ala the Peltzman effect. Helmets really are way down the list of things that will lead to increased safety for cyclists in cities and towns.

tomasrojo

Just for clarity as well: I'm not gainsaying the experience of conkennedy, or saying the helmet did nothing. It's just doesn't seem that the sort of forces that split a helmet are comparable to the forces that split a skull. (Most head injuries don't involve split skulls; that doesn't mean they're all or mostly trivial by any means.)

It's also unlikely they never make any positive difference; they definitely reduce linear acceleration in some scenarios. But they don't seem to make a huge amount of difference when you take large numbers of cyclists into consideration. There are a lot of posited reasons for this, which I'm not going to reiterate here, as it's quite a long argument, for which reason this thread exists.

To say something short: I suppose it's a bit like buying lottery tickets. I can't say that any individual buyer won't win a big prize. But if you look at a very large number of ticket buyers, you can hazard a very good guess as to how many will win a big prize. Except the big prize in this case isn't one you want to win. And the people who don't buy a ticket seem to win about as often as the people who do.

tomasrojo

magicbastarder wrote: »

in short - i don't think it's worth fighting over the anecdotes. if someone reckons they're better off for having worn a helmet in a crash, they probably are. it's the tens of thousands of helmets which never go to helmet heaven which is the real data.

But you know the way these things go (and why this quarantine thread exists). A lot of these anecdotes don't just say that they person thinks things would have been worse without the helmet. They say that the helmet saved their life, and if you don't wear one, you're a fool. Sometimes they add "but it's your funeral" if they're feeling generous.

And the bigger-picture data don't support this argument all that strongly.

plodder

tomasrojo wrote: »

I've never been clear about whether a helmet cracking is a net benefit to the wearer or not. The main way they work is supposed to be linear deceleration when the liner compresses, so the liner splitting means no more compressing. I've heard people say that splitting is part of the design, as it dissipates energy, and other people say that the helmet has failed at this point and is not doing its job anymore.

Either way, the force at which helmets split is somewhere just more than the force exerted by 5kg falling 1.5m, because that's the test they're designed to pass: 5kg headform placed in the helmet, helmet dropped 1.5m onto an anvil.

Bit hard to calculate, and depends on how high the helmet bounces after impact. Maybe 250-700N?

So, while that might be enough force for a simple fracture, splitting the skull would require a lot more than that, I think (I read that about 5000N required at the weakest point, the temples). Skulls are a lot tougher than expanded polystyrene anyway. I think that's an uncontroversial statement.

Whatever energy is absorbed by the helmet in cracking, is energy that would have been absorbed by your head otherwise, is it not? There was a photo on twitter of Mark Cavendish's (I think) helmet after his crash in the TdF. It was in bits and they definitely offered the view that it was helpful to him. By the way, I agree with the previous points. Helmets are not a panacea (if that's the right word). They are not going to prevent all injuries to the head. How many they do protect against is open to debate, but I just find the inconvenience of wearing one is so minor in comparison.

tomasrojo

plodder wrote: »

Whatever energy is absorbed by the helmet in cracking, is energy that would have been absorbed by your head otherwise, is it not? There was a photo on twitter of Mark Cavendish's (I think) helmet after his crash in the TdF. It was in bits and they definitely offered the view that it was helpful to him.

The way it's often phrased is that the liner decelerates the skull, a process that ends when the liner cracks. Up to that point, if the liner has been compressing, it should have been helpful. But it's really not a huge amount of deceleration. And modern helmets with more vents require a stiffer liner to pass the anvil drop test, mentioned above. The problem here is that the liner doesn't compress much at first and then suddenly breaks. At least, that's what one of the testers wrote a good few years ago, when looking at liners from collision aftermaths. Not sure whether that's changed.

Some people claim that the cracking itself is helpful, on top of the compression, but I'm not sure that's true.

The current helmet designs (with the exception of Philips helmets) don't address rotational acceleration, which is another issue in the mix.

It's hard to say in individual cases how much difference was made. In particular, people are very quick to make claims based on individual cases, and dismiss studies of very large numbers of people. I have the opposite inclination (well, not "dismiss", but take with a pinch of salt).

In a low-speed fall, where the head strikes the ground perpendicularly, with no rotation, I can't see how the helmet wouldn't help, most obviously by minimising scalp damage. It's not a type of fall people worry that much about, maybe.

conkennedy

tomasrojo wrote: »

Just for clarity as well: I'm not gainsaying the experience of conkennedy, or saying the helmet did nothing. It's just doesn't seem that the sort of forces that split a helmet are comparable to the forces that split a skull. (Most head injuries don't involve split skulls; that doesn't mean they're all or mostly trivial by any means.).......

In my case a car pulled out on me on a roundabout, I hit the side of their car and seemed to bounce back. It looks like I fell to the left and landed on my coccyx and then the back of my head hit the ground.

I say 'seemed' as I don't remember the impact or the following 40minutes. And I still don't.

So, no a helmet won't protect the cyclist in all cases, only your head in some cases. It won't protect your wrist or collar bone from breaking and it won't protect you from a crush injury from a truck. And I'm not sarcastic. We have to remember the most common types of cycle related injuries don't involve the head.

When I went to the hospital, I brought the helmet with me as I hadn't reviewed the video footage at that point.

What I can say is what the doctors told me.

Do I believe the helmet did its job? Yes. Would I be more hurt if I wasn't wearing one? Probably.

A concussion is a b1tch. It really is.

So is a sprained coccyx. And no, a helmet on my arse isn't practical

I won't say I wear a helmet EVERY time I go out. I don't. I wear one when I'm training, on a sportive or out with the club, etc. But when I'm going down to the shops with my daughter to get an ice cream, I don't. But she does.

tomasrojo

Oh yeah, totally fair enough.

(Just as an aside: as said a few posts back, it has been claimed fairly recently that sports helmets as currently designed don't prevent concussion. I think RobFowl was at a conference in Dublin where it was discussed, and it's been said plenty of times in the context of NFL injuries. I don't know whether it's true, and I don't even know who knows that they don't know, if you see what I mean. I keep hearing different theories about what even causes concussion.)

conkennedy

tomasrojo wrote: »

Oh yeah, totally fair enough.

(Just as an aside: as said a few posts back, it has been claimed fairly recently that sports helmets as currently designed don't prevent concussion.....

Well, mine certainly didn't prevent a concussion!



14 weeks of the worst headaces you could ever imagine! At its worst, 8 severe pains evey hour each lasting from a couple of seconds to a couple of minutes. Sensitivity to light and changes of sound. Lack of concentration, slower processing of information and zoning out.

Glad that has all.......

.... passed. Yes, all passed.

tomasrojo

That's awful.

conkennedy

tomasrojo wrote: »

That's awful.

I tell ya!

Before, I thought a concussion was just a bang to the head and dizziness.

It's much more than that.