Mvcrash

My stupidity is in the fact that even took up this argument on a website. I yield to your superior intellect and ability to regurgitate facts. Don't wear a helmet that is your right. I hope you live a long and healthful life and enjoy your bike riding. (I am NOT being sarcastic on this one). I have seen too much death and human wreckage to ever wish it on anyone. If you'd ever really like to dicsuss the issue, drop me a PM and I'll provide a phone number. I'm not as dumb as I look.

Oh...I read that article as well.

meanwhile

Arguing a subject without finding out what the facts are is stupid, yes.

And therefore have the urge to persuade people to take useless safety measures rather than ones that are effective. (Or indeed efficacious.) You're a saint!

Really, NO ONE WANTS ANYONE TO DIE. But if you are going to argue about stuff, then you should know basic facts first. Otherwise people will have to waste their time correcting the nonsense you spout, like discredited studies and bad physics.

FBinNY 

It doesn't have to make a significant difference, only enough of one to change the outcome. That's what I mean by a critical difference. In a crash with impact in the band of effectiveness (not enough to kill no matter what, nor not likely to cause injury anyway) a helmet can work at the margins, and change the outcome from death or serious TBI to milder TBI, or from mild TBI to no TBI.

It's that kind of shift at the margins of the effectiveness band that would make a helmet worthwhile. I don't opt to wear a helmet, not because I don't believe that it can make a critical difference under the right conditions, but because I consider the risk of an accident that would fall within that band to be too low to bother.

To me helmet effectiveness odds are like the sodium lines in a spectrum. They're bight, but very narrow. But this is a personal decision based on my own riding habits and risk tolerance, and I'm not selling the idea that it's for everybody. My only reason for posting was to counter the "inevitable crash" argument by some people here.

CarinusMalmari

Most Dutchies are already well aware of that fact long before they graduate from kindergarten, thank you very much. But unlike some of you guys we don't consider bicycle crashes to be catharsis inducing life-altering events that will lead to teary-eyed stories about how we barely made it out alive. We consider them as usually painful and embarrassing inconveniences, despite (or maybe because) we don't wear helmets.

And with good reason, because only 8000/year or so are severe enough to warrant treatment in a hospital, and around 200/year are fatal. Now I don't know the exact number of bicycle crashes, since no one bothers to keep tabs on those. But with 13,5 million regular cyclists, and about 5 million taking to the road on every given day, the amount must be staggering. Even with a conservative estimate only a fraction of a percent of bicycle crashes is serious, and the amount that's fatal is nil. The amount in which a helmet would have made a difference is even more underwhelming.

tl;dr Yes I know, but the idea of a bicycle crash doesn't really scare me, because they are mostly harmless.

meanwhile

The DTI study says that, at most, 15% of fatal accidents are in the helmet band. And I emphasize "At most", because that assumes the helmets work as well as they are supposed to re. eg shell integrity, and that's very, very doubtful.

I-Like-To-Bike

Thanks for the response. IMO the term "critical" difference does imply significant changes in outcome.

I would not use the adjective "critical" to describe the marginal, minor and/or insignificant changes, if any, that can be expected in severity outcomes from helmet wear. Marginal, minor, or insignificant difference would be more appropriate IMO.

FBinNY 

I'm not a fan of the word "significant" in contexts like these because it means too many different things, ie. significant in numbers, or significant to the friends and family of those affected.

So I chose the word "critical" because I felt it was more focused. You are free to choose words as you see fit, and I'll do the same.

I suspect that you're trying to define my words out of rather than in context. For example, I would use marginal*, to mean at the margins or edges of the band of effectiveness, rather than insignificant. The context would make that clear to any reader except one who prefers debate to reasonable interpretation.

So, while you may not like my choices of words, I'm not writing for you.

BTW- I'm an old fan of MAD Magazine's marginal thinking.

mconlonx

I came into this thread after riding MCs for a couple decades... and wearing a full-face helmet all the time. Regarding motos, I'm an ATGATT proponent.

So when I got back into regular bicycling, I wore a helmet for the same reasons I wore all the moto gear. However, after reading a bunch of arguments, studies, and papers cited in this thread, I became disabused of the preconceived notions I had regarding the efficacy of bicycle helmets. Especially compared to motorcycle helmets. I assumed, incorrectly, that many of the same arguments presented by the MC bare-head brigade which I was hearing repeated here, were bunk, when in fact many of the arguments applicable to bicycle helmets are studied and legit.

Any medical examiner, while a better authority than most, still carries the same prejudices assumed by general population. And while that examiner might say "could" rather than "would," many who pass along such information, especially in this thread, don't make as fine a distinction... Not to mention, who are they to say? Could just as well have said, "Too bad no long hair, could have survived." Or, "Too bad they hit [object], could have survived."

meanwhile

Actually I'd say that FBinNY is using the term very precisely and, in context, correctly. He's saying

1. A helmet can only remove a tiny amount of energy

2. This will rarely be enough to save a life, but it sometimes will be

And both those things are true - a helmet will remove about 150J if it functions correctly, and the DTI figures say that will make a critical difference in, at most, 15% of fatal crashes. His sodium lines imagery is excellent.

(By comparison, I suspect the average helmetoid thinks that a helmet reduces the risk of death by 50 to 90%.)

wphamilton

It's unfortunate that the discredited 85% number is quoted so often, because there is overwhelming statistical evidence that helmets usually mitigate or prevent serious head injury. If I hit the ground, I'd rather have a helmet on. When I hit my head on a cabinet door or a storage shelf, I wish I'd have been wearing one.

But put that into perspective. Cycling doesn't rank very high in the cause of traumatic brain injury. The plurality cause is simple falling (35%) followed by motor vehicle accidents (17%) from the CDC on Brain Injury These are absolute numbers that don't really say much about the danger while involved in an activity - almost everyone walks for example while fewer ride bikes but it's good to keep in mind when the cost to society comes up.

But about that danger specific to the activity. We don't get exact numbers on miles biked, BUT we can use pretty good estimates. It turns out that walking is more fatal than cycling is per mile. In fact twice as likely. (John Pucher, Rudgers University)

So we have in walking a greater risk of fatality than while biking, and tripping on a sidewalk representing the greatest danger of traumatic brain injury. That's the perspective we need.

What is my actual risk of being killed by a car while riding? Given that I don't ride while intoxicated, don't salmon or ride sidewalks, and don't ride at night without lights, and rarely ride remote rural roads, pretty close to zero ... with or without a helmet ...

meanwhile

Secret evidence! That can't be linked!

That's your opinion, not evidence. Different. In fact, the UK's main expert witness in helmet case, a helmet engineer, thinks you're probably wrong - a helmet enlarges the head increasing rotation (the main instrument of neurological damage) and making it more likely that the head will make contact rather than be protected by the fall reflex. These factors are small and wouldn't be significant if cycling helmets absorbed a non-marginal amount of energy, but because the protective effect is so weak they matter a lot.

Anyway: the rest of your post is commendably evidence based, so kudos!

meanwhile

The main killer you haven't mentioned is the combination of junctions and heavy vehicles. Learning where the blind spots are for an HGV would save a serious number of cyclist lives:

Safety tips for cyclists, truck and bus drivers | CAN

I-Like-To-Bike

Have to disagree again about the use of the adjective "critical" as the proper qualifier for likely changes in accident severity that can be expected from helmet wear.
I am addressing the topic from from a risk management perspective. Reducing fatal accidents to a slightly prettier face on the corpse fatal accident, or a catastrophic severity injury to a slightly less catastrophic severity injury, or even a minor/insignificant severity injury to a slightly less severity injury are not significant reductions in risk, nor "critical" changes/mitigation effects in accident consequences.

Given the low probability of a cyclist being involved in any accident involving head impact, combined with the very low probability of helmet wear significantly reducing the overall severity of such occurrences (i.e. mitigating what would have been a catastrophic injury to a minor injury), helmets can make a critical (i.e. significant) difference in accident outcome in only the rarest of accident occurrences.

meanwhile

He's saying that cases where a helmet will make a critical (= life saving) difference are rare. This is exactly correct - they're 15% at most
based on the DTI study. 5% is probably realistic.

FBinNY 

IMO- there are a number of superfluous and misleading adjectives here.

Overwhelming, doesn't belong because while there is some evidence, the fact is that it more underwhelming than overwhelming.
Usually, because so many head strikes (when they occur) are out of the band of effectiveness, that rarely or sometimes may be more appropriate
Mitigate or prevent, choose one, yes helmets often migitate injuries, but prevent is an exaggeration that must be preceded by may to be honest.

So, my cleaned up version of the statement would read something like this "there is evidence that helmets mitigate and may prevent some head injuries". Now for many, that's reason enough, and it's their choice, but hardly cause for the type of ringing endorsement or call to arms we hear so often.

BTW- there's also some info that helmet proponents hate, and that helmets can actually create injuries where none might have occurred. I suspect this is also only within a narrow band, and would concede that on balance helmets do more good than harm, but it's still within narrow bands of effectiveness.

FBinNY 

Feel free to disagree, again, and maybe later for a third or n+1 time. I choose my words pretty carefully, especially here on the helmet thread, but I don't expect nor ask for agreement on either the specific language or implied ideas of my posts.

You can parse the text any way you want, but I suspect that most here are more interested in the ideas expressed than the specific words used to express them.

I-Like-To-Bike

I can agree that life saving difference events are rare; 15% at an extremely generous most, more likely to be a magnitude or two less, though reducing a fatal severity to some sort of catastrophic severity permanently disabling injury is not necessarily something that is all that positive as a result.

I don't believe FBin NY was limiting his critical differences to just altering the outcomes of possibly fatal events but also any severity injury that might be reduced in severity no matter how slight or how unlikely: "change the outcome from death or serious TBI to milder TBI, or from mild TBI to no TBI. "

wphamilton

So commonplace that it's not worthwhile to link.



It's an introductory paragraph defining the context for the general topic. A summary paragraph will also lack new cites of evidence, presenting only conclusions and relating them to the opening paragraph. In this case, with respect to personal risk preferences. Returning to the more general perspective, no new data should be presented there. I do this for the clarity of writing style, and to more effectively engage the reader's interest (contrast with this post for example, which of the two appears better written and more interesting?)


A few people present that thesis but I haven't found them convincing. I've seen no data indicating that the larger area in practice increases rotational acceleration nor that it increases the probability of ground contact (even though one would expect that it would), but I have seen a couple of studies which (inconclusively) suggested no correlation. There is somewhat better support that the increased mass of the helmet does exacerbate rotation.

Bottom line it doesn't matter though, since the statistical data does show lower levels of injury in accident victims wearing the helmets.

Thank you.

I-Like-To-Bike

Agreed.

FBinNY 

Here, you're almost right in what you infer. take out the word any and it's very close. Besides actually saving a life (at the upper margin) there may also be critical differences possible, both within the band and at the lower margin. Mitigating a serious TBI to a minor one (more than just slightly) would also be a critical difference if we consider the cost and time of care and recovery.

Mind you I'm not using critical to imply any mitigation, but only those which change the character of the event, is from serious life threatening injury with long term damage, to mild injury requiring little or no medical intervention beyond 24hr observation.

Like with the prevention of death, these events happen within a narrow band and are small in percentage compared to all outcomes. Going back to the sodium lines, let's agree that there are two. By analogy, at the high margin, and at the low margin.

wphamilton

Like you I chose the adjectives carefully and the statistical evidence is overwhelming in its consistency and quantity. You can substitute "may" for "usually" if you want, I don't care and it doesn't change the meaning that much. Preventing 85% of the injuries is simply false, there's a pretty good case for preventing and mitigating around 50%, and some present it as low as 10%-15%.

Even accounting for the typical selection bias from hospital/police records, even with the sometimes undesirable methodology and the gaps in data making any universal normalization suspect, there is always a persistent and definite pattern. Mitigate AND, in some cases, prevent injury is the legitimate evaluation when you compare enough head injuries of riders with and without helmets and account well enough for other variables.

meanwhile

Cop. Out.


Wrong:

https://www.cyclehelmets.org/1131.html

time series from countries where helmet wearing increased dramatically because of helmet laws provide the most useful information about helmet wearing (Robinson, 1996). In every case, the large increases in helmet wearing resulted in no noticeable decreases in the percentages of injured cyclists with HI. Perhaps cyclists forced to wear helmets ride more dangerously, and so increase their risk of HI, perhaps helmets are worn incorrectly, or perhaps the benefits of helmets are too small to be detected.

wphamilton

I have to read pages like that with a more critical eye. The section you quote doesn't in fact contradict what I said, even though it may superficially appear to. There are faults there similar to those found in the pro-helmet compilations.

I'm not going to go into it all in detail, but look at the summary sentence following the part you quoted "Either way, it is incorrect to claim that helmets prevent 85% of head and 88% of brain injuries. " They aren't arguing that helmets don't mitigate injuries. They don't make that claim. They're only arguing that the 85% study is wrong, and in part because "Nothing can be concluded from the above data. " (regarding children in this data). This page also makes the same kind of mistake in selection criteria as does the study cited, for example "If we assume the GHC group is typical of children who had bike accidents in Seattle" I'm not going to rehash all of the criticisms of this rebuttal - I'm sure you've seen them already.

Now look at the first sentence you quoted. "From countries where helmet wearing increased dramatically because of helmet laws" with a supporting "cite" to someone's blog page, which furthermore has precisely zero information about which countries this refers to, what the infrastructure is there, what the increase in helmet use was, or the rationale justifying that it is actually "the best information"! Presumably relying heavily on Australia and their much criticized mandatory helmet law.

I've got to tell you, mandatory helmet laws and whatever foreign countries have enacted them have little or nothing to do with the effectiveness of helmets in preventing or mitigating traumatic head injury. It's not the "most useful" information. It's a nice caution against mandatory helmet laws, but for proving anything about the effectiveness of a helmet, completely useless.

meanwhile

And in that what you said was meaningless - that there are "statistics" that back you up BUT YOU WON'T GIVE THEM - this is, in a sense, technically true. Because you said nothing, and nothing can't be negated effectively - it remains nothing.

I'll try to be nice about this: that page is on the 85% study, so they address it. It does NOT mean that what they say ONLY APPLIES TO THE 85% STUDY AND IN NO OTHER CONTEXT! When they say


time series from countries where helmet wearing increased dramatically because of helmet laws provide the most useful information about helmet wearing (Robinson, 1996). In every case, the large increases in helmet wearing resulted in no noticeable decreases in the percentages of injured cyclists with HI. Perhaps cyclists forced to wear helmets ride more dangerously, and so increase their risk of HI, perhaps helmets are worn incorrectly, or perhaps the benefits of helmets are too small to be detected.

...That doesn't somehow magically only apply in the context of the negating the 85% study. It's a fact that applies in all contexts - what with being a fact - and one of its effects is to negate the 85% study.

Anyway: congratulations - I think you've genuinely invented a new form of logical fallacy...

wphamilton

To put it more bluntly, the page you cited isn't worth an argument.

I didn't say that the whole page was only about the 85% quote (although it primarily IS about that, with a few unsupported derivative conclusions thrown in). I said that the section you quote was, and of course it is. That's why you left off the very next line, which explicitly stated it, isn't it? Good grief meanwhile.

I've posted the statistics already, along with links, several times in this thread. I'm not going to do it again, nor go googling up some more. That's just a game you play, "cite your sources", and I frankly don't want to devote any time to it.