« Bike Santa Sleigh Trailer - And Hardside Pannier | Main | Tool Bag Turned into Bike Pannier »

10/12/2011

TrackBack

TrackBack URL for this entry:
http://www.typepad.com/services/trackback/6a0120a7ed5f9d970b014e8c3327c3970d

Listed below are links to weblogs that reference Mountain Biker Vs. Nature:

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

Mike

Cycle helmets aren't particulally effective, and have a negative impact in normal town cycling. There are very few animals in europe's town centres!

For most people cycling without a helmet is safer - http://www.bath.ac.uk/news/articles/releases/overtaking110906.html

Ben

I'm sorry, but you're right! I DO have to chime in.

"a friend of mine was spared his life while wearing one and that is enough science for me"

That seems to show a gross misunderstanding, or contemptuous disregard, of science. An anecdote is not science. An uncontrolled, unreproducible experiment on a single test subject is not science. Science would take a million of "your friend", half with helmets and half without, and subject them to standard bicycling scenarios, and then see which group had more deaths. If you don't do that, your claim is vacuous, and undermines rational thought.

Your "science" is no different from "My friend's life was spared because he was on a steel-frame bike" or "My friend was killed because he was wearing a helmet" or "It's cold in NYC today, therefore global warming is a myth". It doesn't bother me overmuch that you wear a helmet--even though there's plenty of evidence that your wearing a helmet makes my ride more dangerous--but it really bothers me that you endorse unscientific thinking.

Matt

Ben,

Okay Ben, I'm game for a little science. How about me and a friend go out to play a game of catch? In this instance I will hold a small fire arm (I am not familiar with guns but in this instance any will do) and I tell my friend to hold out his hand and catch the bullet that is going to come out of the gun when I pull the trigger. My guess is that 100 times out of 100 he is going to be unsuccessful in catching the bullet because the mass and speed of the flying object (the bullet) is going to be too much for human flesh to stop. I did not major in any sort of hard science but I am guessing this is related to a law of Physics, which I believe is categorized as a "science."

In response to this scenario scientists and engineers came up with something called Kevlar to stop bullets from penetrating the skin of law enforcement officials and members of our armed forces. My guess is that many mathematical formulas and scientific testing was involved in the process of developing Kevlar.

The example above may sound ridiculous, and maybe it is, but so is making light of the fact that my friend perhaps should have been thrown off a cliff multiple times to see if he would have survived.

My friend went off the side of a road and was thrown off his bike into a rocky embankment (comprised of very large rocks). His head, with great force, struck a rock so hard that it shattered his helmet and left him with a major concussion. The doctor said that if he had not been wearing his helmet, even if he had managed to survive, the chances of him remaining alive would have been minimal due to issues like brain swelling and a cracked skull.

So, science for me in this instance was that my friend's head was less dense than the rock that it hit. The helmet was designed, I am sure with a lot of scientific testing, to absorb the force of the blow, transferring energy to the helmet rather than head. In this instance, the helmet performed the function it was scientifically built to do - save someone from critical injury.

Sure I see where you are going with your testing theme and you certainly have merit, but I hope you can now see where I was going with mine, and the merit is in the evidence - my friend walked away with his life.

Peace and Ride Safe, with or without a helmet.

Matt

mykill

"...even though there's plenty of evidence that your wearing a helmet makes my ride more dangerous"

I would like to see some of this evidence.

Steve

If vehicles hitting bikers while overtaking them were the ONLY significant source of injury to bikers, Ben may have a valid point, but, based on that study, he should also be arguing for everyone to have long hair or a wig in order to have the maximum clearance, which I don't see him doing...

Until there are some significant statistics kept comparing helmeted to unhelmeted bicyclists and injuries suffered from all accidents, arguing from a single study only looking at one thing is pretty pointless.

Personally, I'll be wearing a helmet in traffic until such a study is made available proving that it is a bad idea.

None the less, stay safe out there, however you choose to do it.

Bwpearre

Hi Matt,

Thanks for the explanation. I did not mean to give the impression that I was making light of your friend's experience. I'm just dismayed every time I see anecdote held up as a reasonable substitute for science, and it seems to me that this kind of thinking has gotten us into most of the trouble in which we now find ourselves.

Please allow me to elaborate. Our brains tend to make decisions based on anecdote and emotion. We all make mistakes when we interpret evidence (I find the study of the ways in which brains come to incorrect conclusions rather fascinating! Check out "confirmation bias" just as a starting point).

Science is a formal system for asking questions such that we can find answers WITHOUT our emotional biases interfering (ideally!). This leads to higher-quality answers--in particular, ones that even people with very different emotional experience can agree upon.

I'm not "making light" of your friend flying off a cliff. It sounds terrible. But I _am_ saying that using that anecdote as a way of answering the question "Do helmets help?" is unscientific. You're answering that question based on one example and on powerful emotion, both of which are strong indicators that your answer may be unreliable.

So let's look at this question: "Do helmets save lives?" What's wrong with your "all the science I need"?

The first thing is that your sample size is small. So what?

I have a hypothesis that every time I flip a coin it will come up heads. I flip a coin, and it comes up heads. Does that mean I am correct?

How do we fix that? We "take" millions of cyclists, "put" them into lots of situations with and without helmets, and check who survives. This is NOT me making light of anything, and this is NOT me actually forcing cyclists into these situations. Conveniently, cyclists have put themselves into these situations over the past 100 years, with and without helmets. We count up the number of deaths amongst the helmet-wearing and bareheaded populations. So what you get is the large sample size that makes the result more reliable, in the real world, without actually pushing anyone off a cliff.

Your example with the bullet is far from ridiculous--it's perfect. You clearly state your hypothesis, and you propose how to test it. And as with helmets, WE HAVE DATA without actually having to shoot anyone. Humans being what they are, they often do this to each other, and we can go and collect data on how many people caught bullets and how many lost fingers. And your hypothesis turns out to be well-supported by the data--nobody catches bullets without kevlar. So we can say that your hypothesis is verified.

When you do the same thing with bike helmets, you find something unexpected. When cyclists with helmets and cyclists without helmets ride their billions of miles every year, and have their few hundred fatal accidents, those wearing helmets and those not wearing helmets don't actually have significantly different death rates. Now that's pretty strong evidence that the hypothesis, "Bike helmets save lives", is incorrect.

These results have to be carefully controlled, and there's the catch. No experiment really does a perfect job of making sure that they're comparing apples to apples. How do we know how many cyclists wore helmets, or how far they rode? How do we control for other factors, like helmet-wearers being richer and better educated and more careful, or motorists becoming more distracted? "Bike helmets save lives" cannot be absolutely confirmed or falsified for sure, but we can do a pretty good job of controlling these things. Read the literature for some examples. The results aren't clear, but whether bike helmets save lives is certainly still up in the air.

"The doctor said" doesn't really mean very much. The doctor is an expert in what happens to heads being accelerated, but probably knows nothing about how the mechanics of a helmet under that acceleration would deform and thus change the acceleration to which the head is exposed. Doctors have been sold the same hype that cyclists have, and will generally just assume that helmets help.

Did you look at the foam inside the helmet? Was it crushed? If it was split but not crushed, then the helmet didn't do a damn bit of good. If it was crushed, then it did do some good! But the foam in actual accidents often does not crush, but only splits!

"The helmet was designed, I am sure with a lot of scientific testing, to absorb the force of the blow"

That assumption makes as much sense as assuming that the government would make mercury pollution illegal. Should be true, but is actually only a little bit true. May I draw your attention to questions 1, 4, and 5 here? http://www.vehicularcyclist.com/hfaq.html

(It's a quick overview. Let me know if you want more. But the whole FAQ is probably a good starting point.)

So, yes, there's some chance that your friend's helmet helped. There's even some chance that helmets help the cycling population as a whole. But there's as much evidence against the second possibility as for it, and as for the first possibility--we'll (hopefully) never know whether your assumption is correct.

Happy riding!

Bwpearre

mykill:

My claim centers around creating the perception that cycling is more dangerous.

When the number of people on bikes increases, the cycling death rate decreases. This is well-documented, but see, e.g.,

http://www.sciencedaily.com/releases/2008/09/080903112034.htm

Bike helmet laws tend to reduce the number of cyclists and drive up the danger to cyclists:

http://www.grist.org/biking/2011-08-22-helmet-laws-get-in-way-of-bike-sharing-programs
http://www.vehicularcyclist.com/hfaq.html#A14

Less severe, perhaps, than laws, peer groups and cultures create perceptions about cycling. Every helmet-wearing cyclist adds to the perception that cycling is dangerous, and thus decreases the number of cyclists. So everyone who wears a helmet discourages cycling, thus increasing my risk.

Bwpearre

Steve:

The paper to which _you_ allude (I did not) just proposes a _mechanism_ for the observation that helmets kill.

The _observation_ you rightly want proven is that increased helmet use does not reduce the death rate. That turns out to be readily available. See, e.g.:

http://www.cyclehelmets.org/1052.html
http://www.chapmancentral.co.uk/wiki/Helmets_maxi-FAQ

If there weren't so much evidence that helmets don't save lives, the question as to "why?" would never have been asked, and your paper ( http://www.sciencedirect.com/science/article/pii/S0001457506001540 ) would not have been written.

Isaac Garcia

Like I´ve always said, if people don´t think they have anything to protect up there, why should they (or me) worry about protecting it?

And anyway, the whole "wearing a helmet makes it more dangerous" argument is like saying "shoes make it more dangerous to walk, let´s go barefoot" ;)

Ben

Isaac:

"the whole "wearing a helmet makes it more dangerous" argument is like saying "shoes make it more dangerous to walk, let´s go barefoot""

How so?

t.s.

The helmet being "cracked" means its not working vs if it was "crushed" it did argument is not valid. The cracking of the foam is dissipating energy that would otherwise be absorbed by your head. as for the articles detailing why helmets make you less safe, if you wear your helmet wrong of course its not going to work. 2 accident severity and mechanisms in the real world are so chaotic that unless you happend to crash infront of multiple hispeed cameras theres no way it could count as scientific evidence of anything. 3000 helmet wearing people could die in crashes with head injurys and 1 could survive who happend to not be wearing one, and unless you could show that the helmet itself actually increased the actuall damage to the head all these case studies would be meaningless.

in controlled testing which is how helmets get aproved it is veary clearly demonstrated that helmets dissipate energy from impacts.

your helmet is not your magical shield. its just a little tiny extra layer of foam that might make the difference between life and death. you still need to know how to ride your bike.

if your still not convinced go bang your head against a wall a few times with a helmet and a few times without and tell me which you prefer....

but hey its a free country, dont wear a helmet if you dont want to, but ill be fucking pisses if you have the same health insurance company as me.

trek everest

The helmets that we wear on mountain bikes never look effective. I have seen them break with just a small drop. So, I don't think that once you have them on your head you can go about doing anything.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been saved. Comments are moderated and will not appear until approved by the author. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Comments are moderated, and will not appear until the author has approved them.

Loading

Enter your email address:

Delivered by FeedBurner

Cool Stuff

insert title insert title insert title insert title
Blog powered by Typepad
BikeHacks Flickr Pool

Roy Tanck's Flickr Widget requires Flash Player 9 or better.

Get this widget at roytanck.com