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  1. #3201
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    I'm looking forward to a nice 60-70 mile ride down to Cape May from Ocean City, NJ tomorrow morning. Should get to see the sunrise as well as lots of miles of ocean as I make my way down the coast. Hopefully everyone else's rides are as enjoyable, and safe of course

  2. #3202
    Senior Member closetbiker's Avatar
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    I'm heading back to London this afternoon.

    Hopefully, I'll have my camera ready for all that "civilized" traffic.

  3. #3203
    Senior Member rugerben's Avatar
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    I ALWAYS wear my helmet, and i have taught my best friend's dog to do the same. She'll never ride her Schwinn Alloy-7 without a helmet. See?

    Last edited by rugerben; 09-04-08 at 09:22 AM.
    MOLON LABE

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    Helmets cramp my style

    My wife and I are in our 50s and have been riding road bikes for two years now. If we had not been wearing our helmets, I hate to think of the mental condition we would be in today. In seperate accidents at seperate times, we have both fallen and landed on our heads. She had a mild concusion as a result of hers. My helmet was severely cracked in multiple places. I hate to think of how my head would have fared from my accident if I had not been wearing my helmet. In both of our wrecks, we were not going very fast (around 12 mph) but the events happened so fast we could not have stopped our heads from hitting the pavement.

    Bill

  5. #3205
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  6. #3206
    Senior Member closetbiker's Avatar
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  7. #3207
    Senior Member John C. Ratliff's Avatar
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    This is also a source quoted by Closetbiker on different topics. Here is one quote from this source:

    Quote Originally Posted by Bicycle Helmet Safety Institute
    A very high percentage of cyclists' brain injuries can be prevented by a helmet, estimated at anywhere from 45 to 88 per cent.
    Here's the link:

    http://www.helmets.org/stats.htm

    John
    John Ratliff

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    Let me throw my 2 cents worth in. Three weeks ago I was in a crash. Hit the road at about 30 mph.
    As I was being life flighted, reports were severe hip/leg damage and probable severe head trauma based on the appearance of the helmet and the fact that I was somewhere else. MY femur was broke and shattered. I now have a titanium rod from hip to knee. As far as the head goes, I'm fine. The helmet split, cracked and compressed, but did its job. Doctors said I should never come out as good as I did. I always wore a helmet before and will never on on a bike again without one.

  9. #3209
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    The two things that posters don't seem to get re. personal anecdote is that

    A) It's impossible to know the outcome of any given crash if a helmet had not been worn -- and no one can extrapolate potential brain injuries from the condition of crashed helmet.

    B) Personal anecdote is no more or less valid than someone else's personal anecdote. For instance, I've never suffered a head injury despite a long history of riding and racing without a helmet, but that certainly doesn't mean that helmets are completely useless.

  10. #3210
    Senior Member closetbiker's Avatar
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    Quote Originally Posted by John C. Ratliff View Post
    This is also a source quoted by Closetbiker on different topics. Here is one quote from this source:

    A very high percentage of cyclists' brain injuries can be prevented by a helmet, estimated at anywhere from 45 to 88 per cent.

    Here's the link:

    http://www.helmets.org/stats.htm

    John
    from bicyclesafe.com http://bicyclesafe.com/helmets.html

    Most of us have heard that "bicycle helmets can prevent up to 85% of head injuries". Many times the phrase is printed without the "up to", stating flatly that bike helmets "prevent 85% of head injuries". Typically, no source is ever cited for this 85% figure. Everyone believes it anyway, so who needs a source, right? But where did this 85% figure come from, and is it credible? The answer is that it came from a flawed 1989 study, and it's probably wildly inaccurate. The study was roundly criticized in the Helmet FAQ by the Ontario Coalition for Better Cycling and by CycleHelmets.org, which states:

    This paper is by far the most frequently cited research paper in support of the promotion of cycle helmets. It is referred to by most other papers on helmets, to the extent that some other papers, and most helmet promotion policies, rely fundamentally upon the validity of its conclusions.
    The claims that helmets reduce head injuries by 85% and brain injuries by 88% come only from this source, yet are quoted widely as gospel by people who know nothing more about cycle helmets. The prospect of achieving such massive reductions in injuries to cyclists lies at the root of helmet promotion and mandatory helmet laws around the world.

    Those who have taken the trouble to analyse the paper in detail, however, have found it to be seriously flawed and its conclusions untenable.

    more...http://www.cyclehelmets.org/1068.html

    They also note that not a single helmeted cyclist considered in the study was involved a collision with a motor vehicle, yet virtually all brain injured victims were the result of motorist/cyclist collisions

    and from http://www.chapmancentral.co.uk/wiki..._helmet_debate

    I am not anti-helmet, I am a former helmet advocate who has become sceptical in response to the evidence. Nonetheless I don't doubt that I will have missed out some factors which fail my personal cultural filters, so I encourage you do your own research and think for yourself....A good litmus test of any helmet site is: if they uncritically quote 85% effectiveness, engage suspicion mode immediately ...a balanced view means looking at both sides, then making up your mind...that the mean point in this debate is not between scepticism and zealotry, it's not even between those who advocate laws banning helmet use (if any such exist) and those who advocate compulsion - beware the fallacy of the false middle. The default in the scientific method is for those who advocate an intervention, to bear the burden of evidence, and to explain away any conflicting evidence, but helmet advocates seem to consistently fail to recognise the null hypothesis with the result that they fall into several of the traps inherent in observational studies
    Last edited by closetbiker; 05-30-08 at 04:09 AM.

  11. #3211
    Senior Member closetbiker's Avatar
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    Quote Originally Posted by Six jours View Post
    ...

    B) Personal anecdote is no more or less valid than someone else's personal anecdote. For instance, I've never suffered a head injury despite a long history of riding and racing without a helmet, but that certainly doesn't mean that helmets are completely useless.
    Indeed, and what I also don't get is how this is looked at in perspective. Helmets have only been used for a short time, yet people have been riding bikes for a long time. How is it that we managed to survive all those years without them?

    I've used a helmet for 20 years, yet I also went without for 20 years. I've fallen plenty without one and was fine. Bought one because I thought it would save me from brain damage then I found out the limitations of them. I was very disappointed. It's no surprise to read in the paper, yet another helmeted cyclist killed.

    Irony abounds in some news releases

    Quote Originally Posted by ChalotteObserver

    HELMET CAMPAIGNER KILLED ON BIKE - A female cyclist from Charlotte, North Carolina and an advocate of bicycle helmets died with another cyclist when they were hit by an SUV on October 21 . The cyclist, Lee Anne Barry, who had suffered a brain injury as a child had become an activist for brain injury victims, having since 2001 regularly cycled across the US to raise awareness of the disability. She frequently appeared before audiences of school children, urging them to wear bicycle helmets using as props the battered headgear of people who had been involved in accidents.
    Last edited by closetbiker; 05-30-08 at 10:52 AM.

  12. #3212
    Senior Member rollerdavem's Avatar
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    Wow. This is really a hotly contended issue!

    There are some pretty good points made on both sides, and I think that helmets probably have their benefits AND drawbacks like anything else in life.

    Where I come down on this is: I don't believe this is a black and white moral issue, or that anyone should be compelled against their will to act in what others see as their best interests.

    I'll trust you enough to decide for yourself what is safe for you in any given circumstance and won't judge you if you if the same facts I have reviewed lead you to a different opinion than I hold.

    I'll respect your right to do what you think right and proper.

    I thank you for your concern, and for caring about my safety, only a fool would object to people caring about them, but I'll thank you to remember that I have considered both sides and am capable of deciding for myself and ask you to accord me the same respect I extend you.

    Are there times I will choose to wear my shiny new helmet? Absolutely.
    Are there times I will choose not to? Without a doubt.

    Is it my right and business to decide? Indisputably.

    Do I wish to discuss it or be subjected to any further well intentioned peer pressure or 'encouragement?'

    Nope.

    So, While wishing everyone the most safe and enjoyable biking experience their circumstances and choices can create, I will simply chalk up any further helmet-related comments directed towards me as well intended, and move on without any comment of my own.

    After all, even though we may not see things perfectly the same, we are all here talking about riding, which we all love; we have more in common than not.

    And in my opinion, THAT'S what really matters, not making value-judgments on another's choices and opinions. Some of the sniping and belittling I have read in this thread from proponents on BOTH sides really saddens me.

    Having considered all of it, and resolved to make up my own mind, I will add no further fuel to this fire.

    Thank you all for your concern and opinions,

    RD
    "It's NEVER too late to do the Right Thing. Oh, and while you're up I'll have a cup of coffee, thanks." -- Rollerdave

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  13. #3213
    Senior Member John C. Ratliff's Avatar
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    Quote Originally Posted by bigdog51 View Post
    Let me throw my 2 cents worth in. Three weeks ago I was in a crash. Hit the road at about 30 mph.
    As I was being life flighted, reports were severe hip/leg damage and probable severe head trauma based on the appearance of the helmet and the fact that I was somewhere else. MY femur was broke and shattered. I now have a titanium rod from hip to knee. As far as the head goes, I'm fine. The helmet split, cracked and compressed, but did its job. Doctors said I should never come out as good as I did. I always wore a helmet before and will never on on a bike again without one.
    Quote Originally Posted by Six Jours
    The two things that posters don't seem to get re. personal anecdote is that

    A) It's impossible to know the outcome of any given crash if a helmet had not been worn -- and no one can extrapolate potential brain injuries from the condition of crashed helmet.

    B) Personal anecdote is no more or less valid than someone else's personal anecdote. For instance, I've never suffered a head injury despite a long history of riding and racing without a helmet, but that certainly doesn't mean that helmets are completely useless.
    Six Jours,

    The two things that you don't seem to get re. "personal anecdote" is that:

    A) What is a "personal anecdote" to one person is an unpublished case study to another. The validity comes from knowing the exact circumstances, medical history, condition of the helmet, circumstances of the ride and crash, etc., which makes this a valid case study to those involved. Whether it translates to others depends upon how it is presented. If this was presented as above, then there is a lack of details which would makes someone skeptical; if it were presented in the New England Journal of Medicine by his trauma physician as a case study, then it would be accepted by many doctors (but probably not by you, judging from your responses here). Here are examples of case studies:
    1: Brain Nerve. 2007 Dec;59(12):1369-72.Links
    [Rapid disappearance of acute epidural hematoma by percutaneous aspiration of subperiosteal hematoma--case report]
    [Article in Japanese]

    Kino****a Y, Tsuru E, Kasuga U, Yasukouchi H, Harada A, Okudera T.

    Department of Neurosurgery, Munakata Suikokai General Hospital, 341-1 Kamisaigo, Fukutsu, Fukuoka 811-3298, Japan.

    We present the case of an 8-year-old boy who was injured in a bicycle accident and was admitted with a right frontal skull fracture, an acute epidural hematoma, a right frontal laceration, and a subperiosteal hematoma on admission. After the frontal cutaneous suture, the subperiosteal hematoma was aspirated by the percutaneous needle. Two hours later, a CT scan revealed that the epidural hematoma was disappeared. It is speculated that the subperiosteal and epidural hematoma communicated via the skull fracture thus necessitating the evacuation of the epidural hematoma by subperiosteal aspiration.
    From the description, this child did not have a helmet on. Here's another case study:
    1: Neurol Med Chir (Tokyo). 2004 Nov;44(11):584-6.Click here to read Links
    Acute epidural hematoma caused by contrecoup head injury--case report.
    Mitsuyama T, Ide M, Kawamura H.

    Department of Neurosurgery, Tokyo Women's Medical University Daini Hospital, Tokyo, Japan. michan@pop16.odn.ne.jp

    A 50-year-old woman presented with a rare case of contrecoup epidural hematoma (EDH) associated with coup EDH. She was hit by a car while riding a bicycle, and struck the left parietal region of her head on the ground. She was dazed for a few minutes. On admission, she complained of nausea but exhibited no neurological deficits. Skull radiography revealed a linear fracture of the left temporal bone. Computed tomography (CT) demonstrated acute EDH in the right frontal region due to contrecoup injury, and thin EDH in the left temporal region due to coup injury. She vomited repeatedly after admission. She became lethargic and exhibited right hemiparesis. CT, taken 2 hours later, revealed enlargement of the left coup EDH, but no enlargement of the right contrecoup EDH. An emergent evacuation of the enlarged coup EDH was performed. Immediately after the operation, she became alert and the right hemiparesis subsided. The contrecoup EDH was conservatively treated, in the absence of enlargement. She was discharged 12 days after the injury without neurological deficits.
    This case study shows that an injury to an unprotected head can result in both coup (at the site of the injury) and contrecoup (on the opposite side of the brain) injury, in this case bleeding.

    B) Your experience has nothing to do with someone else's experience. When I say that "I'm tired," to my wife, she sometimes says "I got up earlier than you did..." implying that since she wasn't tired, I should not be too. But we are different people, with different physiology, ages, sexes, etc. What she is experiencing has nothing to do with what I am experiencing. The same applies to you and bigdog. His experiences are far different from yours, which I think is what you are actually saying, but the post implies another interpretation. By the way, from what you describe Six Jours, you have never hit your head on the pavement. That was true for me for over 30 years too.

    Those of you who feel that personal anecdote have no place in these pages should also know that for that person, they are very real, and as I said above, more of a "case study" than an anacdote.

    John
    John Ratliff

  14. #3214
    Senior Member John C. Ratliff's Avatar
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    Quote Originally Posted by closetbiker View Post
    Indeed, and what I also don't get is how this is looked at in perspective. Helmets have only been used for a short time, yet people have been riding bikes for a long time. How is it that we managed to survive all those years without them?

    I've used a helmet for 20 years, yet I also went without for 20 years. I've fallen plenty without one and was fine. Bought one because I thought it would save me from brain damage then I found out the limitations of them. I was very disappointed. It's no surprise to read in the paper, yet another helmeted cyclist killed.

    Irony abounds in some news releases
    Quote Originally Posted by [B
    Charlott Observer[/B]]

    HELMET CAMPAIGNER KILLED ON BIKE - A female cyclist from Charlotte, North Carolina and an advocate of bicycle helmets died with another cyclist when they were hit by an SUV on October 21 . The cyclist, Lee Anne Barry, who had suffered a brain injury as a child had become an activist for brain injury victims, having since 2001 regularly cycled across the US to raise awareness of the disability. She frequently appeared before audiences of school children, urging them to wear bicycle helmets using as props the battered headgear of people who had been involved in accidents.
    Interesting--this article says nothing about the cause of death. The fact that two cyclists were killed by one SUV tends to indicate a head-on accident, with multiple injuries. Yes, a helmet will not protect one from this situation, just as a helmet will not protect a sky diver if his/her parachute fails to open. But if that sky diver has a malfunction, has to come down on the reserve chute into a rocky area, then the helmet will be of some use. Similarly, a bicycle helmet will not help someone being hit head-on by an SUV, or a Mack Truck (as I've stated before). But it will be of use in an auto accident if the blow is grazing, knocking someone off to the side, and into a rocky ditch. This just happened to a pedestrian here in the Portland, OR area, and the pedestrian was killed. But the driver was not cited as he had stopped, could not find anything, and thought he had hit an animal. His victim was in a ditch, out of view, and died of head injuries...not from the vehicle but from hitting her head on rocks or some other hard object when she fell into the ditch.

    http://www.oregonlive.com/metrowest/...280.xml&coll=7

    John
    Last edited by John C. Ratliff; 06-01-08 at 01:00 AM. Reason: add link; correct sentence structure
    John Ratliff

  15. #3215
    Senior Member closetbiker's Avatar
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    Basically, you're saying a helmet works, except when it doesn't. You're not examining what it was that exceeded the helmets protective qualities because you don't know what the circumstances were. You're also ignoring what happens when people have put on helmets and continued to die at the same rate as when they didn't wear helmets. I'd say you're looking at the issue with rose colored glasses.

    You're willing to accept there are limitations to a helmets protection, but just won't admit they are made to protect without third party involvement or a speed in excess of the limitations set forth in the specs. You're willing to accept the helmet softens a blow when a helmet has a simple, direct fall to the ground but unwilling to accept in addition to this downward momentum in a fall, there is also forward momentum in the fall and most probably in addition, a change in direction from a collision adding a third force complicating the falls impact. The perameters of a helmets specs are not often found in a typical cyclist collision.

    I know you know there are very few deaths involving falls or collisions with motor vehicles with cyclists and that most falls with collisions between motor vehicles and cyclists without helmets do not result in deaths or injuries so how can you be so sure it was a helmet that "saved a life" of a helmeted cyclist when there are collisions between a motor vehicle and a helmet less cyclist where the cyclist did not die?
    Last edited by closetbiker; 06-01-08 at 04:55 AM.
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  16. #3216
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    Whether you call it "personal anecdote" or "case study" or whatever, the simple fact is that you cannot know that outcome of a helmetless crash had the person been wearing a helmet, nor the outcome of a helmeted crash had the person been bare-headed. We do know that it's human nature to look at a damaged helmet and say to ourselves "My helmet saved my life!" but again, if helmets really did save lives that often we'd see it in the statistics. Not to mention the oft-repeated point that we did not see constant and overwhelming carnage in the pre-helmet days.

  17. #3217
    Senior Member John C. Ratliff's Avatar
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    Quote Originally Posted by closetbiker View Post
    Basically, you're saying a helmet works, except when it doesn't. You're not examining what it was that exceeded the helmets protective qualities because you don't know what the circumstances were. You're also ignoring what happens when people have put on helmets and continued to die at the same rate as when they didn't wear helmets. I'd say you're looking at the issue with rose colored glasses...
    No, there are no rose-colored glasses here. If you become a hood ornament of a vehicle going the other direction at 55 mph, you die, simple as that, helmet or no helmet. If you manage to elude that vehicle, and in the process crash into something, the helmet will have preventive injury value. So far as "ignoring what happens..." above, realize that there are a number of statistics out there, and it seems to my that your are "creaming" those stats (getting only those you want, to you who have never picked strawberries and seen people "cream" the row by picking only the cream of the crop). By the way, the link:

    http://www.helmets.org/stats.htm

    seems to have stats which counter what you say.

    Quote Originally Posted by closetbiker View Post
    ...You're willing to accept there are limitations to a helmets protection, but just won't admit they are made to protect without third party involvement or a speed in excess of the limitations set forth in the specs. You're willing to accept the helmet softens a blow when a helmet has a simple, direct fall to the ground but unwilling to accept in addition to this downward momentum in a fall, there is also forward momentum in the fall and most probably in addition, a change in direction from a collision adding a third force complicating the falls impact. The perameters of a helmets specs are not often found in a typical cyclist collision...
    No, again I fully know the limitations, but I also will say that if you are involved in one of those "out-of-spec" collisions, you will still be better off with a helmet than without. So far as the forward momentum, we covered this about two years ago in detail with force diagrams, etc. If the forward momentum stops cold, you're dead, simple as that. Running headon into a bridge abutment will do that. But striking a glancing blow to the pavement, where forward velocity is slowed but not stopped, may well be within the 200 g's that the brain can withstand. The two force vectors (vertical and horizontal) are independent factors. So far as the change of direction from the collision, and a twisting component, you are better off with a slick plastic coating on a helmet than with flesh contacting the ground.

    Quote Originally Posted by closetbiker View Post
    ...I know you know there are very few deaths involving falls or collisions with motor vehicles with cyclists and that most falls with collisions between motor vehicles and cyclists without helmets do not result in deaths or injuries so how can you be so sure it was a helmet that "saved a life" of a helmeted cyclist when there are collisions between a motor vehicle and a helmet less cyclist where the cyclist did not die?
    Would you mind rephrasing this sentence. It is a run-on sentence with 76 words and a question in there someplace, but I cannot figure out what you are asking. So what is it? I just gave two examples where helmetless cyclists had brain injuries (the case studies above). The link above has many stats about cycling injuries. So what are you asking? Here's one of the stats from the Insurance Institute for Highway Safety 2006 report from that link:

    Deaths among bicyclists younger than 16 have gone down by 84 percent since 1975, while deaths among bicyclists 16 and older have more than doubled.
    Could this be because of mandatory helmet laws for those under 16?

    John
    Last edited by John C. Ratliff; 06-02-08 at 11:24 PM. Reason: Add quote, add date.
    John Ratliff

  18. #3218
    Senior Member John C. Ratliff's Avatar
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    Quote Originally Posted by Six jours View Post
    Whether you call it "personal anecdote" or "case study" or whatever, the simple fact is that you cannot know that outcome of a helmetless crash had the person been wearing a helmet, nor the outcome of a helmeted crash had the person been bare-headed. We do know that it's human nature to look at a damaged helmet and say to ourselves "My helmet saved my life!" but again, if helmets really did save lives that often we'd see it in the statistics. Not to mention the oft-repeated point that we did not see constant and overwhelming carnage in the pre-helmet days.
    If what you say here were really true, you have just invalidated the scientific method. Conclusions can be drawn based upon evidence provided by simulation. If a helmet does keep a person's head from experiencing over 300 G's acceleration or deceleration, according to the test protocols and medical evidence, acute brain injuries will be minimized. Here is the Snell B-95A standards for their tests:

    E4.3 Test Impacts

    Each sample will be subjected to no more than four test impacts. Test impact sites shall be on or above the test line. Rivets, vents and any other helmet feature within this region shall be valid test sites. Similarly, no allowance shall be made for the cut of the helmet either between the fore and rear planes or at the rear centerline; no matter how closely the edge of the helmet encroaches on the test line. However, if a test impact is sited closer than 120 mm to any previous test impact site on that sample, that impact shall be declared invalid.

    There is no restriction regarding test anvil selection except that each anvil shall be used at least once for each helmet sample tested. The impact energies for each test impact are as follows:

    a. For each impact against the flat anvil, the impact energy shall be 110 J for certification testing and 100 J for all other testing regardless of headform size or weight. Given an ideal frictionless mechanical test facility, this impact energy represents a 2.2+ meter drop of a 5 kg headform and supporting assembly.

    b. For each impact against the hemispherical anvil, the impact energy shall be 72 J for certification testing and 65 J for all other testing regardless of headform size or weight. Given an ideal frictionless mechanical test facility, this impact energy represents a 1.3+ meter drop of a 5 kg headform and supporting assembly.

    c. For each impact against the kerbstone anvil, the impact energy shall be 72 J for certification testing and 65 J for all other testing regardless of headform size or weight. Given an ideal frictionless mechanical test facility, this impact energy represents a 1.3+ meter drop of a 5 kg headform and supporting assembly.

    d. If the impact energy for any test impact exceeds the energy specified by more than 3%, that impact shall be declared invalid.
    http://www.smf.org/standards/b/b95std.html
    If the head is kept within these standards by the helmet, and there is no penetrating injury (from a rod or something), you can pretty well predict that the result will be very little potential for permanent brain damage. Forensics can be used to look at damaged helmets and determine the forces involved.

    John
    John Ratliff

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    Quote Originally Posted by E4.3 Test Impacts, provided by John C. Ratliff
    this impact energy represents a 2.2+ meter drop of a 5 kg headform and supporting assembly
    I have a question about this test and John's approval of this simulation. How does one fall and hit the top of their head and only have the weight of their head included in the impact force? If I'm flopping over on my side such that the weight of my body is supported by the ground (and not included in the impact force of my head) it's the side of my head (the basically unprotected part) that's hitting the ground.

    I don't want to sound completely skeptical but it sounds as though this test for impact protection is quite unrealistic and geared more towards allowing helmets to pass the test than it is towards providing actual protection for the crash victim. I say this because it would be quite tough to design a helmet to protect against the full weight of a person crashing down but much easer if you only consider the weight of their head (less than 10% of the weight of even a very light adult cyclist)

  20. #3220
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    Quote Originally Posted by John C. Ratliff View Post
    If what you say here were really true, you have just invalidated the scientific method.
    Right. Because we all know that "scientific method" really just means an uncontrolled experiment done one time with the results being whatever the observer wants them to be.


    Quote Originally Posted by John C. Ratliff View Post
    If the head is kept within these standards by the helmet, and there is no penetrating injury (from a rod or something), you can pretty well predict that the result will be very little potential for permanent brain damage. Forensics can be used to look at damaged helmets and determine the forces involved.
    "Forensics" might be able to "look at damaged helmets and determine the forces involved", though I doubt it. But the average doctor/nurse/paramedic -- let alone Joe Bloggs posting to the internet about how his helmet has saved his life a half dozen times -- is not trained in forensics.

    So if we distill your post down to its essence, you are arguing that falling off of a bike is a scientific experiment and that looking at a crashed helmet is forensic investigation.

  21. #3221
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    The point has already been made that helmet performance 'simulations' bear almost no relation to actual cycling crash incidents.

    Furthermore, evidence does exist that shows that 'soft shell' helmets increase the likelihood of rotational forces being aplied top the head, which are a significant cause of brain injury. No element of rotational force is tested in current helmet standards.

    Imagine if the efficacy of airbags was determined by dropping a 5kg headform onto them on a workbench. I doubt it would give you much confidence that they were any use in a crash. For this reason the 'simulations' used in car crash testing involves crashing actual cars.

    In principle it would be quite straightfoward to do the same kind of testing for helmets - put one on a crash-text dummy, put the dummy on a bike rig, and then smash it into things at various speeds / angles to simluate actual cycle crashes. To the best of my knowledge, no-one has ever attempted this.

    To use a single incident (whether or not we dignify anecdotes with tbe 'case study' moniker) to derive a position is extremely hazardous, and virtually unsupportable in statistical terms. Conversely, the largest data available is likely to be the most accurate in representing actuality.

    The largest data are those pertaining to countries, states and cities that have introduced MHL. These are quite good data, in that they are less likely to exhibit (although not immune from) errors due to exposure controls. It is interesting that it has never been shown that MHL lowers the incidence of injuries to cyclists.

  22. #3222
    Senior Member John C. Ratliff's Avatar
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    Quote Originally Posted by trombone View Post
    The point has already been made that helmet performance 'simulations' bear almost no relation to actual cycling crash incidents...

    ...The largest data are those pertaining to countries, states and cities that have introduced MHL. These are quite good data, in that they are less likely to exhibit (although not immune from) errors due to exposure controls. It is interesting that it has never been shown that MHL lowers the incidence of injuries to cyclists. (emphasis added, jcr)
    Well, it has never been shown, right? You will probably have problems with this study too:
    1: J Trauma Nurs. 2007 Apr-Jun;14(2):84-7.Click here to read Links
    The effect of bicycle helmet legislation on pediatric injury.
    Pardi LA, King BP, Salemi G, Salvator AE.

    Akron Children's Hospital, Ohio 44308-1062, USA. lpardi@chmca.org

    BACKGROUND: Research supports the use of a correctly fitted bicycle helmet to reduce the risk of bicycle-related head injury. Although parents believe bicycle helmets work, a large percentage of children do not wear helmets while riding. PURPOSE: The purpose of this study was to track pediatric bicycle-related injuries presenting to a pediatric trauma center 1 year before and 5 years after 2001 bicycle helmet legislation aimed to protect children 0 to 16 years. METHODS: Prospective data collection of pedal cycle injury e-code 826.1 from hospital discharge data set from January 1, 2000, through December 31, 2005. Bicycle-related injuries among children 0 to 16 years were grouped by injury type (head, extremity, and other), age, and gender. RESULTS: For years reviewed (2000-2005), bicycle-related injuries were highest in the period May through August. Bicycle-related injury rates per 100,000 for this population were 1,452 a year before legislation. The injury rate decreased 27% (1,054/100,000) one year later. Overall, bicycle-related injury per 100,000 continues to be down by 24%. Data show that extremity injury is greater than head and other injury categories in both male (24% greater) and female (27% greater) children 0 to 16 years one year before legislation. Data show extremity injury rates per 100,000 is greater than head and other injury categories in both male (24% greater) and female (38% greater) categories 5 years later. Bicycle-related injury rates per 100,000 in boys were greater than girls for all years reported. Male extremity injury was 45% higher for 10- to 16-year-old boys than for 5- to 9-year-old boys a year before legislation and continued to rise to 58% in 2005. Male head injury rates per 100,000 were higher in 5- to 9-year-old boys (598/100,000) than in 10- to 16- year-old boys (354/100,000) one year before legislation. In 2005, the bicycle-related head injury rates per 100,000 dropped to 485 for 5- to 9-year-old vs 223 for the 10- to 16-year-old boys. Female extremity injury rate per 100,000 for 5- to 9-year-old girls in 2000 was 367, exceeding the 10- to 16-year category rate of 213 per 100,000. In 2005, female extremity injury per 100,000 was 299 for the 5- to 9-year-old girls and rose 16% to 250 for 10- to 16-year-old girls. Head injury rates per 100,000 for 5- to 9-year-old girls in 2000 were 325, ending with a rate of 254 per 100,000 in 2005. Head injury rates per 100,000 for 10- to 16-year-old girls in 2000 were 93, ending in 2005 with a rate of 91 per 100,000. CONCLUSION: The greatest reduction in injury occurred 1 year after legislation, suggesting that promoting bicycle helmet use in the community is effective in reducing injury. The overall rate of bicycle-related injury in the population studied continues to be down 24%, suggesting bicycle helmet legislation for children is an effective adjunct in reducing injury. Extremity injury rates were greater than head injury in both male and female populations, suggesting that future bicycle safety initiatives address extremity injury. Female head injury rates in the 10- to 16-year-old population changed very little from baseline and would benefit from further investigation of female riding habits and perceived barriers to bicycle helmet use.
    John
    John Ratliff

  23. #3223
    Senior Member John C. Ratliff's Avatar
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    Quote Originally Posted by joejack951 View Post
    I have a question about this test and John's approval of this simulation. How does one fall and hit the top of their head and only have the weight of their head included in the impact force? If I'm flopping over on my side such that the weight of my body is supported by the ground (and not included in the impact force of my head) it's the side of my head (the basically unprotected part) that's hitting the ground.

    I don't want to sound completely skeptical but it sounds as though this test for impact protection is quite unrealistic and geared more towards allowing helmets to pass the test than it is towards providing actual protection for the crash victim. I say this because it would be quite tough to design a helmet to protect against the full weight of a person crashing down but much easer if you only consider the weight of their head (less than 10% of the weight of even a very light adult cyclist)
    According to Closetbiker, a bicyclist rarely hits on the top of his head. If that logic is followed, then the rest of the body will impact the ground before and at the same time as the head, taking the momentum off the head and helmet. That's what happened to me, most likely, as I had a pretty good shoulder injury with my last big fall. 'Just a thought...of course, Closetbiker could also be wrong, and you would have a better point.

    John
    John Ratliff

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    The trouble with most (all) of these studies is they don't do a full study of number and type of riders before and after these laws. They say 'per 100,000' but they mean general population not number of bicycle riders. If the number of riders drop because they refuse to wear helmets or become afraid because they are told bicycling is a terrible risk (which is the implication), the number of accidents should go down too. These studies are very poorly done.
    I wear a helmet and I am against helmet laws.

  25. #3225
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    Quote Originally Posted by John C. Ratliff View Post
    According to Closetbiker, ... Closetbiker ... blah blah blah
    John
    Show me a helmet manufacturer that claims their bicycle helmet provides adequate protection for a cyclist in a collision with a motor vehicle.

    (and keep away from making this personal. Address the issue. If you want to address an argument, do it on the arguments merits. If you don't, it's not debate, it's a personal issue - but then again, I do think I know where you're coming from. Every time I see, "John C. Ratliff" in the reply, I tend to think, "this guys views are nuts" and dismiss the post even before I read it. But the I do read it and find, yup, this guys views are nuts.)

    also, I'm back from London. Took a side trip to Oxford. Good to see some people are bright in this world and haven't fallen for the "helmet hype"

    Here's a pic of some not partaking in excess PPE



    Arguments that appear to disavow the efficacy or utility of cycle helmet wearing, or on the other hand claim it as the major influence in reducing injury to cyclists, are both wide of the mark. In particular, campaigns seeking to present cycling as an inevitably dangerous or hazardous activity, or which suggest that helmet wearing should be made compulsory, risk prejudicing the delivery of those very benefits to health and environment which cycling can deliver: they also serve to confuse the general public about the wider social and economic advantages of cycling. As a result, the NCS Board is anxious that the question of wearing helmets is placed in its proper context.

    National Cycling Strategy Board – Statement Of Policy: Cycle Helmet Wearing January 2004
    Last edited by closetbiker; 06-02-08 at 05:44 PM.
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