Re: Helmet efficacy test

On Sat, 29 Mar 2025 22:16:26 -0400, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:
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On 3/29/2025 8:17 PM, John B. wrote:

On 29 Mar 2025 19:19:26 GMT, Roger Merriman <roger@sarlet.com> wrote:
 

Frank Krygowski <frkrygow@sbcglobal.net> wrote:

On 3/29/2025 12:35 AM, John B. wrote:

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On Fri, 28 Mar 2025 21:49:52 -0400, Radey Shouman
<shouman@comcast.net> wrote:
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Could you point out a few flu vaccine studies, of the design and quality
that would convince you if they were instead about bike helmets?  All of
us have to die of something, congestive heart failure, pneumonia, flu,
whatever.  I guess you would want some evidence that with flu shots
(bike helmets) people actually live longer and better lives.

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Perhaps -
https://www.cdc.gov/flu-vaccines-work/php/effectiveness-studies/index.html
and
https://www.cyclist.co.uk/in-depth/safest-bike-helmet

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And note the differences, please.
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The data on flu vaccine effectiveness comes from counting actual flu
cases in the general population, in some cases among people
hospitalized, in other cases outpatients.
https://www.cdc.gov/flu-vaccines-work/php/vaccine-effectiveness/index.html
So that's counting what actually happened, as in "How many Americans
were infected with flu?" They find that vaccinated folks are much less
likely to catch the flu.
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The helmet article's 3rd photo shows their method of measuring
"effectiveness." It has nothing to do with counting cases in the general
population, as in "How many Americans got TBI while riding?" Instead it
measures deceleration of a model of a human head (no body attached)
that's dropped onto an anvil.
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If they evaluated helmets as they do flu vaccines, they'd have to say
"Hmm. Looks like no evidence for saving lives, but concussions have gone
up."
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Also notice the article gives no specific data on the test. The impact
speed is 14 mph (from a 2 meter drop) and the deceleration is required
to be less than 300 gees to pass government certification.
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And if you have an expensive, very lightweight helmet you can be sure
that the designers whittled away styrofoam as much as possible, leaving
enough to just barely pass that impact test.
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There are other folks doing testing, and cheap helmets still don’t do well,
more expensive helmets have MIPs and other similar tech ie stuff that is
intended to protect from rotating injuries. Or in the MTB world heavier
burlier full face ones.
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I can’t imagine is any population data either way but I’d absolutely not
assume cheap would be stronger, is an unwise assumption.
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Roger Merriman

 
 
O.K. Try https://www.nature.com/articles/s41598-023-35728-x

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What was your point, John? I ask because it seems you just grabbed
another study at random. Roger's and my discussion was about cheap
helmets vs. expensive ones. I didn't see that addressed. Perhaps when
you post a link, you could tell us what part of the study was
significant to our discussions?
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I did see this: "Although rotational acceleration has been known to be
relevant in cyclist injuries, it is still missing in standardized
testing today. Using full body simulation, Wang et al.24 confirmed that
rotational acceleration is indeed increased when wearing a helmet." That
would seem to go back to the issue of a larger moment arm for glancing
blows.
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And that paper, like almost all, does almost nothing to address the lack
of reduction in TBI counts in the entire population. They do mention one
paper by Olivier claiming large reductions in cyclist TBI in Australia
after their mandatory helmet laws (MHLs). But Olivier is famous in other
forums for his insistence that there was no reduction in cycling as a
result of the MHLs. Copious survey and count data indicating large
reductions in cycling, which would of course lead to large reductions in
cyclist TBI.
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In Olivier's world, prohibiting all cycling would be a great way of
wiping out almost all cyclist TBI.

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Sorry Frank, I hate to be the one to tell you but the world does
rotate around you.
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What actually happened was that Radey Shouman asked a question and I
replied to it with two references. And subsequently with a third..
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Then you leap into the fray.
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Note that I wasn't talking to you and as far as I can tell neither was
Giouman.
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But here you were blathering away.