Re: Helmet efficacy test

Radey Shouman <shouman@comcast.net> writes:

Frank Krygowski <frkrygow@sbcglobal.net> writes:
>

On 3/27/2025 2:57 AM, John B. wrote:

On Wed, 26 Mar 2025 23:28:57 -0400, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:
 

On 3/26/2025 3:57 PM, Zen Cycle wrote:

On 3/26/2025 11:47 AM, Frank Krygowski wrote:

>

>

Trouble is, the protection from a bike helmet is far, far less than
people are led to believe. Look up the standardization test.

>
"led to believe" by what metric? I've never seen any literature
claiming a helmet _prevents_ serious head trauma.

>
WHAT???

>
No helmet manufacturer or helmet advocacy group claims helmets _prevent_
serious head trauma. They _can_ reduce severity, not prevent it.

>
Seems to me you're focusing on the difference between "_always_
prevents" (which was never stated by anyone) and "can reduce severity."
The latter is more honest, but is NOT how helmets are promoted. Try
googling "Do bike helmets prevent serious head trauma?" After reading
AI's "Yes" try follow the resulting links.
>
And logically, if a helmet did prevent serious head trauma in one out of
ten cases, that would justify a "Yes" answer. In those cases a helmet
would have done what was asked.
>

Oh, and about helmets mechanically causing injury? Curiosity about
that surged once it became clear that helmeted cyclists seemed to be
over represented in concussion counts.
>
Well, since the helmet certification standard was established
(essentially less than 300gs linear deceleration in a 14 mph
impact), it became known that linear deceleration was far less of a
problem than rotational acceleration. Twisting the head and brain
caused far more brain injury than smacking them. But a helmet
protrudes at least an inch from the head, providing a longer lever
arm for glancing blows, potentially worsening rotational
acceleration. (Note that a bare head's slippery hair and very loose
scalp are probably evolutionary tricks to reduce that hazard. The
helmet makes those ineffective.)

>
a specious argument with no scientific substantiation.

>
What part did you not understand?

>
I understood all of it. What I'm stating is that you have no data to
support the that helmets "provide a longer lever arm and thus can cause
more injury" claim. Every study I've link states the exact opposite.

>
Well, I suppose the "thus" is not totally proven. I don't see how you
can claim they do not provide a longer lever arm for glancing blows. A
helmet absolutely is larger than the head. The radius upon which a
glancing force acts on a helmet is certainly larger than the radius on a
bare head. And BTW, that means that a certain number of misses must be
converted to hits. I hope that's obvious to you.
>
In any case, _something_ seems to be causing a correlation between
rising helmet use and rising cyclist concussions. If it's not the
factors I speculated on, I'd be interested in hearing your theories.
>
See
https://www.cbsnews.com/boston/news/i-team-concussions-on-the-rise-among-cyclists/
>
https://www.slatervecchio.com/blog/bike-helmets-dont-protect-against-concussions/
>
https://www.cbc.ca/news/health/bike-helmets-should-address-concussion-risk-scientists-say-1.1367454

Before you get up to full speed you might want yo to read
https://www.cdc.gov/heads-up/safety/index.html
Which says,in part, "There is no concussion-proof helmet"
Referring, apparently to
  Baseball Helmet -
     Batters Helmet
     Catchers Helmet
     Hockey Helmet
     Hockey Goalie Helmet
     Bike Helmet
     Equestrian Helmet
     Football Helmet
     Lacrosse Helmet
     Skateboard Helmet
     Ski Helmet
     Snowboard Helmet

>
Right. Obviously, any helmet is designed to (hopefully) protect
against impacts of certain type, at a certain intensity. And
obviously, it's possible for impacts to be more severe.
>
Bike helmets come with internal stickers saying something like "No
helmet can protect against all impacts." But the issue I'm raising is
that helmets are portrayed as greatly reducing brain injury, which
should include concussion, the most common brain injury. But national
records of bicyclist concussions show they have risen dramatically,
not fallen, as bike helmets have become ever more common.
>
Flu vaccinations get developed based on predictions of upcoming virus
characteristics. And they are evaluated by after-the-fact reports on
effectiveness, by counts of flu cases and severity in the general
population: How much did this year's vaccine reduce flu infections?
Sometimes the vaccine works really well, sometimes less well.
>
If that same sort of general population evaluation was applied to bike
helmets, the conclusion would be "Yeah, our initial tests looked good,
but they failed in the general population."

>
I doubt you have looked into flu shots with the same energy you have
bike helmets.  Flu shots are a moneymaker, and are promoted every year
regardless of how well they have done.  This is not to say anything
positive or negative about their efficacy, just that it's not relevant
to the decision on whether to promote them.  Same as bike helmets
>
You're an odd case.  Most people who begin to doubt the party line on
one issue begin to see parallels with other issues, and their doubts
multiply.  Bike helmets don't work?  Maybe flu vaccines don't either.
Maybe statins are actually bad for you.  Maybe, as Mr. Shadow tells us,

Of course, I meant to write "Dr. Shadow", would have elevated the whole post.

US standards for blood pressure are counter-productive.  Maybe even
those studies on second hand smoke were nonsense.  Who knows where it
will stop?  Maybe eating saturated animal fat is actually *good* for us.
>
Of course, it's wise not to mention too many heterdox opinions in any
one setting, lest decent people decide you're entirely crazy.  But you
seem quite uncalculating -- It's just bike helmets that are an
unaccountable failure in public health policy, on everything else we
should obey authority.

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