Re: Helmet efficacy test

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.

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

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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.
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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.)

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a specious argument with no scientific substantiation.

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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
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- Frank Krygowski