Re: Helmet efficacy test

On 3/25/2025 10:24 PM, Frank Krygowski wrote:

On 3/25/2025 5:02 PM, cyclintom wrote:

>
How would you propose that a helmet cause a head injury? You could argue that the foam helmets are heavy and might increase your chances of hitting your head but the Wavecel helmets are light. Helmets don't interfere with vision on a normal road bike.

 There's data out there indicating that people wearing helmets do crash more (and show up in ER more) than people without helmets.

Irrelevant, even if it were true. Statistical analysis on injuries with vs sans helmets take that into account.
(No, it's not

because those without helmets didn't survive, as some have claimed.)
 While not a direct mechanical cause if injuries, some studies - and many, many posted discussion remarks - indicate that people wearing helmets are indulging in "risk compensation" meaning "Hey, I'm wearing a helmet do I can take more risks." (I did that today, but I'll probably wait until tomorrow to post about it.) We've had people post here that they would never do the risky mountain biking they do without the helmet. We've had people say "I would never ride that busy road without a helmet."
 Risk compensation is probably near-universal with lots of "safety" devices. It's not inappropriate as long as the increase in risk is commesurate with the increase in protection.

Again irrelevant. The Moral Hazard argument has a place, but it isn't in the discussion of whether helmets are protective or not.

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.

 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.

 That situation is not fantasy. It is exactly what gave rise to Wavecell and other anti-rotation helmets.

Yes, you finally got something right (in terms of science and data). It's the twisting motion that causes the most damage, but you're still off-base with the 'additional level arm' argument. If that were true, you'd see higher incidents of TBI with helmet wearers. this isn't the case.

But helmet promoters still insist that ordinary helmets are magic.

Complete sensationalism on your part.>

 

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