Re: Helmet efficacy test

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

  On Fri, 28 Mar 2025 21:49:52 -0400, Radey Shouman
<shouman@comcast.net> wrote:
 

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.

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

And note the differences, please.
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.
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.
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."
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.
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.
--
- Frank Krygowski