Originally Posted by
merlinextraligh
I'm having trouble buying that your answer to 1) is truly genuine.
You would grant me that the force your brain gets exposed to in the crash is based on Delta V of your head, the change in Velocity, and Delta T, the time over which that change occurs.
I think you'd also grant me that the crushing of the foam in the helmet elongates the Delta T.
Now you can't know in advance, without mathematical values, for any given impact whether the change in Delta T from the crushing is going to be enough to make a difference in the occurence or severity of an injury, but why wouldn't you want give yourself the benefit of that ride down effect, and the chance that it maight make a difference in a particular accident?
1) The helmet is not designed to provide protection from 28 mph horizontal speeds.
2) The helmet is designed to provide protection from a vertical fall of 5-6 feet.
3) As such, the real benefit of bicycle helmets would be for those walking and or running, do we see people wearing them for the use for which they were designed-no!
4) The process of wearing a helmet increases apparent head size by at least 50%, creating a risk for torsional injuries for which they were not designed and increasing the likelihood of head/helmet contact with the ground. This may be part of the reason for increased injury/death rates in whole population studies.
5) The manufacturers themselves state that helmets will not prevent concussions.
6) The AMA position statement is based upon the terribly flawed data posited by Thompson in 1989 and again in 1996. Once bad data gets into the system it can be devilish difficult to get it removed. For evidence of this read the Bio of Inaz Philipp Semmelwies