7_lives_left wrote:snibgo wrote:What deceleration (and over what time) causes decapitation, or less spectacular death, or irreversible brain damage, or a mild headache? I don't know. Why does the Snell standard specify 300g rather than 200g or 400g? I don't know.
Perhaps the various standards that specify maximum allowed deceleration are based on some research. Or perhaps they are wild guesses.
No they are not wild guesses. Don't know how to put this delicately, but at some point someone will have carried out a test on a cadaver. The results of that test will have been used as a benchmark so that when they do subsequent tests, they don't have to use a cadaver each time. Much more pleasant for the testers that way.
Wikipedia:Crash test dummy-Cadaver testing
Testing a cadaver to see what level of impact causes death or serious brain injury sounds like it would have to be an interpretation based on a set of assumptions and, by definition, not an objective test. Nevertheless the results would be interesting so it would be good to see what they were and how they've been applied to cycle helmet design - is this in the public domain?