Originally Posted by
350htrr
Yes and I agree the 1% is the risk of having an accident where the helmet failed to protect enough to avoid a hospital visit... But what the actual risk of having an accident where head hits the ground is unknown, totally unknown... That's my point.(trying to be)... So what if the actual chance is 5% but I decide that 1% is safe enough and start to not wear a helmet? A 5% compared to 1% is a big difference, we just don't know the actual % number... We don't have any % numbers where a helmet actually did it's job and shouldn't dismiss that greater possibility...
You suspect a significant number of non-injury traffic accidents, because of the helmet. Well, you can set a reasonable approximate upper bound to that. Assume ALL of the injury accidents were non-helmeted. Helmet use is approximately 19% among adults (includes very casual riders). So if helmets would have protected in every injury and those accidents were equally distributed among helmeted and non-helmeted (reasonable, isn't it?) then there were 5 times as many accidents, and only 1/5 of them recorded as injury. So the maximum injury accident rate would be 5% per year.