Originally Posted by chasm54

[Curnow, W.J., 2005. The Cochrane Collaboration and bicycle helmets. Accid. Anal. Prev. 37, 569–573] In that paper Curnow points out that the Cochrane analysis of helmet effectiveness is flawed because helmets will not protect against brain injury caused by oblique impacts giving rise to angular acceleration. Other commentators have suggested that it may be worse than that, because the vents on modern helmets may have a tendency to catch on irregular objects or surfaces and actually create rotation that would not otherwise have occurred.

The latter is speculation, I think. At least, I am not aware of any research that would rule it in or out.

My personal view is that it's unlikely that helmets have often given rise to injuries that would not otherwise have occurred. My decision not to wear one is essentially based on my calculation that when cycling my risk of any head injury is extremely low, and on the fact that real-world accident statistics do not tend to show that increased use of helmets has a marked impact on the incidence of death or serious injury to cyclists. So, they are probably efficacious for minor injuries but less so in severe crashes. In the former case I'm happy to take the small risk. In the latter, the risk is still small and the helmet is unlikely to make a crucial difference.

My objection to helmet promotion is that it leads people to believe that cycling is a dangerous activity. This discourages people from cycling. Worse, it discourages them from letting their children cycle. That is bad for the public health (the most ardent helmet-promotor would agree, I think, that the health benefits of cycling outweigh the risks) and has al sorts of other negative societal and environmental consequences. And cycling is actually a very low-risk activity. Recent evidence to the Transport Select Committee in the UK parliament, based on official Dept of Transport statistics, indicated that in Britain one cyclist is killed for every 28 million miles cycled. The idea that one needs protective clothing to engage in an activity that safe is ... remarkable. I'll put it no stronger than that.