Many of people ask me about bicycle helmets. Do they work? Should they wear one? They heard that study XYZ said they didn’t do anything so they don’t wear one. In the past few months I’ve been involved in some relatively heated debates with people, typically cycling advocates, who say that helmets do not work. This post is a reflection on this notion that helmets don’t “work” and an attempt at an interpretation of what I think cycling advocates are trying to say.
First off, here is a quote from a recent Rune Elvik paper on bicycle helmet us:
Do bicycle helmets reduce the risk of injury to the head, face or neck? With respect to head injury, the answer is clearly yes, and the re-analysis of the meta-analysis reported by Attewell et al. (2001) in this paper has not changed this answer. As far as facial injury is concerned, evidence suggests that the protective effect is smaller, but on balance there does seem to be a slight protective effect.
Elvik does very good work and the study mentioned above does considerable re-analysis of existing meta-analyses and review studies. There are still lots of methodological issues at play, as Elvik mentions but for now the evidence seems to suggest that helmets do protect against head and facial injuries.
Now here is a summary TED talk by famous cycling advocate Mikael Colville-Andersen about why we should not wear helmets. I think this talk is a good summary of the arguments I hear about helmets and cycling from many cycling advocates. It is also quite funny and well done.
I’ll skip over the obvious appeals to scientific authority that are very evident in his talk, despite his attempt to simultaneously critique them.
The logical flow of his talk goes something like this: Helmets don’t work, people are scared, cars are extremely dangerous and should be legislated in some way to make them safer, bicycling prevalence is going down because of helmet advocacy, helmets don’t work.
This argument confuses different ideas about the role of the helmet in society and individual versus population risk. At the individual level, as a cyclists, knowing the evidence from the study above and other studies, I wear a helmet. It will reduce my risk of injury if I crash or am involved in a collision. At the population level Colville-Andersen is correct is stating that requiring motorists to wear helmets will likely have a much bigger impact than mandating bicycle helmets. This is in part because, particularly in North American, the prevalence of cycling is very low, while the prevalence of driving is very high.
The bigger debate is around safely increasing the prevalence of cycling rather than placing the majority of the blame on cyclists and cycling helmets. Particularly in North America, as a individual cyclist with few separated cycling lanes, wearing a helmet does nothing to reduce my likelihood of being involved in a collision. I’m still going to get hit, I’m just not going to get hurt quite as badly when I do. Improving cycling infrastructure would likely go much further than mandating helmet use to increase the prevalence and simultaneously increase the safety of cycling (though the scientific evidence is not completely in agreement on this statement).
I think the cycling community needs to be clear on the role of helmets as individual safety measures versus as a population level strategy to reduce the likelihood of injury. Focusing on the former misses the bigger picture and distorts the view of many people who are not directly involved in the cycling community (that is to say… most people in North America).
Many will not agree with me. Debate and discussion are encouraged.