I've seen that claim based on anecdotal evidence and wikipedia entries--I personally choose not to risk my safety to that kind of evidence. I've never seen the claim that bicycle helmets increase injuries in peer-reviewed journals. While I don't make a habit of scouring the medical journals, I've also never met someone from any level of the medical profession advocate *not* using a helmet to increase safety.


I suspect he was being facetious, but just in case, smaller surface areas exert more force than larger surface areas. Hitting someone with a hammer is going to exert significantly more force than hitting a curb...not that I advocate doing either one of them


*EDIT*
There is one thing I think people should consider since it's been brought up a few times. If bicycling accident rates are anything like automobile accidents, then the vast majority of low speed, inconsequential accidents occur in familiar places. This phenomenon is most often attributed to people being less alert when they are traveling short distances and most often when they don't expect danger.

Couple that factoid with the notion that most people seem to be concluding that bicycle helmets are most effective at low speed "fender benders" rather than high speed collisions and one should conclude that helmets would provide maximum effect close to home, on short rides, at low speeds rather than long, unfamiliar, high speed rides.