Ok what about all the trauma of the head skidding against pavement.
Even if the helmet doesn’t prevent all brain injuries it is effective in preventing a lot of the out side of your head from being scrapped off.
Remember he is only seeing the people that come into the ER not the many more that just get up from a crash look at their banged up helmet and walk away.
I was taken down in a race from a rider who hit me from behind shattered my helmet lots of road rash (none on my head) other then that no damage.
I am a firm believer in them.
Road rash is a scalp injury, not a “head injury”.