Originally Posted by
B. Carfree
I've been wearing a helmet since the '70s. However, there is no denying that in some crashes, like the one described in the OP, a helmet can make things worse. I would not be surprised if the helmet didn't contribute to the broken vertebra. I can't prove it any more than the OP or you can prove that the helmet prevented the injuries from being worse than they are. The data regarding bike helmets is still rather unconvincing for any crash other than a stationary fall.
Now, I believe there is some data showing that helmet use in motor vehicles, whose occupants have many more head/brain injuries than cyclists, would help reduce the frequency and severity of those injuries. Of course you are wearing a proper helmet when you are in a car, aren't you?
I think recognition of the incidence of head trauma trend in vehicle accidents resulted in the introduction of frontal air bags, and now the wider adoption of side-impact air bags. So this long-held opinion by cycling advocates is losing its relevancy to a certain extent.
Admittedly, a helmet might be a cheaper alternative.