Going back into the 70's and I was Kart racing. Helmets were compulsory but there were 2 deaths within a short space of time and both head injuries. The post mortems on both came to the conclusion that both drivers had an underlying problem in that the Brain was not protected sufficiently in these two people- by the thinness of their skull structure. They could have been killed by walking into a door.
I am a helmet believer and I have had a couple of accidents where headaches have occurred afterwards- Whether the helmet saved Further damage or concussion- I do not know but I have had a couple of incidents where the face and Skull have been saved from wearing away on the tarmac. The helmet took the brunt of the Scraping and it is surprising how little it takes to wear away styrofoam at 10 mph on black Ice.
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How long was I in the army? Five foot seven.
Spike Milligan