Well, I wouldn't have been interested in this except for something that happened to me about 20 yrs. ago. I was riding my bike in Central Park when someone clipped me with their bike from behind & I felt myself falling forward (no helmet) over my handlebars, everything slowed down & I felt hands on my shoulders pulling me back onto the seat. I fell off the side of the bike & rolled about 20 ft. sustaining only a few bruises. A man came running, introducing himself as a dr. from nearby Mt. Sinai hospital. He said he saw me lurch over the handlebars & ran towards me expecting to see a head injury. He asked me how I managed not to fall forward it but I don't know how that happened.