In our quest to learn more about the effectiveness of helmets, we've come across the terms "Hangmans Noose Analogy," and "Basal Skull Fracture." The cause of this type of injury is the retention system of the helmet exerting extreme pressure on the head/neck complex and acting much like a hangman's noose by breaking the neck, or causing a fracture at the base of the skull.
A May 20, 1996 AP news release reported on the tragic death of Indy 500 driver Scott Brayton, whose autopsy showed that the Indianapolis 500 pole-winner died of a basal skull fracture. (Remember, these drivers wear the supposedly superior full-face helmets.)
Speedway Medical Director Dr. Henry Bock said Brayton was killed during practice, but did not elaborate on the injury.
Brayton, 37, who had started 14 previous 500's and captured the pole position in 1995 and 1996 died 30 minutes after the crash. Clearly the full-face helmet and restraint system did not prevent this fatality, in fact given the information we have about helmet design and chin strap problems, it's very likely that the cause of death was the helmet itself.
K. Peter Krantz with the Department of Forensic Medicine at the University of Lund, Sweden, noted that ring fractures of the base of the skull were present in 21 out of 132 cases of motorcyclists whom he studied. Seventeen of these riders were wearing a helmet. Three riders suffering ring fractures of the base of the skull, and two riders who suffered disruption of the junction of the head and neck, did not show any sign of head impact, except for minor abrasions of the chin strap. These injuries are due to the result of a centripetal movement, owing to decreased velocity of the body in relation to the head.
The Brayton death makes the fifth such race-related fatality we attribute to helmets. The apparent lack of details about the autopsy results seems to indicate that nobody is willing to place the cause of Scott's death where it belongs - on the helmet. Of course, this would be an obvious contradiction of everything NHTSA and others are saying. Their contention is that helmets are safety devices, and no evidence exists that they cause cervical spine or basal skull injury.
Who is fooling whom?