[John Greist]

The FIA Institute information m bell provided 4 days ago (thread #139)(http//www.fiainstitute.com/document...ans%20%22) is instructive about correct installation and positioning of the HANS device. The shoulder harness anchor points of the RT-2000 were adjusted a few years ago to be the best possible with that chassis' frame and the new car should offer anchor points even better for shoulder harness positioning vis a vis HANS use. Correct harness positioning for different body heights is critical as descriptions of harness slipping off the HANS yoke identifies a correctable design flaw. The newer HANS with lip on the outside of the yoke may reduce slippage, but Revere and I have never had a shoulder harness slip off and our HANS are 8 years old, smooth on top and without a lip. Fit is important.

Dr. Mike analogized from shaken baby syndrome: Shaken baby syndrome is a type of inflicted traumatic brain injury that happens when a baby is violently shaken. A baby has weak neck muscles and a large, heavy head. Shaking makes the fragile brain bounce back and forth inside the skull and causes bruising, swelling, and bleeding, which can lead to permanent, severe brain damage or death. The characteristic injuries of shaken baby syndrome are subdural hemorrhages (bleeding in the brain), retinal hemorrhages (bleeding in the retina), damage to the spinal cord and neck, and fractures of the ribs and bones. These injuries may not be immediately noticeable. Symptoms of shaken baby syndrome include extreme irritability, lethargy, poor feeding, breathing problems, convulsions, vomiting, and pale or bluish skin. Shaken baby injuries usually occur in children younger than 2 years old, but may be seen in children up to the age of 5. (from National Institute of Neurological Disorders and Stroke).

How well this brain injury in babies relates to what occurs in adolescent and adults in racing crashes with or without HANS devices is unknown. After a sudden high G stop, concussion can occur when brain hits the inside of the skull (coup = blow) followed by rebound (counter-coup) against the other side of the skull, with varying degrees of recovery - more often than not complete.

If it comes to it, I prefer James Bond's "shaken but not stirred" martini formula. Basilar skull and cervical fractures have and can be lethal, and are the main injuries HANS is intended to prevent. I do not have and cannot find studies of HANS benefits and would certainly like to read them if others know specific citations. I expect there may be engineering design studies, but as we can all understand, randomized controlled trials with humans crashing are hard to conduct. We've all been hypothesizing (speculating) about HANS benefits and risks based on beliefs rather than knowledge. Similar study design problems occur with regard to risks and benefits of parachutes, and a randomized controlled trial design addressing this issue was proposed in the British Medical Journal (http://www.teamjuicyracing.com/pdf/Parachute.pdf).

Back to HANS in Skippy cars: Testers uniformly (Bobo may be an exception) do not wear them in RT-2000s, but do when racing in series that require them. As role models, if testers wore HANS that would be the most effective way to spread their use. The growing use of HANS has happened without this role modeling. Testers crash at a far lower frequency than we do and can usually ameliorate the end result to some extent better than the rest of us.

I think we're at a point where each must decide what to do each time s/he gets in a race car. I wear my HANS all the time - except when I forgot it once at a school car lapping day at RA and drove, feeling naked at first, then lulled into forgetfullness by the pleasure of the drive. Even with a HANS, bad things can happen to one's head - witness Christina DeMatta's severe injury on the straight between turns 5 and 6 at RA.

Acknowledging uncertainty, I prefer the HANS until evidence convinces me the odds favor not wearing it.