Severity Index (I assume this is based on the head injury criterion?)
Actually, in an email they said the head of NOCSAE did the test, so presumably the NOCSAE Severity Index was used. An NOCSAE article says, "There is no measurable difference in safety of helmets with scores below the 1200 SI threshold." So in other words, in the test the hats did not protect against any significant damage, because no significant damage was done even without the hat. Despite this, the webpage said said that, "The Crasche hat reduces the severity of blunt force impact by 94%." I count this deceptive marketing as a strike against the product.
That said, given the low cost of purchasing and wearing the hat, it seems worthwhile for a transhumanist to purchase, simply due the vast gains to be had from a slight reduction in risk of death.
Interesting - thanks for checking this. If the Severity Index is claiming no significant damage below 1200, I think it may be incorrect or may have a different criterion for severe damage. Some helmet standards seem to be fairly insensitive, only accounting for moderate or severe brain injury whereas MTBI can have long lasting effects. Yes, I discount Severity claims as the metric does not appear to give reasonable results. 188g is a crapload of linear acceleration, but metric puts it under threshold...I dont buy it, so am left to judge on peak linear accel instead (shame that rotational accel was not measured...)
A 2006 study showed that “280,000 people in the U.S. receive a motor vehicle induced traumatic brain injury every year” so you would think that wearing a helmet while driving would be commonplace. Race car drivers wear helmets. But since almost no one wears a helmet while driving a regular car, you probably fear that if you wore one you would look silly, attract the notice of the police for driving while weird, or the attention of another driver who took your safety attire as a challenge. (Car drivers are more likely to hit bicyclists who wear helmets.)
The $30+shipping Crasche hat is designed for people who should wear a helmet but don’t. It looks like a ski cap, but contains concealed lightweight protective material. People who have signed up for cryonics, such as myself, would get an especially high expected benefit from using a driving helmet because we very much want our brains to “survive” even a “fatal” crash. I have been using a Crasche hat for about a week.