[Ram Jet]

Originally Posted by danno25nh

I'm going to self proclaim as highly knowledgeable in the subject.

My profession and education are Biomedical Engineering.
I also played Hockey for 50 years and had my final boxing match at age 49 and 364 days. I've lost count of the concussions, though I do suffer the consequences. In my desire to continue playing and fighting I spent considerable time researching helmets and helmet technology.

Concussion occurs when the brain impacts against the skull such as when head hits pavement, through rotational movement such as severe twisting of the head, and also on rebound.
When we have a hard impact, the brain slams into the skull on the side of the impact and then rebounds and hits directly opposite. This is known as a contracoup injury.

A helmet might mitigate the deceleration injury (concussion) through good design, but short of being a 1 meter diameter nerf ball around our head it can't prevent it.

What a helmet can do is spread out the impact and absorb the impact preventing damage to our skull and face bones.

Some deceleration mitigation is evident in today's helmets and in some cases some rotational protection is being designed.
Hockey helmets in particular are incorporating rotational protection.

If that sounds as if I'm saying any helmet works, rest assured I'm not. Good does not mean expensive but always and every time wear a good helmet.

I personally from an engineering point see little value in DOT and Snell.

ECE looks much better for real world impact. I looked at the SHARP ratings and made the personal decision to never purchase less than 4 star SHARP and ECE rated helmets.
I ended up with a $100 LS2 Arrow.

Finally, a common sense/scientific explanation effects of of head impact. $800.00+ is for a motorcycle helmet is Gods way of sayin' you're makin' too much money.

Bill