Blaine Hoshizaki, director of the Neuro-trauma Impact Science Laboratory at the University of Ottawa, who also studies head impacts in football, says the problem with STAR is that its tests don't do a good job of simulating some of the situations most responsible for concussions.
"You get hit in the head hard, you get a concussion," Hoshizaki
"It's very hard for a boxer to knock someone out with a straight punch," Hoshizaki
"But a hook works."
And here's the thing: The STAR system doesn't measure rotational acceleration, only linear.
That means that the possibly more dangerous hits, according to Hoshizaki
, aren't even being accounted for.
Here's the other thing: The kind of helmet designed to reduce linear acceleration-bigger, heavier, and with thicker interior padding-may also be the kind of helmet that increases rotational acceleration.
Unfortunately, this is exactly what manufacturers have been making in order to improve their STAR scores.
"If you make a big, fat, soft helmet, you're not just creating low linear acceleration," says Hoshizaki
, who helped design a Xenith helmet that received four stars in Virginia Tech's inaugural rankings.
Sources: Journal of Neurosurgery; Exercise and Sport Sciences Reviews; Stefan Duma; Blaine Hoshizaki.