Scientists can't peer into the brains of hockey players the instant they get a concussion, so University of Ottawa researcher Blaine Hoshizaki does the next best thing.
He reconstructs hits to the head in the National Hockey League using metal head forms and equipment that can land a blow in precisely the same way, for example, that Dave Steckel's shoulder connected with Sidney Crosby's head. A sophisticated computer model then shows the impact on brain tissue, the stress and strain as it rotates slightly inside the skull or when different parts of the brain move against each other.
It is this kind of movement inside the skull that causes concussions, also known as mild traumatic brain injuries, and Hoshizaki wants to learn more in order to build a better helmet.
Hockey helmets do a good job of protecting players from catastrophic brain injuries such as skull fractures, but Hoshizaki hopes his research will eventually lead to designs that are more effective at preventing concussions.
On Wednesday, the doctor summarized his findings for the Reebok-CCM Hockey Safety Summit in Ottawa, which brought together representatives from the NHL, Hockey Canada, USA Hockey and other organizations. He described how helmets are now tested only for linear acceleration, which occurs, for example, when a head hits the ice. But he says they should also be tested for how they perform when a hit comes from the side.
Charles Tator, a University Health Network neurosurgeon and leading authority on concussions, says the work is an important step toward learning if there is a way to make helmets that offer significantly more protection against concussions.
"I think it will help us figure out what to do about helmets."
Reebok-CCM has agreed to help to finance Hoshizaki's work, along with the federal government, although those details are still being worked out.
Hoshizaki did simulations of both of the hits to the head suffered by Crosby, star centre for Pittsburgh Penguins, during the first week in January.
The first was on Jan. 1, from Steckel, a winger for the Washington Capitals, the second on Jan. 5 from Tampa Bay Lightning defenceman Victor Hedman.
The analysis showed that the first hit was more serious, says Hoshizaki, and had higher risk of causing a concussion. Crosby hasn't played since the game on Jan 5.
Concussions can be tricky to diagnose. A player can skate away from what appears to be an extraordinarily hard impact to the head, says Hoshizaki, while others are out for months after an impact that appears to be more subtle.
He suspects some parts of the brain may be more vulnerable, and that there may be, in fact, different kinds of concussions depending on what part of the brain is most affected.
"Different concussions will have different characteristics. We are trying to recreate these conditions," says Hoshizaki, who also works on football helmets.
Researchers aren't sure how brain cells are damaged by the kind of movement that causes concussions.
In recent years, scientists have gained crucial new insights into how the injuries affect athletes' brains, both in the immediate aftermath of a hit - and possibly long after they've retired from the sport. They are investigating the long-term impact of repeated concussions amid growing evidence that they may be linked to an Alzheimer's-like condition associated with personality changes and dementia.