ONALASKA, Wis. -- Concussions have been a hot topic and a cause for concern in the sport of hockey recently. Head injuries have had serious effects on many NHL players including the face of the league, Sidney Crosby.

It's a situation that is all too familiar to Coulee Region Chill forward Tommy Miller.

Miller was playing with the Philadelphia Revolution of the Eastern Junior Hockey League two years ago when he was crushed by a blind side hit.

"My head was turned all the way around so I didn't see any guys coming," he recalls. "As soon as the puck came to me guy right there just head-on collision. Just full speed."

Miller doesn't remember much after the hit.

"I remember I was on my knees. Couldn't get up. Tried to stand up and just bambi-legged it. Just could not get up and just being really nauseous."

Miller had to sit out an entire year dealing with post-concussive symptoms. He had to pass extensive mental tests, like saying the alphabet backwards and counting. Players also have to go through physical testing, like non-contact gameplay and sprints, before they can step back on the ice.

"It's a lot of work just to come back from any injury," says the forward from Miami, Florida. "But especially a concussion because it's always there in the back of your head. Am I going to get hit again."

Head injuries have been thrust into the national spotlight after three NHL enforcers died over the summer.

The issue got even bigger when the New York Times reported that one of the players, former Minnesota Wild enforcer Derek Boogaard, suffered from Chronic Traumatic Encephalopathy. Boogaard died in May of an accidental drug and alcohol overdose.

CTE is a brain ailment that is related to Alzheimer's Disease that is caused by repetitive brain trauma.

The research linking CTE and athletes is new and ever-growing. It is unknown if CTE was a contributing factor in the death of Boogaard.

The issue of head hits is something seen by players at all levels of the game.

"We know that if you've had prior concussions your chance of having a second or third concussion is much higher," says Gundersen Lutheran Physical Medicine and Rehabilitation Physican Jeffrey Derr. "The amount of impact it takes can be lower.

There have been rule changes sport wide to enforce stricter penalties for hits to the head. With bigger, faster, stronger athletes in the game today, using mouthguards and other safety equipment is more important than ever.

"When you're playing peewee, bantam, and into high and juniors you have a responsibility to take care of yourself," says Chill assistant coach Jake Fleming. "For me as a player it's putting your gear on the right way and wearing your mouthguard."

Chill head coach Garrett Strot says it also comes down to respecting your opponent.

"When you're going against another guy you just have to have respect and keep your hands and elbows down," he says. "That's what I tell our players all the time. When you're going in to hit, keep your hands and elbows down and you'll be fine.

Even though Miller is two years removed from a concussion that could have claimed his hockey career, he says he will continue to play for his goal of a Division 1 scholarship, but he will proceed with caution when it comes to head injuries.

"Definitely down the road you start to get a little more cautious with it," he says. "But you want to take care of yourself because there is life after hockey."