When former Twins third baseman Corey Koskie suffered a concussion in 2006, few teams — and even doctors — knew how to effectively treat the symptoms. (Star Tribune/The Minnesota Star Tribune)

Nothing exists in itself. If you flatter yourself that you are all over comfortable, and have been so a long time, then you cannot be said to be comfortable any more. -- Herman Melville.

On a tiny dirt diamond 30 minutes west of Minneapolis in Loretto, Corey Koskie is comfortable again. His 12-year-old son is in youth baseball playoffs, and Koskie is throwing batting practice.

It's simple repetition, perfectly routine. He laughs. He ducks out of the way on a sharp base hit. He doesn't touch his head. He's fine.

Only six years ago, the former Twins third baseman unwittingly became something of a test case for concussions in a sport mystified by them when he sustained a non-contact injury with the Brewers. The battle was an uncomfortable one -- for baseball, which had no real concept of the warning signs or risks; for doctors, who were learning as they went; and for Koskie, who was caught between contradicting values from the medical world and his profession.

Since then, more has been learned about concussions. And while the road back from head injuries for current players such as the Twins' Justin Morneau isn't easy, it is helped by the transformation of attitudes surrounding the sport and more advanced knowledge in the medical world -- growth that was, in part, boosted by the 39-year-old Koskie.

Two years after finally finding an answer, Koskie's body and brain have returned to normal, a level of existence he appreciates now. He takes pride in his new job, managing two local Planet Fitness health clubs, a business role he says he taught himself. He spends the rest of his time with his wife, Shannon, and their boys Bradley (12), Joshua (10), Caleb (7) and Samuel (2) at their Plymouth home, or getting his baseball fix through coaching his oldest three.

"I'm at a better place because I have a completely different perception now," Koskie said. "I'm a different person, because I know what it's like to not have this."

In 1993, Koskie was living a comfortable life as a sophomore at the University of Manitoba in Canada, when he abruptly left his country, his scholarship and the two sports he knew the best -- hockey and volleyball. He went to Boone, Iowa, and made the cut on the baseball team at Des Moines Area Community College, where the coach had seen Koskie play Canadian town ball.

A year later, he was enrolled in the National Baseball Institute in British Columbia, where he was spotted by the Twins and drafted in 1994. By 1998, Koskie made his big-league debut. He had several solid seasons with the Twins before leaving in 2004 as a free agent to Toronto, where he had always wanted to play.

Before the 2006 season, Koskie was traded to Milwaukee, where on July 5 in a game against Cincinnati, he fell backward while trying to catch a ball. He was never the same ballplayer again.

"I felt fine immediately afterward," said Koskie, who now estimates he has had eight to 10 concussions in his life, most of them less serious. "But when I went to the dugout, I just thought, 'Huh. I feel kind of funky.'"

Koskie stayed in another inning, so dazed that he had to go through step-by-step instructions in his head to get through an at-bat before striking out swinging. He went inside the clubhouse to the team doctor, who diagnosed him with a concussion.

"But he said it would be fine in a couple days," Koskie said. "They said it was no big deal because I didn't hit my head."

A concussion occurs when a sudden acceleration or deceleration of the head causes the brain to collide with the skull, causing the brain to ricochet or rotate inside the skull. Inside the brain an injury has occurred, but outside, there are few tangible indicators of major distress. No bandage is necessary. MRIs and CT scans show up negative. Physical tests prove worthless.

"It was, 'What do we do with this person?'" said Rick Aberman, Director of Peak Performance for the Twins, who worked with Koskie when he was with the Brewers. "Many athletes say, 'I wish I had a cast on my arm to let people know I'm hurt.' Because you look fine."

The Brewers medical staff was baffled, Koskie said, and began conferring with the Green Bay Packers staff for advice. After a week of confusion and extreme fatigue, Koskie was sent to a neurologist, who instructed him to rest a full week after the symptoms stopped before doing anything physical. But on the day after Koskie reported feeling better, he said, the team asked him to join them in Arizona for a road trip.

"They told me they talked to the Packers doctor," Koskie said, "and he said, 'If we followed those guidelines we wouldn't field a team on Sundays.'"

Koskie was uncomfortable as he rejoined the team and went through a full 45-minute workout, feeling dizzy the whole time. When he woke up the next day, he could barely move. His symptoms had dramatically worsened overnight. He and his family flew back to Milwaukee, just in time for Koskie to sleep through the All-Star break and family vacation.

"We didn't know what to do," Shannon Koskie said. "All the doctors were pretty much like, 'You'll be fine. You'll get through it.' There was no information given to us."

Koskie kept trying to be the dad he once was, but inevitably the effort had the opposite effect. He slept a lot and had a hard time doing much of anything.

"I think it really affected Bradley," Shannon said. "He would say, 'Daddy used to play with me more.'"

Koskie was treated for anxiety problems, social disorders and emotional imbalances. Some of it was team-prescribed, but none of it was paid for by the club, Koskie said. He accumulated $120,000 in medical bills before the MLB players association negotiated a partial return for him around 2007.

Until fairly recently, concussions were thought to be caused only by a sudden blow to the head. Even doctors that understood Koskie's concussion were still learning how to treat it.

"We used to think that doing nothing and resting was best, but I don't believe that now," said Dr. Mickey Collins, a specialist at the University of Pittsburgh, whom Koskie started seeing in 2007 and said was the first person to understand his problem. "If I saw [a patient] now, my whole rehab approach would be much different than if I saw him six, seven years ago."

In 2009, Koskie saw physical therapist Dr. John Groves, who saw the clip of Koskie getting hurt and had an idea. Groves started treating Koskie for both whiplash in his neck and concussion symptoms in his brain, finding that when he used neck manipulations in tandem with exercises focusing on eye movement, the latter improved drastically.

"He was really the first one I treated this way," Groves said. "I always kind of joke that the guy that taught me the most about concussions was Corey Koskie."

Within three weeks, Koskie was able to work out without symptoms. A few months later, he was ready to try to play again. But after sitting on Team Canada's bench in the 2009 World Baseball Classic, going through a spring training with the Chicago Cubs and nervously doing self-checks after every diving catch, Koskie hung up his cleats. He settled into his new career and a regained role as an active dad. He talks to Morneau, a good friend, about his experiences.

"He went through a bad time," said Morneau, who suffered a concussion midway through the 2010 season and has struggled to stay healthy and perform to pre-concussion standards since then. "I think there is a lot more emphasis put on erring on the side of caution now. Who knows what would have happened [to me back then]?"

A laid-back Koskie sits on a bench, watching the coach across the little league diamond with a tickled expression.

"You're going to be able to watch some coaches scream at little kids here," he said, shaking his head. "I don't think the parents like me very much either because I'll tell them 'I'm sorry. We didn't offer you the ability to ump today.'"

Koskie's joking, but he takes coaching seriously. Since returning from his concussion, he's also taken up a new hobby: reading. After a few years of scarcely being able to scan a newspaper, he has read between 15 and 20 books in the past six months. The subjects mostly have to do with leadership and management -- skills that help him with coaching kids, with his new job and have him thinking about someday getting involved with leadership development in baseball or helping athletes transition from their sports to "the real world."

"I've been self-taught my whole life," Koskie said. "I just have this quest for ongoing knowledge."

And he has time to make up.

But he isn't bitter about being the test case for concussions in baseball -- or how it altered his career.

"Every once in a while, I miss the actual game," he said. "I miss playing it, getting the short hop and the feel of the ball in your glove. That kind of stuff. ... But would I trade those three years I spent at home for three more years playing in the big leagues? You can't say that. There's stuff that happened in that time."

Perspective happens. There was a time when Koskie said he all he could do was sit in Milwaukee and "watch the boats go by." Koskie appreciates sitting now, as he watches his son play, because it's a choice.