Big hits leading to brain injury is nothing new in sports like hockey and football, but now researchers are warning about the rise of concussions in soccer.

Calgary South West United Soccer Club player Alix Kuhn missed four months last season due to a serious blow to the head.

"I've already had like two or three concussions and I don't want it happening again because that might be the end of soccer."

Some researchers now say female athletes in soccer top the list for sport-related concussions. There are still many unknowns as to why, however, some doctors are taking a closer look at the number of times players head the soccer ball.

"The one that we don't really understand is the repeated heading of the ball," said Dr. Remo Panaccione, who works with the Calgary club. "That actually is associated with the exact pathophysiology that causes a concussion."

Trainer Noel Smith said a lot has changed since he played. Smith said he's probably suffered four or five concussions over his career, but never treated them properly.

"I remember there was one main concussion that I had. My mom was told it was a concussion, but I didn't take any of the precautions they take now," said Smith.

In Calgary, athletic therapists at the Alpine Sport Therapy Centre are getting serious about understanding concussions in soccer. Director Kristin Streed said the biggest challenge is changing the stigma around concussions in sport.

"We used to say we got our bell rung, shake it off, and go back in because there just wasn't research to tell us anything else," said Streed. "Now we know a lot better."

"We want to learn more and more about sub-concussive hits… how many hits can a person sustain without any repercussions from that?"

The Alpine Sport Therapy Centre has already dealt with three soccer concussions so far this season, all of them during practice.