McMaster doctor treating boxers ringside in Rio

Most doctors aren't sitting and watching their prospective patients get punched in the face — but Dr. Kien Trinh isn't your average doctor.

Trinh, a clinical professor of Family Medicine at McMaster's Michael G. DeGroote School of Medicine, is at the Rio Olympics as the Field of Play Physician in boxing.

"Most physicians do try to do preventative work," Trinh told CBC News from Brazil — but his work near the ring can end up being a little more reactionary.

He has seen cuts, bloody noses and concussions. One particularly gruesome separated shoulder made some in a crowd wretch at an event several years ago, he remembers.

Every time I see a boxer get knocked down, it does make my heart beat faster.- Dr. Kien Trinh

His stitches aren't the "five minute" jobs you get at your local emergency room, he says. He's stitching people up for 45 minutes to an hour to seal up a cut "properly."

"When they get pounded in the same place, it can pop back open," he said.

This is Trinh's third Olympics, having worked during the 2004 games in Athens and the Beijing games in 2008.

He also served as the team physician for Canada at the 2003 and 2007 Pan American Games in the Dominican Republic and Brazil, and most recently as the lead physician for the boxing complex during the 2015 Pan Am Games in Toronto.

He got his start in a bout back in the mid 90s, when the ringside doctor was ill. Trinh had previously treated the Canadian team's ringside coach, who asked him, "Do you know anything about boxing?"

He said he didn't.

"Weren't you a Taekwondo black belt?" the coach responded.

Yes, as a kid, he said.

"Close enough," the coach responded.

He journey spiraled from there. He's now an International Boxing Association certified ringside physician, and has covered many other professional combat sports, including the Ultimate Fighting Championships, judo, and karate.

"Despite the intensity of the sport, the number of injuries we see are quite few," Trinh said.

But the rush of the sport is inescapable, even for a seasoned medical pro.

"Every time I see a boxer get knocked down, it does make my heart beat faster," Trinh said.