Margot Robbie struggled with herniated disc after ice skating movie fall

Margot Robbie suffered on skates as she portrayed ice skating queen Tonya Harding, herniating a disc after a nasty fall on the ice.

The Australian actress grew up obsessed with ice hockey, and put on her skates for half a season when she first arrived in the U.S. - until her acting career took off and her hobby became too much of an injury risk.

But flying around in heavy hockey gear didn't really prepare Margot for her role as Tonya in I, Tonya.

"I joined an ice hockey league and played for half a season until I started working on (TV show) Pan Am," the Suicide Squad star explains. "That was my ice skating knowledge and I really oversold that part of it when I did my initial pitch to (screenwriter) Steven Rodgers.

"I said, 'Oh, I'm a great ice skater; I played ice hockey'. In hindsight, I was really just running on the ice with so much padding on, there were little to no repercussions. Once I had no padding and a toe pick on the end of the ice skates for figure skates, it was a world of pain.

"I did herniate a disc and had I not been a producer I would've checked into rehab for my neck, but because I was a producer I was like, 'We can't afford that so shoot me up with some steroids and let's keep going!'"

Margot underwent MRIs at the end of each week to make sure it was safe to keep going.

But, as hardy as she was as Harding, there was one famous ice skating trick she wouldn't even try.

"No one can do the triple axel," she adds. "Six women can do it since Tonya did it 25 years ago. And so we had to CGI for the triple axel with a skating double in the end, because no one could do it."