Cancer is no laughing matter, but even Gwyneth Paltrow had to giggle at herself when soreness over learning to play the guitar for her role in 'Country Strong' took her mind to a scary place.

"I had bleeding fingers, cramps, shoulder problems," she told The Boot during a press roundtable for the film. "I was like, 'I think I have cancer!' But I pulled a muscle in my armpit. It was a disaster. I went to the doctor and they were like, ' You pulled a muscle.' Oh God, what a nerd!"

Learning to play guitar was an exercise in frustration for Gwyneth. "My fingers wouldn't respond to the signals my brain was [sending]. It took so long to get my fingers to do what my brain wanted them to do and I thought, 'My God, I must have all these atrophied muscles in my fingers.' Other people can play guitar, but I can't get my hands to do [it]."

While it would seem that playing a broken-down alcoholic would be incredibly difficult, Gwyneth found the process as liberating as she found it challenging. "That was very hard, but also very cathartic and I loved playing somebody who was kind of coming off her hinges," she admits. "My life is so ordered, I'm so organized and I loved playing someone who didn't worry about consequences, in a terribly way, by the way. But there was something very liberating about being somebody who was just that reckless because I'm the opposite of an actor, it was just a dream to play her...There was so much freedom in playing Kelly Canter and I was sad to let go of that."

'Country Strong' hits theaters nationwide on January 7.

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