Music might be the next step in Gwyneth Paltrow's incredibly successful career, but she admits that it hasn't been a seamless transition. 

The actress recently explained that her role in the new movie 'Country Strong', in which she portrays alcoholic singer-songwriter Kelly Canter, left her physically worn down after damaging unusual muscles:

"I had bleeding fingers and cramps and I had shoulder problems, and I thought I had something seriously wrong with me but I had just pulled a muscle in my armpit. It was a disaster."

"I thought, 'My god, I must have all these atrophied muscles in my fingers, 'cause they are not working!'"

Despite the initial pain, Paltrow took to her new calling well as she most recently starred in a few episodes of hit U.S musical comedy 'Glee' and is set to return as substitute teacher Holly Holliday soon. 

Watch her talk about gaining a new fan base with her role in 'Glee' here: