Natalie Portman Was Injured on Her New Film -- and Swapped Her Trailer for a Doctor (VIDEO)

Actress Natalie Portman started dancing lessons at age four. Still, she wasn't quite ready for her performance in the upcoming film 'Black Swan.' In the film, Natalie and fellow actress Mila Kunis play rival ballet dancers. But even after undergoing ballet training for six months -- for five hours every day -- Portman still got injured.

On 'Late Show' (weeknights, 11:35PM ET on CBS) Natalie described her injury to David Letterman -- and explained what she had to do to get medical treatment. Portman was hurt while being lifted in the air by one of her dancing partners. The actress "dislocated a rib -- it sort of went under another one." "Whoa," Letterman said.

Natalie then asked the producer if he could get a medic to give her "an ice-pack or an Advil or something." But as it turned out, the film was so low-budget that they didn't actually have a medic. Whoops.

Portman was shocked that there was no doctor on the set: "I don't even think that's legal. ... Before you take away a medic, take away my trailer." She got her medical attention (eventually), but there was a price for it. The next day, she "didn't have a trailer" anymore. Yep, her on-set housing was gone. Whoops again. Okay, so Natalie had to swap her trailer in exchange for a medic. But hey, at least she suffered for her art -- which in this case included dancing and acting.