Kidney stones, the result of a build-up of minerals in your urinary tract, are painful to pass and expensive to get rid of, with procedures costing between $5,000 and $10,000. A cheaper, and more thrilling, alternative to a trip to the hospital may be a trip to a nearby amusement park.

A new study published in the Journal of the American Osteopathic Association found that kidney stones moved through a 3-D-printed kidney when they were taken on Disney World's Big Thunder Mountain Railroad ride. This ride in particular was chosen because Dr. David Wartinger, who led the study, had received reports of his patients passing stones after riding the coaster.

The model kidneys were suspended in urine and housed in backpacks worn by researchers who rode the roller coaster. A small preliminary study found that those who sat in in the last car — where the riders were more likely to be whipped around a bit — had a 64 percent "passing" rate compared to the 16 percent rate of those sitting at the front. A larger study corroborated the seating results, at least so far as Big Thunder Mountain Railroad was concerned. Researchers also tried Space Mountain and Aerosmith's Rock 'n' Roller Coaster for comparison.

Wartinger explained to MSU Today that roller coasters with upside-down sections and ones that go too fast aren't going to help pass the stones because G-forces will keeps the stone pinned down in the kidney instead of allowing it to move through the kidney.

"The ideal coaster is rough and quick with some twists and turns, but no upside down or inverted movements," he said.