Roller coasters can help cure kidney stones, says an academic free-rider, and sufferers will get the best results if they sit in the last car.
David Wartinger, a Michigan State University professor, conducted his kidney-jarring roller coaster study at Disney World, according to online alumni magazine MSU Today.
He was determining whether stories he was hearing from patients that roller coaster riding helped them with their kidney stones were true.
Wartinger used a 3D model of a hollow kidney containing three kidney stones stuffed in a backpack as he rode on Big Thunder Mountain at the theme park 20 times.
"Basically, I had patients telling me that after riding a particular roller coaster at Walt Disney World, they were able to pass their kidney stone," Wartinger told MSU Today. "I even had one patient say he passed three different stones after riding multiple times."
"In the pilot study, sitting in the last car of the roller coaster showed about a 64 percent passage rate, while sitting in the first few cars only had a 16 percent success rate," he said.
According to his study published in the Journal of American Osteopathic Association, the roller coaster rides were examined "using variables of renal calculi volume, calyceal location, model position on the roller coaster, and renal calculi passage."
"The functional pyelocalyceal renal model serves as a functional patient surrogate to evaluate activities that facilitate calyceal renal calculi passage," said the study. "The rear seating position on the roller coaster led to the most renal calculi passages."
Wartinger told the Lansing State Journal that the roller coaster's rough ride and quick turns likely helped the stones move along their merry way. The professor added, though, that passengers should avoid roller coaster with inverted loops and upside down movements.
In an expanded study with Michigan State resident Mark Mitchell, Wartinger
said there was a nearly 70 percent success rate using 174 kidney stones, with a 100 percent passage rate if the stones were located in the upper chamber of the kidney, noted MSU Today.
He added that the potential cost savings for everyone from patients to employers and insurance companies, regardless of the current price of Disney World tickets, are substantial.
"We want to offer people something cheaper than a $5,000 Lithotripsy," Wartinger told the State Journal, referring to the procedure which breaks up large stones using ultrasound shock waves. "I can tell you, if insurance companies want to save money, they'd cover visits to amusement parks."