Roller coaster relief: Theme park rides may aid passage of kidney stones, study says
It may sound wacky, but Dr. David Wartinger, a professor emeritus at Michigan State University’s College of Osteopathic Medicine, became more than a little curious after hearing numerous patients say they had passed kidney stones after riding the Big Thunder Mountain Railroad at Walt Disney World in Orlando, Florida.
In one particular case, a patient told Wartinger that he passed one kidney stone after each of three consecutive rides on the roller coaster.
The testimonies, combined with media reports about people who passed kidney stones while bungee jumping and riding roller coasters, were enough for Wartinger and his colleague Dr. Marc Mitchell, of the Doctor's Clinic in Poulsbo, Washington, to jump into action.
In the name of research, the two left Michigan in search of sunnier skies in Orlando, Florida.
"It was a terrible burden," Wartinger jokingly said, as quoted by NBC News.
Unfortunately – for science, not for themselves – the two researchers didn't have kidney stones of their own to test the theory with, so they made a 3D kidney replica out of clear silicone gel. They filled it with real urine and implanted three real kidney stones of various sizes into the upper, middle, and lower passageways of the model.
The fake organ was modeled after the kidney of the patient who said he passed three stones after three rides on the Disney coaster. The stones were also the same ones he had passed. The origins of the urine remain unclear, perhaps for the better.
The researchers then rode the roller coaster while holding their kidney model between them in a backpack, positioned at kidney height.
For the sake of science, they rode the Disney roller coaster 20 times. They sat in different areas of the ride every time, noting the different effects that each section had on the kidney stones. It turns out the back of the roller coaster was the most beneficial.
“Front seating on the roller coaster resulted in a passage rate of four of 24,” the researchers wrote in the Journal of the American Osteopathic Association.
"Rear seating on the roller coaster resulted in a passage rate of 23 of 36,” they continued.
The tactic isn't incredibly precise or technical. In fact, it's really just about shaking the kidney stone out of the tubes that are inside the kidney and into the ureter – the tube that takes urine to the bladder and out of the body.
But the researchers believe they're onto something – and it's not a magic effect of the Big Thunder Mountain, so those who can't afford a trip to Disney World needn't worry.
"It's not like there anything unique about this one coaster," Wartinger told NBC News, suggesting that a similar roller coaster would likely have the same effect.
“The Big Thunder Mountain roller coaster is not a terribly dynamic ride," he said. "It's not very fast. It is not very tall. It makes sharp left and right turns that have some vibration."
After 200 more test rides on the Disney coaster (for science), Wartinger and Mitchell say their findings are consistent and “support the anecdotal evidence that a ride on a moderate-intensity roller coaster could benefit some patients with small kidney stones.”
They stressed that the key is to have a small kidney stone, defined as one that is 4mm or smaller.
"If you know you have a kidney stone and it is smaller than 4mm, [you can try] going on a variety of amusement park thrill rides," Wartinger said, adding that patients whose kidney stones have been broken up using ultrasound can also try the method.
While Wartinger admitted the study needs to be replicated in real kidney stone patients, he believes the results are promising and support the osteopathic philosophy of medicine, which emphasizes prevention and the body's natural healing capabilities.
The two researchers say they now want to try other amusement park rides (for science!), to test their ability to aid in the passage of kidney stones.