Roller coasters can rid riders of renal calculi, researchers reveal
Key Takeaways
Riding moderate-intensity roller coasters can prompt patients to pass small kidney stones, according to a report published in the October 2016 issue of The Journal of the American Osteopathic Association. Sitting at the rear of the roller coaster doubles the likelihood of passing a stone, researchers found.
The researchers started this study after different patients had recounted passing kidney stones following a ride on a specific Disney World roller coaster.
“Over several years, a notable number of our patients reported passing renal calculi spontaneously after riding the Big Thunder Mountain Railroad roller coaster at Walt Disney World’s Magic Kingdom theme park in Orlando, Florida,” the authors wrote. “One patient reported passing renal calculi after each of 3 consecutive rides on the roller coaster.”
The number of these stories was enough to raise their suspicions of a possible link between riding roller coasters and passing kidney stones.
To investigate, the researchers used a silicone cast model of a kidney created on a 3-D printer. The model held 3 actual calculi of various sizes (4.5 mm3, 13.5 mm3, and 64.6 mm3) suspended in urine and positioned in the upper, middle, or lower calices of the kidney.
The researchers, who had permission from the theme park, kept the kidney model concealed in a backpack during 20 rides on the Big Thunder Mountain Railroad roller coaster. Afterward, the researchers analyzed those 60 ride outcomes to determine how variables of kidney stone size, location in the kidney, and position in the roller coaster (front seats vs. rear seats) affected passage of the kidney stones.
“Preliminary study findings support the anecdotal evidence that a ride on a moderate-intensity roller coaster could benefit some patients with small kidney stones,” said study leader David D. Wartinger, DO, JD, currently Professor Emeritus of Urology at Michigan State University College of Osteopathic Medicine, in East Lansing, MI.
Independent of calculi size and calyceal location, the findings showed that sitting in the back of the roller coaster resulted in a passage rate of about 64%, while riding in the front seat resulted in a passage rate of nearly 17%.
When sitting in the rear seats, passage rates differed due to calyceal location but independent of calculi size, with a 100% passage rate from the upper calyx, a 55.6% passage rate from the middle calyx, and a 40% passage rate from the lower calyx, the researchers found.
“Roller coaster riding may offer patients an entertaining as well as preventive and therapeutic option to medication, dietary restriction, and further surgery,” Dr. Wartinger explained in this video, in which he describes the study and its results.
The mechanisms behind how a roller coaster can help to pass kidney stones have yet to be determined, the researchers noted. They cautioned that this study only investigated small calculi; patients with renal calculi large enough to cause ureteral obstruction or significant renal colic may want to avoid the kinds of external forces caused by roller coasters, the researchers added. “Passing a kidney stone before it reaches an obstructive size can prevent surgeries and emergency room visits,” Dr. Wartinger advised.
“Roller coaster riding after treatments like lithotripsy and before planned pregnancies may prevent stone enlargement and the complications of ureteral obstruction,” he added.
Interestingly, Dr. Wartinger said that passing a kidney stone with the aid of a roller coaster demonstrates a core principle of osteopathic medicine.
“The osteopathic philosophy of medicine emphasizes prevention and the body’s natural ability to heal,” he explained. “What could be more osteopathic than finding a relatively low-cost, non-invasive treatment that could prevent suffering for hundreds of thousands of patients?”