Kidney stones are no fun—but a potential new treatment for them might be. It turns out riding a roller coaster may help people shake small stones loose, according to a new study by two physicians who took their research to Disney World.
Their paper, which was published in The Journal of the American Osteopathic Association, was an attempt to corroborate reports from “a notable number” of patients over the years who said they passed kidney stones within hours of riding Disney's Big Thunder Mountain Railroad. One patient even said he passed three stones, one each after three consecutive rides.
So the researchers used a 3D printer to create a silicone replica of that patient’s kidney, filled it with urine and three kidney stones of varying sizes, and traveled to Orlando to test out the claim themselves. With permission from the park, they rode the Big Thunder Mountain Railroad roller coaster 20 times (oof), keeping the model kidney with them in a padded backpack. They checked the kidney after each ride, and analyzed the outcomes to determine the likelihood of the stones’ passage.
They found that sitting in the back of the roller coaster resulted in a successful passage rate of 63.89%, while front-seat rides delivered a 16.67% success rate. Although their findings are preliminary, co-author David Wartinger, DO, said in a press release, they “support the anecdotal evidence that a ride on a moderate-intensity roller coaster could benefit some patients with small kidney stones.”
“Passing a kidney stone before it reaches an obstructive size can prevent surgeries and emergency room visits,” said Dr. Wartinger, a professor emeritus at Michigan State University College of Osteopathic Medicine. That could have significant impact, considering that more than 300,000 Americans seek emergency care each year for the tiny but painful mineral deposits, made up mainly of calcium crystals, that accumulate in the kidneys. Approximately 11% of men, and 6% of women, will experience them in their lifetime.
Riding a roller coaster after a treatment like lithotripsy (in which ultrasound is used to break large kidney stones into smaller pieces) may help facilitate passage of the deposits, the authors wrote, and may help prevent recurrence in people who’ve had stones in the past. Women with small kidney stones who plan to get pregnant might also consider such an approach, since they can cause complications during pregnancy.
This isn’t the first time such an unconventional treatment for kidney stones has been proposed; the authors note in their paper that spontaneous stone passage has been associated with bungee jumping, roller-coaster riding, and other external applications of force anecdotally in the foreign press. This, however, is the first study of its kind to be published in a peer-reviewed medical journal.
Big Thunder Mountain Railroad is a steel-railed coaster whose cars travel at a maximum speed of 35 miles per hour around sharp turns and quick drops. (It does not go upside down.) The researchers say their results should be replicated on other types of rides—ideally with human participants—before they can make broad recommendations.
They also caution that kidney stones larger than 6 millimeters in diameter only have about a 1% chance of passing without medical intervention—and that people diagnosed with stones that large might want to avoid these types of external forces, to reduce the risk of pain and urinary-tract obstruction.
“Many people in the United States probably live within a few hours’ drive of an amusement park containing a roller coaster with features capable of dislodging calyceal renal calculi,” the authors wrote, using the technical name for kidney stones. “However, physicians and their patients should consider renal calculi location and size as well as medical history.”
Many questions about this potential treatment remain, but Dr. Wartinger is optimistic about future research on the topic. “The osteopathic philosophy of medicine emphasizes prevention and the body’s natural ability to heal," he said. “What could be more osteopathic than finding a relatively low-cost, non-invasive treatment that could prevent suffering for hundreds of thousands of patients?”