Medical research is full of twists and turns, but a new study has taken a more literal approach. Researchers report how riding moderate-intensity roller coasters might aid the natural passing of small kidney stones, reducing the need for surgical treatment.

[Big Thunder Mountain Railroad at Walt Disney World in Florida]Share on Pinterest
Using a 3-D-printed kidney model, researchers found riding the Big Thunder Mountain Railroad at Walt Disney World may aid the passing of small kidney stones.
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Study co-author Dr. David D. Wartinger, a professor of neurology at the College of Osteopathic Medicine at Michigan State University, and colleagues publish their findings in The Journal of the American Osteopathic Association.

Kidney stones are one of the most common urinary tract disorders in the United States. They accumulate from substances found in the urine – such as calcium, oxalate, and phosphorus – which can become highly concentrated and form solid masses.

According to the National Institute of Diabetes and Digestive Kidney Disease (NIDDK), kidney stones are the cause of more than 1 million visits to healthcare providers in the U.S. every year, as well as around 300,000 emergency department visits.

Kidney stones vary greatly in size, and they can either remain in the kidney or travel through the urinary tract. Small kidney stones may naturally pass through the urine, often causing little or no pain. Larger stones, however, may become stuck in the urinary tract, which can obstruct urinary flow and cause pain or bleeding.

If kidney stones do not pass naturally, they can grow in size, causing more pain and increasing the need for surgical removal.

Patients with small kidney stones are normally told to drink plenty of water to encourage natural passing, though this does not always work. The new study suggests there may be an alternative for patients who can stomach roller coasters.

Inspiration for the study came from patient reports that a certain ride at Walt Disney World in Orlando, FL – the Big Thunder Mountain Railroad – facilitated the passing of small kidney stones.

According to Dr. Wartinger and team, one patient said he passed a kidney stone after each of his three successive turns on the roller coaster.

To test whether the roller coaster does encourage the natural passing of kidney stones, the researchers used 3-D printing to create a model kidney, which they filled with urine and three kidney stones of different sizes.

After getting permission from Walt Disney World, the researchers placed the kidney model in a backpack and wore it during 20 rides on the Big Thunder Mountain Railroad. They assessed how the roller coaster affected the movement of the kidney stones after each turn.

Sitting at the back of the roller coaster resulted in a 63.89 percent passage rate, the researchers found, while sitting at the front of the roller coaster led to a 16.67 percent passage rate, regardless of size and location. Passage rate refers to the natural passing of kidney stones through the urinary tract.

Explaining the mechanism by which roller coasters may encourage the passing of kidney stones, Dr. Wartinger told Medical News Today that the “significant and random forces jar the stone loose, thus guiding the stone through the passage way.”

“A kidney looks like a tree with branches. The forces move the stone from being positioned where a leaf is located, down through the branches and out through the trunk – and onward to the bladder,” he added. “It’s not surprising that the model we used passed kidney stones on this coaster because it’s based on a gentleman that passed three stones on this exact roller coaster.”

Dr. Wartinger says these early results suggest a moderate-intensity roller coaster ride has the potential to benefit some patients with small kidney stones, but it may not be the right approach for everyone.

“We believe this can be replicated but not everyone will respond to the same ride,” he told MNT. “What’s important to understand is kidney passage patterns are like fingerprints, so each person is going to have their own ideal roller coaster ride.”

Still, he and his team believe their findings certainly warrant further investigation, and they plan to test more kidney models and different sizes of kidney stones on a variety of roller coasters.

Passing a kidney stone before it reaches an obstructive size can prevent surgeries and emergency room visits. Roller coaster riding after treatments like lithotripsy and before planned pregnancies may prevent stone enlargement and the complications of ureteral obstruction.

The osteopathic philosophy of medicine emphasizes prevention and the body’s natural ability to heal. What could be more osteopathic than finding a relatively low-cost, noninvasive treatment that could prevent suffering for hundreds of thousands of patients?”

Dr. David D. Wartinger

Learn about the causes, symptoms, and treatments for kidney stones.