Quick Answer
Riding roller coasters might help you pass kidney stones. A study found that sitting in the back car particularly increased the chances of a stone passing. This is fascinating because a thrill-seeking amusement park ride could offer a surprisingly simple, accessible, and enjoyable alternative to more conventional medical treatments for this painful condition.
In a hurry? TL;DR
- 1Ride roller coasters' back carriages for a 64% success rate in passing small kidney stones (under 4mm).
- 2Big Thunder Mountain Railroad at Disney World showed a higher efficacy for kidney stone passage.
- 3The jerky, multidirectional forces of specific roller coasters can act as a mechanical sieve for stones.
- 4Avoid high-intensity coasters with loops, as G-forces can prevent stones from dislodging.
- 5Roller coasters offer a low-cost, fun alternative for naturally passing painful kidney stones.
- 6This 2016 study, awarded an Ig Nobel Prize, highlights mechanical forces as a potential medical solution.
Why It Matters
It's surprising that a fun theme park ride might be a surprisingly effective, low-cost treatment for kidney stones.
Riding a roller coaster can help pass small kidney stones, particularly if the passenger sits in the rear carriage. According to a 2016 study, the back row of a coaster boasts a 64 percent success rate for dislodging stones, compared to just 17 percent in the front.
Key Stats: The Roller Coaster Cure
- Success rate in the back row: 64 percent
- Success rate in the front row: 17 percent
- Optimal stone size: 4 millimetres or smaller
- Primary location of study: Big Thunder Mountain Railroad, Disney World
- Recognition: 2018 Ig Nobel Prize for Medicine
Why It Matters
This research proves that mechanical force and gravity can sometimes solve internal medical issues more effectively than expensive pharmaceuticals. It transforms a leisure activity into a functional, low-cost therapeutic option for a notoriously painful condition.
The Big Thunder Mountain Experiment
The discovery began with a patient who reported passing one kidney stone after each of three consecutive rides on the Big Thunder Mountain Railroad at Disney World’s Magic Kingdom. This was not a fluke; the patient had a history of difficult stones and found the rattling of the coaster more effective than hospital intervention.
Dr David Wartinger and Dr Marc Mitchell from Michigan State University decided to test this anecdote scientifically. They created a 3D-printed synthetic kidney model, complete with three actual kidney stones of various sizes, and tucked it into a padded rucksack.
They took the model on 20 separate rides. They soon discovered that the specific physics of the coaster mattered immensely. The chaotic, multidirectional forces of the ride acted as a mechanical sieve, coaxing the stones through the narrow passages of the renal system.
Gravity vs. G-Force
The study, published in the Journal of the American Osteopathic Association, highlights a counterintuitive reality: more speed is not necessarily better. While high-intensity coasters with loops and inversions might seem more effective, they often involve centrifugal forces that press the stone against the kidney wall.
The researchers found that Big Thunder Mountain—a ride that is relatively jerky and does not go upside down—was the perfect candidate. The back row is more effective because that is where the most significant centripetal force and vibration occur as the train whips around corners trailing the engine.
Practical Applications
For those diagnosed with small stones, a trip to an amusement park could preempt the need for more invasive treatments.
- Preventative maintenance: Taking a ride after lithotripsy can help clear out remaining fragments.
- Cost-effectiveness: A theme park ticket is significantly cheaper than a day in a surgical suite.
- Pre-travel check: Dr Wartinger suggests patients with small stones might want to clear them before holidays to avoid a medical emergency in a foreign country.
Interesting Connections
- Centrifugal Force: Unlike linear acceleration, the jerky side-to-side movement of a mine train coaster mimics the manual manipulation a doctor might use.
- Lithotripsy: This is the standard medical procedure that uses sound waves to break stones; the coaster essentially provides the physical follow-through.
- Ig Nobel Prizes: These awards celebrate research that first makes people laugh, and then makes them think. This study won the Medicine prize in 2018.
Does any roller coaster work?
No. The researchers specifically recommended rides that are bumpy and quick with plenty of lateral movement. Extremely fast, smooth coasters or those with multiple inversions may be less effective because the G-forces are too consistent.
Is this a replacement for medical advice?
No. While the 64 percent success rate is high, this only applies to stones small enough to pass naturally. Always consult a urologist to ensure the stone size is manageable before heading to a theme park.
Why is the back row better?
The back of the coaster train experiences more whip and more intense vibrations as it follows the lead car through turns. This increased kinetic energy is what helps shake the stone loose from the kidney's interior lining.
Key Takeaways
- Back row advantage: Sitting at the rear of the coaster provides nearly four times the chance of passing a stone.
- Mechanical vibration: The success of the ride depends on jerky, multifaceted movements rather than sheer speed.
- Small stones only: This method is specifically for stones 4 millimetres or smaller that are located in the upper kidney.
- Proven science: This started as an urban legend but was validated by Michigan State University researchers using 3D-printed models.
A roller coaster may be the only medical treatment where screams of terror are considered a side effect rather than a symptom. For the millions of people who suffer from kidney stones annually, the back row of a theme park ride is no longer just for thrill-seekers; it is a legitimate seat for recovery.
