Just ask any one of the 300,000 Americans who develop kidney stones: What if the excruciating pain of passing one of those little devils could be prevented by strapping¹ yourself into a make-believe runaway² mine train, throwing your hands in the air and enduring G-forces as high as 2.5 for about three minutes? Would you do it?

从30万患肾结石的美国人中去随便找个患者问问：若乘坐一辆越矿飞车，飞车如逃离般飞驰而过时手在空中乱舞，还要承受高达2.5G的重力三分钟，就能免去排出那些小个恶魔时的剧痛，你会去做吗？

Hell yeah, they’d do it.

废话，他们会的。

In a bit of medical research inspired by strange and remarkable³ patient accounts, a Michigan State University urologist reports that, yes, riding a medium-intensity roller coaster such as the Disney theme parks’ Big Thunder Mountain Railroad can result in the painless passing of small, and even a few large, kidney stones.

密歇根州立大学的泌尿专家注意到了一些罕见病例，受其启发进行了医学研究。他们得出报告说，是的，玩一趟中等刺激的过山车，比如迪士尼乐园的巨雷山过山车，能无痛排出小粒甚至是一些大颗肾结石。

For best results, ride in the back, where — roller coaster afficionados all seem to agree — the thrills are greatest.

坐在过山车尾部效果最佳，过山车爱好者都知道坐在后面的座位是最刺激的。

Independent of kidney stone volume and location, findings reported Sunday in the Journal of the American Osteopathic Assn. showed that sitting in the back of the roller coaster resulted in an average passage rate of 63.89%.

周日发表在《美国骨科协会杂志》上的调查报告表示，坐在过山车尾部平均排石率能达到63.89%。

Front-seat rides resulted in a far more modest passage rate of 16.67%.

而坐在头部，排石率要低得多，只有16.67%。

In what magical kingdom, you may well ask, does someone think to conduct such research?

你完全可以问，得在什么魔法王国才做得出这种实验呢？

Dr David D. Wartinger, a professor emeritus⁴ at Michigan State University’s College of Osteopathic Medicine, initiated⁵ the study after a series of patients reported something almost too strange to believe: In the wake of riding Big Thunder at Walt Disney World in Orlando, Fla., these patients said their kidney stones passed painlessly from the kidney through the narrow duct of the ureter and into the bladder.

密歇根大学骨科医学退休教授大卫•沃汀格尔是研究发起者，之前有肾结石患者向他讲述了桩桩难以置信的怪事：他们在佛罗里达州奥兰多的迪士尼乐园玩了巨雷山过山车后，体内的肾结石就毫无痛感地从肾脏经由狭窄尿管排到了膀胱内。

In one case, a patient told Wartinger that he passed one kidney stone after each of three consecutive⁶ rides on the roller coaster.

有一个案例的病人告诉沃汀格尔，他连着坐了三次过山车，每次都有一颗结石排出。

Using a 3-D printed model of that patient’s kidney, Wartinger and his colleagues implanted three kidney stones of various sizes into the upper, middle or lower passageways of the clear silicone model.

沃汀格尔和同事用3D打印机制造了这位患者肾脏的透明硅胶模型，并把三个大小不一的肾结石放入模型上中下的管道中。

Two of those mineral clusters, which can form as the kidney filters waste from the bloodstream, were small-to-moderate size — 4.5 millmeters and 13.5 mm.

肾结石是肾脏在过滤血流垃圾时形成的矿物质群。其中两颗结石小的4.5mm，中等大小的13.5mm。

Those might pass through the duct leading to the bladder without incident but could also cause considerable pain and discomfort⁷ as they passed unaided.

这等大小的结石在经由尿管向膀胱自然移动时，可以平安无事，但也能引起剧痛和不适感。

But a third measured 64.6 mm, a size that would rarely pass without treatment — the administration of ultrasound shock waves, called lithotripsy, designed to break up the deposit and allow it to pass.

第三颗结石64.6mm大，这种大小的结石只有借助超声冲击波治疗，也即碎石术打碎结石，才能排出体外。

The researchers received permission from Walt Disney World first, then concealed⁸ the kidney model in a backpack and rode Big Thunder 20 times, varying their seat position between front and back.

实验前，研究人员先征得了迪士尼乐园同意，然后把肾模型藏到背包中坐了20次巨雷山过山车，期间还变换位置，从头部换到尾部。

After analyzing⁹ the location of those three kidney stones at the end of each ride, the researchers concluded that findings support the anecdotal evidence that a ride on a moderate-intensity roller coaster could benefit some patients with small kidney stones, Wartinger said.

研究人员在每次坐完过山车后都会检查三颗肾结石的位置，得出了如下结论。

When the kidney stone was large, the initial position of the kidney stone affected¹⁰ the likelihood of its passing during the ride.

沃汀格尔说，我们实验所得验证了病人所述情况，坐中等刺激的过山车可以帮助一些患者排出小块结石。

But even those passed two in three times while the silicone model rode the thrill ride.

大颗肾结石所处位置会影响坐过山车时结石排出的可能性，但排出结石时三次有两次是在硅胶模型经过刺激车程的时候。

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 calculi¹¹, wrote Wartinger and co-author Dr Marc A.

很多美国人住在一家游乐园几小时车程内，这家游乐园有一辆过山车可以帮助人们排掉肾盏结石，沃汀格尔和来自华盛顿州波尔斯波医生诊所的马克•米切尔一同写道。

Mitchell of the Doctor’s Clinic in Poulsbo, Wash.Roller coaster therapy might be a good preventive treatment for people who are high risk of developing obstructive kidney stones, wrote Wartinger and Mitchell.

过山车疗法对梗阻性肾结石易患人群可能是个很好的预防疗法，沃汀格尔和米切尔在报告中说。

They suggested that patients who have had kidney stones in the past, or women who have had kidney stones and are thinking of becoming pregnant, consider a thrill ride or two in a bid to clear tiny stones before the deposits grow larger.

他们建议过去长过肾结石的患者和有肾结石、正在准备开始妊娠的女性，考虑放开胆子坐一两次过山车来把微小结石清出，以防长得更大。

Kidney stone sufferers who have had their deposits broken up by lithotripsy might also consider a roller-coaster ride to finish the job, they said.

他们还说，已接受过碎石术治疗的肾结石患者也可以考虑坐过山车，以把结石彻底排出体外。