Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
×
Science

Researchers Show Parachutes Don't Work, But There's A Catch (npr.org) 185

Reader Beeftopia shares a report: Research published in a major medical journal concludes that a parachute is no more effective than an empty backpack at protecting you from harm if you have to jump from an aircraft. But before you leap to any rash conclusions, you had better hear the whole story. The gold standard for medical research is a study that randomly assigns volunteers to try an intervention or to go without one and be part of a control group. For some reason, nobody has ever done a randomized controlled trial of parachutes. In fact, medical researchers often use the parachute example when they argue they don't need to do a study because they're so sure they already know something works. Cardiologist Robert Yeh, an associate professor at Harvard Medical School and attending physician at Beth Israel Deaconess Medical Center, got a wicked idea one day. He and his colleagues would actually attempt the parachute study to make a few choice points about the potential pitfalls of research shortcuts.

They started by talking to their seatmates on airliners. [...] In all, 23 people agreed to be randomly given either a backpack or a parachute and then to jump from a biplane on Martha's Vineyard in Massachusetts or from a helicopter in Michigan. Relying on two locations and only two kinds of aircraft gave the researchers quite a skewed sample. But this sort of problem crops up frequently in studies, which was part of the point Yeh and his team were trying to make. Still, photos taken during the experiment show the volunteers were only too happy to take part. The drop in the study was about 2 feet total, because the biplane and helicopter were parked. Nobody suffered any injuries. Surprise, surprise. So it's technically true that parachutes offered no better protection for these jumpers than the backpacks.

This discussion has been archived. No new comments can be posted.

Researchers Show Parachutes Don't Work, But There's A Catch

Comments Filter:
  • This (Score:5, Insightful)

    by Anonymous Coward on Sunday December 23, 2018 @04:07PM (#57850166)

    is the dumbest fucking thing I've read today.

    • by Anonymous Coward

      I hope no one spent any research money on this stupid crap. If so, there should be real consequences.

    • Re:This (Score:5, Insightful)

      by Zocalo ( 252965 ) on Sunday December 23, 2018 @04:17PM (#57850214) Homepage
      And from this I can conclude that either you did not actually read it, failed to comprehend what you read, or (just possibly) really took issue with how they presented their point, despite the Christmas issue of BMJ being intentionally lighthearted.

      Hint: this has nothing to do with people jumping out of planes and everything to do with the extent that medical researchers assume things are so rather than actually demonstrate that is the case.
      • Re:This (Score:5, Interesting)

        by ceoyoyo ( 59147 ) on Sunday December 23, 2018 @04:44PM (#57850344)

        "medical researchers assume things are so rather than actually demonstrate that is the case."

        I disagree. The authors of this study went out of their way to get a null result. You don't do that in real life, because you won't get published. You might be tempted to go out of your way to get a *positive* result. The main point of the article is that medical *practitioners* (also journalists, the public, administrators) read a summary, skip the details, and make undue assumptions.

        The conclusion of the paper has a bit of an odd line:

        "When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice."

        In my experience, it's usually the opposite. Large RCTs are usually sponsored by pharma companies, and they craft inclusion criteria to give the greatest chance of finding an effect. The results are valid, in the population studied, but it's very easy for end users of the research to generalize that to "X is effective for treating Y."

        • Re: This (Score:4, Insightful)

          by jd ( 1658 ) <imipak @ y a h o o.com> on Sunday December 23, 2018 @04:53PM (#57850386) Homepage Journal

          Frozen salmon have brain activity, according to research winning an Ignobel prize in its demonstration of poor controls and poor statistical analysis in fMRI studies.

          So, yes, null results are published and are valuable, when they show up flawed methodology.

          • by ceoyoyo ( 59147 )

            The paper you're referring to was another satirical one, illustrating how easy it is to make mistakes with fMRI analyses and get false *positive* results (dead fish respond to emotional stimuli). I'm not sure how that supports your contention that null results are routinely published.

            It's very difficult to show flawed methodology by producing a null result. It's much easier to demonstrate a false positive, as in the salmon study.

        • Re:This (Score:5, Interesting)

          by rtb61 ( 674572 ) on Sunday December 23, 2018 @10:29PM (#57851540) Homepage

          I know exactly that kind of example, used in real life and trumpeted all over the place by corporate main stream media, backed by professionals (true scumbags of course) and paid for by certain corporations. The sugar rush saga, where a bunch of exceedingly corrupt doctors proved sugar rush does not exist and corporate media spread it around and you can fucking guess who paid for it. The missing fact, that was in the research but not mentioned by entirely corrupt corporate main stream media, the sugar consumption was part of a properly balanced diet and never exceeded recommended calorie intake, nothing fucking what so ever like a bunch of children eating every sugary thing in sight at a party and then going nuts and collapsing sometime there in after. Done on purpose, with an air of impartiality but entirely cooked up from the get go, by professionals who should have been pilloried, tarred and feathered and driven out of the community, all paid for by junk food companies. Yep they do it, all the fucking time and this little story is just an example of their example, how one single fact left out on purpose can distort the entire outcome and done on purpose.

          They should have refereed to the sugar rush fraud as a example of this kind of corruption of science.

      • by gweihir ( 88907 )

        Indeed. This whole thing is about as ingenious as https://blogs.scientificameric... [scientificamerican.com], perhaps more so as it is even more obvious. It takes some actual insight and common sense to see that though. Sadly, both are rare and not correlated to intelligence and education.

      • The article was going on about how it was a counterpoint to the medical community's set of treatments for which they believe a trial is not necessary because you "wouldn't create a trial on the necessity of parachutes." A trial like that would be impossible to conduct and unethical.

        So, here they conducted one.

        It's strange because it *supports* the point that not only could you not conduct a trial on the necessity of parachutes, but you can abuse the system to create a trial where you can demonstrate the i

      • Except it DOESN'T.
        I fully get the point of the article, but the example is just sophomoric semantics: do parachutes make you safer jumping from airplanes? "No!" claim the "researchers" feeling they've proved something meaningful...only if they dismiss the always-implied language "airplanes....ACTUALLY FLYING IN THE AIR AT A MEANINGFUL HEIGHT AND SPEED".

        It would be as stupid as someone claiming that putting strychnine into your breakfast wouldn't kill you (because they never said you actually ATE the food!),

    • Re:This (Score:5, Insightful)

      by MikeDataLink ( 536925 ) on Sunday December 23, 2018 @04:19PM (#57850222) Homepage Journal

      is the dumbest fucking thing I've read today.

      Then you quite simply do not understand the point of it smarty pants.

      At 2ft the parachute provided no better protection than an empty backpack. This is a silly of course, but the point is that in medical research when shortcuts are taken they miss the point and come to a conclusion like this on something that actually DOES matter.

      It's an analogy to help the layman understand. Get with the program.

      • It's an analogy to help the layman understand.

        I am a layman, and what I understand from this experiment is that the obvious assumption (that you don't need a chute for a two foot drop) is the correct one, and that no experiment was necessary to prove it.

        This is the exact opposite of what they intended to show.

        It may be true that "obvious" assumptions can be wrong, but this experiment certainly does not show that.

        • (that you don't need a chute for a two foot drop)
          If you are a snowflake: no
          If you are a human: no
          If you are fragile champaign glass: perhaps!

          It may be true that "obvious" assumptions can be wrong, but this experiment certainly does not show that.
          This experiment shows that every experiment can be stretched to an absurd level, and if there is no meta research into it, the conclusions are wrong or misleading.

      • I already have a backpack, but I do not have a parachute. So I'd take the parachute!
    • is the dumbest fucking thing I've read today.“

      You have no instinct for science.

      • by novakyu ( 636495 )

        Yeah. Even dumber things happen "in science." At least these authors knew they were doing a dumb thing.

    • Re:This (Score:5, Funny)

      by perpenso ( 1613749 ) on Sunday December 23, 2018 @05:38PM (#57850578)

      is the dumbest fucking thing I've read today.

      It seems you don't use twitter :-)

    • And here's the dumbest fucking thing [youtube.com] you'll watch today.

    • is the dumbest fucking thing I've read today.

      The sad part is all the dumbest things you don't realize you've read, which was the point of this "study." The overwhelming majority of studies have substantial flaws with the design of the underlying experimental methodology employed, but it's much more difficult to point those out to people after reading them because people tend not to take in the experimental method, the ideas leading up to it, the underlying theories, the engineering nuances of the different components involved, and the characteristics

    • is the dumbest fucking thing I've read today... except I didn't read it or even bother reading the summary. I just read the title of the summary and jumped to a conclusion.

      FTFY

    • by twebb72 ( 903169 )

      is the dumbest fucking thing I've read today.

      Side effects include: chafing, heart palpitations, eye dryness, dry mouth, back sweat. Use only in well-ventilated area. Pregnant women, the elderly, and children should avoid use. Do not use this product if you have high blood pressure, heart disease, asthma, glaucoma, or difficulty with bladder function. Most serious side effects include loss of bowel control, paralysis, and death

      Dumber?

    • Not necessarily.
      I think it is a good point that not all things can be safely studied and evaluated. Because of the morality of such choices.
      For example Animal Testing. Different animals react differently to drugs, there could be a safe drug that cures a deadly illness in humans, that would just kill a rodent. But we cannot start testing on humans especially if shown would kill a rodent.
      Proper science without the bonds of ethics, would jump straight to people and see what the results are. Pushing a person fr

    • by Toad-san ( 64810 )

      Agree, totally agree. I was a bit dubious, being a career Airborne / SF Jumpmaster qualified NCO with maybe 150 jumps, maybe 10 freefall / skydiving. But to save "the drop was about two feet total" for last? Bogus.

  • by johnpagenola ( 601936 ) on Sunday December 23, 2018 @04:09PM (#57850176)
    My favorite study along these lines was a randomized selection of men, half of whom were injected with steroids and half got no steroids. Neither group showed muscle gains during the study period. Not mentioned in the headline was that neither group lifted weights or engaged in any exercise. So in a sense the headline was true: just taking steroids doesn't give you big muscles. But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.
    • by Okian Warrior ( 537106 ) on Sunday December 23, 2018 @05:44PM (#57850586) Homepage Journal

      My favorite study along these lines was a randomized selection of men, half of whom were injected with steroids and half got no steroids. Neither group showed muscle gains during the study period. Not mentioned in the headline was that neither group lifted weights or engaged in any exercise. So in a sense the headline was true: just taking steroids doesn't give you big muscles. But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.

      My favorites are medical studies on vitamins and supplements and other related.

      For example, a 4-week study of Glucosamine/Chondroitin supplements that had no effect on joint pain of Rheumatoid Arthritis patients.

      Conclusion? G/C supplementation has no effect.

      Reality? We don't really know. 1) G/C supplementation is to make stronger and healthier joints by supplying building blocks not otherwise found in the diet, and 2) Joints have no blood vessels, so change very slowly. Typically 7 weeks or more would be needed to see an effect.

      Compare with: St. John's Wort depression studies lasting less than 4 weeks (medical depression meds sometimes take as much as 6 weeks to show an effect), Omega 3 fatty acid supplementation studies in healthy adults (instead of children/adults with behavioral issues), and so on.

      Nutrition studies are particularly useless. My favorite example is the guy making Soylent started out by asking the simplest question: what nutrients do we actually need to be healthy?

      The answer is: No one knows, the literature is a bewildering mess of confusing and contradictory results, and nutrition experts have differing views.

      (If you don't believe me, see if you can determine a) the *minimum* amount of vitamin D needed daily to prevent disease, and b) the *optimum* amount needed for best health. Bonus points if you can determine whether mega doses of Vitamin D are toxic. Supplemental bonus points if you can determine whether mega doses of Iodine are toxic.)

      • by Kohath ( 38547 )

        How many points do I need to earn before I qualify for a parachute?

      • Great, now they're going to have to re-run the study, taking into account the individual's diet and medications before strapping on the backpack/parachute.

    • But the guys in my gym who took steroids got big because they were able to recuperate faster from heavier workouts.
      Steroids don't work that way.

      • Yeah, they do. That's one of the primary reasons people trying to gain a lot of muscle mass use them. Anabolic steroids directly impact cell metabolism, allowing them to produce/use ATP more rapidly. This means they heal faster and recharge faster, allowing gym rats to work out more often and much more aggressively than they otherwise would be able to.

        • The parent said: steroids allow to recover faster from exercise. And that is plain wrong.
          ATP production has nothing to do with healing anyway ...

          allowing gym rats to work out more often and much more aggressively than they otherwise would be able to. Wrong.

          Steroids simply speed up muscle growth. There is no other effect. You can spent the same time in a gym without them, and if you train smart you have the same muscle grows, just slower. The main limiting factor is protein digesting/conversion anyway.

  • ....just guess.
    • IgNobels have been issued for this sort of work before - fish in brain scanners, anyone?

      I'd be horrified if they awarded another for what is basically repeat work.

    • by AmiMoJo ( 196126 ) on Sunday December 23, 2018 @05:10PM (#57850470) Homepage Journal

      This wasn't a serious study, it is actually an extension of an old joke.

      https://www.bmj.com/content/32... [bmj.com]

      They are mocking people who demand double blind tests of everything and dismiss anything that isn't tested that way. Since double blind trials are impossible for many things in medicine, especially psychology and sociology, some people think they are bunk yet probably wouldn't hold parachutes to the same rigorous standard.

      • Except this analogy falls flat on its face because they could easily do a double-blind study like this. They just couldn't use humans. Everything about this study would be 100% applicable to humans if they used a dummy instead. We know this, because we understand how physics works at this scale.

        That's not true in medicine, psychology, or sociology.

        The dead fish fMRI study was far more insightful than this, because there, at least, it wasn't something that any 8 year old could test. It also didn't involve pr

        • by AmiMoJo ( 196126 )

          That's the point, there are in fact ways of testing these ideas indirectly or by proxy, and many of them are well proven e.g. CBT. Still, every time there is a discussion about mental health on Slashdot, someone will demand proof that depression is real and that widely used therapies actually work, citing a lack of double blind testing as evidence that it's all just bunk.

    • ....just guess.

      It's a pretty big leap from that study to an IgNobel...

  • This first test involves something the lab boys call 'repulsion gel.' You're not part of the control group, by the way. You get the gel. Last poor son of a gun got blue paint. Hahaha. All joking aside, that did happen â" broke every bone in his legs. Tragic. But informative. Or so I'm told. --Cave Johnson

    Meanwhile, the researchers didn't produce anything new, similar "research" was done in the past [slashdot.org] where researchers didn't know how strings worked in Java.

    • Ah, but those previous researchers didn't know what they were doing. These parachute researchers did know, and they were intentionally pointing out flaws in many studies in a humorous way.

  • by Gravis Zero ( 934156 ) on Sunday December 23, 2018 @04:19PM (#57850220)

    For some reason, nobody has ever done a randomized controlled trial of parachutes.

    It would be unethical to send people to their certain deaths when gravity has been sufficiently tested to the point where it is accepted as a physical constant.

    However, I'm sure ethicists would be willing to look the other way if all idiots complaining about a lack of controlled trial were used as the subjects of such a test.

    • by Sigma 7 ( 266129 )

      There's still other ways of doing tests without sending people into harm's way. Automobile crash tests have often used crash test dummies rather than live persons, and I'm sure parachute drop tests can do the same as well.

      Easiest way is to purchase a force sensor that works for impacts.

    • It would be unethical to send people to their certain deaths when gravity has been sufficiently tested to the point where it is accepted as a physical constant.

      Gravity is just a theory man.

      • by pjt33 ( 739471 )

        You shouldn't personify gravity. It doesn't like it.

    • by jd ( 1658 ) <imipak @ y a h o o.com> on Sunday December 23, 2018 @04:59PM (#57850424) Homepage Journal

      Why would you send people?

      Crash test dummies loaded with sensors would give you much more information.

  • In the Rama story, a group of people jumped from a cliff into water, using their clothes as a braking mechanism.

    I've actually calculated this; and it COULD work.

    I won't be trying it unless there's no other option, but it goes like this:

    Terminal velocity in the atmosphere is ~120mph in a "Spread Eagle" orientation, about 180mph in a pike position.

    Hitting water at 180 will spatter you, but 120mph is right at the edge of what's possible; the guys that cliff dive are going close to that speed.

    Hitting the water

    • It was actually just one guy. And he wasn't using his clothing to brake his descent. He was using it to stabilize his descent so that he would hit the water feet-first with his legs crossed. Also, if I recall correctly, Rama did not spin fast enough to produce a full Earth gravity at even the lowest level of the cylinder. And the plot point was that the jumper had crashed after flying down the zero-g axis of Rama to explore the top of an otherwise unscalable mesa (And, therefore, would be under even les

      • Yeah it was 0.6g and > 1 earth atmosphere so terminal velocity was survivable.

        Terminal velocity on Earth is 200 km/h, but I do wonder about using a small drag parachute to cut your speed at impact.

    • Arthur C Clarke, not Asimov.

      And, yes, it's all about terminal velocity for a given aerodynamic configuration.

    • That's a lot these days. :D

      And no one called me out for misspelling Asimov. (You did spell it correctly above, tho.) :)

      I'd definitely give it a shot, if I were falling from a plane, gravity difference or not; you KNOW what happens without trying it, lol.

      Mythbusters broke Buster into pieces dropping him from a crane, trying the 'break the surface tension with a hammer" thing.
      But he landed pretty badly off axis, so IDK.

    • by Greyfox ( 87712 ) on Sunday December 23, 2018 @10:39PM (#57851586) Homepage Journal
      120...ish. I fall closer to 130. I might be able to slow down to 120, but it takes some work on my part. The fastest speed on my digital altimeter is 205 mph, attained in a very steep dive at 9000 feet. I leveled into a track shortly after that, since opening a parachute at 205 mph would kill me just about as fast as not opening a parachute at 205 mph. Some of the kids I've seen flying in the wind tunnel fall at 70-80 mph. If you weigh less than 90 pounds and know how to fall slowly, I reckon you might be able to survive a terminal velocity fall if you land on the right surface. If you can find a surface that doesn't shatter some bones in the process, that'd actually be a fun party trick.
    • by Mal-2 ( 675116 )

      Also, if you can steer for the white water in the wake of a boat, you may not have to take the full brunt of hitting the water. I'm sure it would scare the shit out of the people on that boat though, as it would almost certainly appear you were attempting to land on them.

  • The takeaway (Score:4, Insightful)

    by Rick Schumann ( 4662797 ) on Sunday December 23, 2018 @05:08PM (#57850462) Journal
    If someone doesn't inherently understand what the real takeaway from this story is, then I question their IQ, their capacity to think critically, or both.
    • They went to all this trouble to tell people that bad experiment controls yield bad results?

  • Scientists do not only have a duty to perform good research (many do not, sadly), but also to inform the general public about the meaning of their results. This study is perfectly valid (if scientifically worthless) and nicely demonstrates that an experiment or study may not imply the things a non-expert may think it does. As such, it serves as a nice warning. Another one about as ingenious is this one here: https://blogs.scientificameric... [scientificamerican.com]

    I hope that this study wins an IgNoble as well. Note that the IgNob

  • by RhettLivingston ( 544140 ) on Sunday December 23, 2018 @06:37PM (#57850792) Journal

    I mean, unless I've missed it, there doesn't seem to be any post here thinking about how to make this "true".

    Sure, the study was ridiculous and intended to make a unrelated point, but the nerds should be focusing on the fact that there have been survivors of high falls without parachutes. So the most important barrier to serious R&D has been broken - the possibility is provably there!

    In looking at many of the accounts on the web of high falls, I have to discount those that had parachutes that didn't open properly or were likely within the wreckage of an aircraft for most of the fall. Those were likely slowed down by things like the drag of a defective parachute or the body of a plane.

    The more intriguing accounts are the falls from high buildings. In most cases, they seem to have been helped by landing on something that absorbed some of the shock of landing. Several landed on roofs. A very intriguing one landed on the roof of a car after a fall of 22 stories and "walked away" with only a broken elbow.

    One can imagine that these folks likely benefited from some combination of positioning their bodies for high drag and/or maneuvers that translated vertical speed to horizontal speed that was bled off by traversing more air distance and landing in some particular way on a surface that absorbed a lot of the shock.

    So how might a compact device that could be carried at all times enhance the possibility of surviving something like this?

    A smartphone app could detect the freefall as well as that it is still on the person. If connected to cameras around the area it might be able to spot the best surface to hit. Guiding the arms and legs of the person to positions that will fly them toward that while minimizing downward airspeed would be problematic. That would seem to require either an exoskeleton (maybe a soft motor one) built into clothing or some muscle control interface like those being experimented with on paralyzed people. So that's a stretch today. As for having to find a roof or car to hit, that might be made less necessary with something like a personal explosive airbag and some means of ground proximity detection.

    It is an interesting rabbit trail that could have application in something like the construction industry, as a failsafe for climbers, military, etc.

    • "A smartphone app could detect the freefall as well as that it is still on the person. If connected to cameras around the area it might be able to spot the best surface to hit. Guiding the arms and legs of the person to positions that will fly them toward that while minimizing downward airspeed would be problematic. That would seem to require either an exoskeleton (maybe a soft motor one) built into clothing or some muscle control interface like those being experimented with on paralyzed people. So that's a
  • it is the same with a lot of testing and reviews when published. everything you read is so bias these days so you never get the whole picture.

  • This story reminds me of the old joke about the scientists who proudly announced that their experiments proved that dogs and cats could live underwater ... just not very long.

    • "Scientists report that scientists did studies on monkeys to see if monkeys would make good scientists. Its not all good news, though, some scientists will be out of a job... Unless, of course, they happen to be monkeys."

      (delivery is important)
      "SCIENTISTS report that SCIENTISTS did studies on MONKEYS to see if MONKEYS would make good SCIENTISTS. Its not all good news, though, some SCIENTISTS will be out of a job... Unless, of course, they happen to be MONKEYS."

  • I'll just miss the point the other way around, and point out that they could've got usable data by using crash test dummies. And indeed, observational studies of people who fell without parachute vs. those who fell with would easily point both the expected safety benefits and the folly of running a controlled trial. This same problem exists for a lot of automotive safety issues (Not that there aren't a LOT of willing people to test not using a helmet on bike, seatbelt on car etc. but studies don't just hurl

  • by colinwb ( 827584 ) on Sunday December 23, 2018 @07:32PM (#57850992)

    Since some commenters appear to have misunderstood the point of the article it's worth quoting from the BMJ paper [bmj.com] (I recommend actually reading the entire paper and/or this BMJ blog [bmj.com]):

    ...

    The study also has several limitations. First and most importantly, our findings might not be generalizable to the use of parachutes in aircraft traveling at a higher altitude or velocity. Consideration could be made to conduct additional randomized clinical trials in these higher risk settings. However, previous theoretical work supporting the use of parachutes could reduce the feasibility of enrolling participants in such studies.

    ...

    Finally, although all endpoints in the study were prespecified, we were unable to register the PARACHUTE trial prospectively. We attempted to register this study with the Sri Lanka Clinical Trials Registry (application number APPL/2018/040), a member of the World Health Organization’s Registry Network of the International Clinical Trials Registry Platform. After several rounds of discussion, the Registry declined to register the trial because they thought that “the research question lacks scientific validity” and “the trial data cannot be meaningful.” We appreciated their thorough review (and actually agree with their decision).

    The PARACHUTE trial satirically highlights some of the limitations of randomized controlled trials. Nevertheless, we believe that such trials remain the gold standard for the evaluation of most new treatments. The PARACHUTE trial does suggest, however, that their accurate interpretation requires more than a cursory reading of the abstract. Rather, interpretation requires a complete and critical appraisal of the study. In addition, our study highlights that studies evaluating devices that are already entrenched in clinical practice face the particularly difficult task of ensuring that patients with the greatest expected benefit from treatment are included during enrolment.

    ...

  • I can already see some stable genius out there using this study to defund parachutes in the military
  • This is why you shoot a man before throwing him out of an airplane.

  • Let me guess: it was either psychologists or nutritionists.

  • This isn't just about scientific method or research publication; taken as a larger whole for language in general, it shows that context is king, and the half truth can be more misleading than an outright lie.
    Language is easy to manipulate.

  • Companies will uses the psychology experiment as an excuse to make things less safe.
  • Did they really get funding? They should have been fired on the spot for even suggesting a test like this. Now, let's do the real test and get the plane up in the air, and let's see which one protects you better.. Any volunteers? maybe the researchers who did this 'research' as they are so confident the backpack will protect them just fine....

Experience varies directly with equipment ruined.

Working...