For the last of our IgNobel coverage, we turn (heh, turn, you'll see) to the IgNobel prize in Physics, which examined the dizziness is discus throwing, as compared to hammer throwing.
I don't know about you, but when I think of throwing the discus or hammer, I always think of the scene from Roald Dahl's book "Matilda", where the evil headmistress sweeps a girl up by her pigtails, and uses her as a throwing hammer.
One thing you'll note from the quote (aside from the awfulness of, you know, throwing a girl by her hair) is that the headmistress never got DIZZY. It turns out that hammer throwers DON'T get dizzy, pretty much ever (after training, anyway) while discus throwers do, and continue to get dizzy no matter how many years they train. Since the two sports are so similar, the scientists behind this study couldn't help but wonder WHY.
Perrin et al. "Dizziness in discus throwers is related to motion sickness generated by spinning" Acta Otolaryngologia, 2000.
There's a lot of…stuff… that goes in to keeping your balance. Especially while moving. You wouldn't think so, but with every step you take, your legs and torso are working to keep your balance, your head and neck muscles are working to keep those bits upright, and your eyes, as well as the rest of your body, are conveying information about where your body is in space to your brain, which keeps you oriented and controls all the other parts to keep you walking in a straight line without falling over. With all these parts coming together, it sometimes seems a wonder to me that we can walk at all, let alone do something as complicated as throwing a hammer or discus. But throw we can!
Throwing a hammer or a discus is a very complicated series of maneuvers, and it takes years to learn how to do it well. For a discus, the throwing can be broken down into 11 steps, like so:
With the final result looking like this
Throwing a hammer, on the other hand, has 15 steps, and looks like this:
With the final result more like this:
But I keep looking at them, and they keep looking awfully similar (especially since they both apparently require very hardcore soundtracks). Still, hammer throwers don't get dizzy, and discus throwers do. What gives?
So the authors asked 11 discus throwers and 11 hammer throwers (just over half of the discus throwers ALSO threw the hammer and half the hammer throwers ALSO threw the discuss…multi-talented), if they got dizzy. It turns out that about half got dizzy while throwing the discus, but NONE ever got dizzy throwing the hammer. Pretty striking difference.
The scientists then analyzed the VIDEOS of everyone throwing the discus and the hammer, breaking down the movements and steps to see what was involved and try to figure out why this might be the case.
And what they got was a difference in something I immediately identified as spotting.
If any of you out there have ever been trained in dance (ballet, jazz, anything with turns), you'll know what spotting is. When you see those dancers whirling around the stage and somehow never falling over, what they are doing is spotting. When you turn, your body whips around in one continuous motion, and if your head went with it, you'd get dizzy very quickly. In order to prevent this, dancers spot, fixing their eyes on a single point across the room and moving their head FASTER than the rest of them.
The net result of this is that the head moves in fits and starts, jerking around quickly once while the body turns slower. Since you're fixing your eyes on a single point over and over and over again, you are able to fool your brain into thinking you're moving in straight line rather than in a bunch of tight circles, and it thus takes a lot longer for a dancer to become dizzy while turning than you might expect.
And it turns out that the same is true for hammer throwers. Hammer throwers fix their gaze on a single point during a bunch of the steps in their throwing routine as they turn, preventing them from becoming dizzy. In contrast, discus throwers, though they do fix their gaze, do it in only two of the steps in their routine, and thus "spot" a lot less, makin it more likely that they will become dizzy. Not only that, discus throwers have to JUMP, while hammer throwers do not, and that jump may upset the vestibular system even more.
So if we want to stop discus throwers from getting dizzy, we need to try and get them to fix their gaze on a single target more than they already do. Dizzy discus dudes don't focus!