![]() The genetics data from 23andMe provides some support for both. “I’m a little dubious,” Hain says, but “it doesn’t sound tremendously different.” Both involve a dissonance between expectations and reality, between what the body is used to and what it’s experiencing. Stoffregen says these two ways of conceptualizing motion sickness are “just not on the same planet,” but they seem somewhat compatible to me. You’ll no longer have the relationship between postural movement and postural outcome.” That instability, by this logic, is what leads to feeling ill. “You need to press with your toes, but what if you do that just as the ship is rolling out from under you? That means that the movement you spent your whole life using to successfully stabilize yourself, your body will move in ways you don’t want it to move. “Let’s say you're standing and your body goes forward,” Stoffregen says. Put those people on a ship, though, and tried-and-true methods of balance often fail. Both theories of motion sickness involve a dissonance between expectations and reality. ![]() That’s what people do all the time, just on a smaller scale. Sometimes in yoga classes, teachers will tell you to lean forward onto your toes, then back onto your heels, then return to the center, to get your balance. It’s not enough to be noticeable-an inch or two in each direction, a little at a time. This activity results in a little bit of movement, called body sway. “If you relax all your muscles, you collapse on the floor,” Stoffregen says. Even to stand still, muscles have to be active. Understanding postural stability theory starts with knowing that the human body is never totally motionless. “We need to look at the actual physical motions.” “Never mind the contents of the mind,” he says. Tom Stoffregen, a professor of kinesiology at the University of Minnesota, has a different explanation. MOTION SICKNESS GLASSES REVIEWS FREEYour eyes are telling you you’re in free flight, but the seat of your pants is saying you’re not going anywhere,” says Timothy Hain, an otoneurologist and professor emeritus at Northwestern University, describing another mismatch scenario in which people get motion sick-while looking at screens. MOTION SICKNESS GLASSES REVIEWS MOVIE“Another place might be, you’re sitting in a movie theater, and you see a plane going over a cliff. And if someone’s eyes tell him one thing-“I am sitting still in a car,” for instance-and his ears tell him another-“I’m careening down the Autobahn at 100 miles an hour”-that mismatch can cause a problem. The inner ear is the seat of the vestibular system, which deals with movement and balance. To keep our balance while navigating the world, humans use their eyes, ears, feet, maybe hands if they’re babies who can crawl. The prevailing theory of what causes the dizziness, headaches, and nausea of motion sickness is that riding in vehicles, or on camels, causes confusion between some of the senses. (And, apparently, camels?) If someone's eyes tell him one thing and his ears tell him another, that mismatch can cause a problem. ![]() While anybody can get motion sick, with sufficient motion, there’s still much left unknown about why some people are more likely to get sick on boats-and cars, and planes, and carnival rides, and tire swings. A recent study by genetics company 23andMe, published in Human Molecular Genetics, sheds some light on genetic factors associated with motion-sickness, supporting some existing theories about what parts of the body are involved in the phenomenon. Why people get motion-sick is a mystery, and how motion-sickness works is less of a mystery, but more of a debate. “If it was not for sea-sickness, the whole world would be sailors.” Even farther back, Greek physician Hippocrates presaged our current term, “motion sickness,” writing, “sailing on the sea proves that motion disorders the body.” “The misery I endured from sea-sickness is far far beyond what I ever guessed at,” Charles Darwin once wrote to his father. ![]() For so long as man has attempted to tame and traverse the sea, the sea has punished him for it. Humans have explored a mere five percent of the oceans over the long and storied history of seafaring, and even this knowledge has come at a cost. The wide expanse of blue water that covers most of this world holds many mysteries. ![]()
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