Imagine someone running. Now freeze him in place. How is he positioned? Now stand up and reproduce with your body the pose you've pictured in your mind. It doesn't have to be perfect, just capture the essence. Are you doing it? Good. Now where are your arms and legs? Are they where they should be?

You might be surprised to learn how many people get this wrong – "wrong," here, referring to the incorrect placement of one's arms relative to one's legs, when miming a runner mid-stride. It turns out humans are stunningly bad at this. In fact, a recent study by psychologist Julian Meltzoff reveals we're bad at depicting a runner's form not just with our bodies, but in our art, as well:

Paintings, drawings, and sculptures from ancient art to the present reveal a curious error in the portrayal of human gait. In natural human gait the arm and leg on 1 side of the body swing in opposite directions to each other—contralaterally. The error is to depict the arm and leg on the same side of the body as if swinging in the same direction—homolaterally.

We've been doing this for millennia. At The Atlantic, Rose Eveleth dug up a sculptural example from 660 B.C. Egypt and a vase from 530 B.C. Greece (the latter is pictured at the top of this post). Guides to figure drawing commit the error, too, whether it's Peter Paul Rubens's 18th Century anatomical drawing guide, Théorie de la Figure Humaine or a step-by-step tutorial at Even Leonardo DaVinci, a stickler for anatomical correctness, screwed this up.


In fact, not only are we bad at depicting running, we're also pretty terrible at identifying incorrect running form. Here's Eveleth with the numbers (emphasis added):

Meltzoff's study also looked into just how good people were at identifying correct and incorrect running posture. When participants were presented with a person walking, and asked to label which legs and arms were the right and the left, only 17 percent of them got it right. The other 83 percent marked the forward arm and leg as both being on the same side. In fact, they would have done just as well to guess randomly. And when participants were asked to pose in mid-run, only 14 percent of them picked the pose that actually reflected running. The other 86 percent froze with the same sided arm and leg moving forward.

Why we're so bad at this is unclear, but some psychologists think it could have something to do with our sense of proprioception – how one perceives her body, and the positioning of its various parts, in space. You can read what one such psychologist has to say on the hypothesized role of proprioception (and a bunch of pictures of people walking and running funny) in Eveleth's post at The Atlantic.

Top image via Wikimedia Commons