The most thought any of us give to our kneecaps is whether or not our shorts are too far above or too far below them. Sometimes we are reminded they are there when we trip and they get scraped up, but for the most part they are a neglected part of our body. It’s too bad though, because kneecaps make a huge difference in our ability to bend our legs, and if you think that’s overstating it just grab yourself some chopsticks and see for yourself.

That’s exactly what Sophie Regnault, a PhD student studying kneecap evolution and biomechanics, did, and the results are clear: kneecaps help us move way more than we realize. “I had a meeting with my PhD supervisors, and was trying to figure out some of the mechanical arguments for why having a kneecap is a good thing,” she told Nerdist, “My fiancé and I had just had some Chinese takeout so I made a quick model to get my head around it.”

With just the chopsticks, a little ball, and a rubber band to replicate the tendon, it’s clear how much range of motion we gain as a result of that little kneecap. The results surprised Regnault herself. “I was expecting a really minor mechanical advantage.” Instead we see a greater range of motion with a lot more ease.

Turns out kneecaps aren’t just ignored by the populace, they’ve been generally ignored by scientists too. “I always start off introducing my research saying that no-one really cares about kneecaps and other sesamoid bones because there is (relatively) little research on how they’ve evolved and how they affect the mechanics of movement,” says Regnault.

Her simple demonstration hit a nerve though, with people suddenly taking a great interest in how and why we evolved such a great little mechanism on our knees, but not in other places. “That was the best thing for me: reading the Reddit comments with people asking how that would have evolved, or why we don’t have elbowcaps, or what happens if you have two kneecaps, and realizing that people are actually interested in the questions I am trying to answer!” You can read through that front-page Reddit discussion here.

Also, that might be the most productive Chinese food dinner since they figured out where Sollozzo was bringing Michael Corleone for the meeting. Except instead of ending in a double murder we got a really cool display for an under appreciated part of our anatomy.

What aspects of our evolutionary process does this kneecap demonstration make you wonder about? Tell us below.