if you’ve ever studied your cat walking, you might not notice anything wrong, but to scientists, the way cat legs work are a mystery.

“You can imagine walking around like this takes a lot of exertion,” says John Hutchinson, one of the researchers studying how cat legs work. “We still don’t really understand how they do that without suffering problems.”

“Their muscles don’t increase enough in size to compensate for how much bigger they are,” says Anjali Goswami, another researcher. “They definitely get weaker as they get bigger, relative to their body size.”

The next time you watch your cat walk, watch carefully. You could be witnessing a miracle that scientists still can’t explain.

To read more about the research into cat legs, click here.