Though many science textbooks claim otherwise, humans boast relatively short strides.

Humans were able to shorten their stride by abandoning the swiveling hips deployed by their primate relatives, according to a study published Friday in the Journal of Experimental Biology.

Until recently, scientists assumed humans had done just the opposite, lengthening their stride for efficiency.

"This is taught in almost every introductory class and textbook," lead study author Nathan Thompson, a researcher at the New York Institute of Technology, said in a press release.

While studying the gait of our closest living relatives, chimpanzees, Thompson surmised that pelvis rotation allowed chimps to lengthen their stride.

When Thompson and his research partners compared the strides of humans and chimps, scientists found the strides of chimps relative to height are 25% longer.

To analyze the strides of humans and chimpanzees, researchers filmed the two species walking and conducted a 3D analysis of their biomechanics. Scientists determined the legs of humans were 112% longer than the legs of chimps, but their strides were only 26.7% longer.

Researchers found humans barely rotate their hips as they walk, while chimpanzees swivel their hips between 28 and 61 degrees. According to the analysis, chimpanzees use their swiveling hips to extend their strides 5.4 times more, relative to height, than the slight rotation of human hips.

"I think that chimpanzees use pelvic rotations to try to squeeze every bit of stride length out, otherwise their strides would be — absolutely — very small," Thompson said. "I don't think there are a lot of options other than rotating the pelvis, given their anatomical constraints."

Though researchers can't yet be certain why humans abandoned a pronounced swivel, Thompson suspects excess rotation would throw off the rhythm of the human walk, interrupting the timing of our swinging arms and forcing our muscles to work harder.

From an energy efficiency perspective, a longer stride may not be ideal.

"Humans have had about 7 million years of selective pressure for economical bipedalism," Thompson said.

"This means that there has been a lot of time to experiment with the costs and benefits, so it might be worth it to walk with slightly shorter strides, because whatever energy we lose, we might make up elsewhere."