Wilson Kipsang (IMAGE) Forschungszentrum Juelich Caption Thanks to biological lubrication natural joints move almost frictionless and withstand enormous loads. Credit Tom Page (<a target="_blank" href="https://www.flickr.com/photos/tompagenet/6957645328">https://www.flickr.com/photos/tompagenet/6957645328</a>, <a target="_blank" href="https://creativecommons.org/licenses/by-sa/2.0/deed.en">https://creativecommons.org/licenses/by-sa/2.0/deed.en</a>) Usage Restrictions CC BY-SA 2.0, <a target="_blank" href="https://creativecommons.org/licenses/by-sa/2.0/deed.en">https://creativecommons.org/licenses/by-sa/2.0/deed.en</a> License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.