X-Ray Video of Double Kneecap (VIDEO) Society for Experimental Biology This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption An X-ray video shows the movement of the double-kneecap inside an ostrich leg. Credit Ms Sophie Regnault Usage Restrictions Video only to be used with credit. 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.