Ways to Stretch With a Hyperextended Knee. Part of the series: Yoga & Stretching Tips. Hyper-extended knees have excessive motion in the joint and it can actually be dangerous and cause injury. Find out about ways to stretch with a hyper-extended knee with help from an experienced yoga professional in this free video clip. Read more: www.livestrong.com/video/1008408-ways-stretch-hype…