Click on the post tityle to go to a very informative article series by Thomas Kurz
1)Misconceptions on Stretching and Flexibility and the Method of Testing Your Potential to Do a Side Split
2)Difficulties with Doing a Side Split
3)The Method of Testing Your Potential to Do a Front Split
4)Kinds of Flexibility and the Right Role of Splits in Taekwondo, Karate, and Kickboxing
5)Right Stretches for High Kicks with No Warm-Up