To many of us stretching is that bit we do after training to get rid of gathered lactic acid and to relax the muscles. These stretches, however, are not that kind of stretch at all. They are meant to enable you to kick high and also to develop kicking power.
The effectiveness of the exercise lie therein that one is isometrically stretching the muscles on one side of the body while the other side is being exercised isometrically.
The stretches take on the form of three basic kicks, the front-, side- and back kick.
These kicks all have one thing in common- they drive into the target.
To do each stretch you have to stand far enough from a wall so that you have to overextend to reach it with your foot. The more flexible you are-the further away you may stand.
Then the foot is placed against the wall. This is where you push against the wall as hard as you can, holding the position of any of these kicks as shown in the sketch.
20 seconds on each position, with each leg, should be enough. Then go forth and kick!