Hey, im really inflexible which sucks for my kicks, as im basically unable to do any except maybe a spinning back to the chest haha. If there are any specific exercises for developing the flexibility for kicks it would be great to know them.
I may be wrong in this assumption but it sounds like that you do very little focused strething, if this is true then you should do a wide range of leg strecthes 2 -3 times a day, you should also make sure that you hold the strecth for a sufficient amount of time. If you keep up stretching often you should soon notice the difference in your kicks
with stretching, don't forget to stretch your quads. when adding mobility to the hip (or any joint really) you need to make sure to develop the flexibility of that joint through all ranges of motion.
many stretch only thier hamstrings and groin believing this is enough. it is not. quads, abs, back... all of these are included in kicking. you need to develop them all.
there are several good books that will illustrate the basics of stretching for strikers/kickboxers.
good book. lots of stretching excercises. even variation programs that are sport specific. stretching for kickboxers, grapplers, basketballers, footballers, etc.
Everytime you do a kick, go as high and as far as you can, that should naturally make it better to, also your kicks may just not be your strong point, maybe you have to best elbows in the world =)
If you are simulating a kick, go as far and as high as you can. If you are kicking with force or at speed, going as far and as high as you can can be dangerous and can cause injury. Be careful how you do this.
I picked up the book Ultimate Flexibility by Sang H. Kim. as suggested by another poster. Very helpful book and not expensive of amazon.