How to look at long term kick training

I have been trying to re work my body back in decent shape. That says yes I am out of shape and but there is a piece of what I do that stays with me even when I am fat. Firstly external training of flexibility comes and goes. This is stretching your legs just before a class and you open up to kick high then months go and you can not kick above your waist. Then there is the deeper training where you re-form your muscles to be able to not kick for a year and still have some real height.

The hamstring is a cluster of muscles that brace the leg and work against the front of the leg. Wikipedia even goes to say " In walking, they (the hamstring tendons) are most important as an antagonist to the quadriceps in the deceleration of knee extension." This cluster is usually the main focus of being able to kick high as it is the place that will impede your height more than anything other than a large belly. 

The thing that is always easy to determine is that you feel the stretch behind the knee or in the back of the thigh. The less focused part of the muscle is what is going on in the hip. In Chinese KungFu (more specifically Shaolin and Wushu ) there is enough use of the hip in circular based kicking that many of the hip muscles get stronger(and flexible) by use. There are also a lot of focus on single direction stretching that only works behind the knee and if care is not taken hip injures will occur. I have seen this with other styles as well but have more experience in the straight leg kicking. 

One thing that I believe points to a really interesting conclusion and it is called the Lombard Paradox. This basically says that both the front and back of the leg work together even when they basically built to fight each other. This has been studied in cycling and is often used for runners with doing downhill running to over train the hamstring. Where this intersects with Kicking is that by training the hamstring the quad is trained as well.

One thing my Shaolin instructor worked on was once you were above your head with a kick (regarding flexibility), he would then have us slowly raise leg high then bring it down fast as possible. I have taken this principals to getting 100 of these kind of kicks before you try and really work on speed with kicking up. I found this to be useful to be cause I had enough stability that I never ran into problems where I had problems before.

Another point is to activate hips during stretching. This will allow the leg to open up fully and not over emphasize on hyper extension of the knee. I came to this after my time in China where the only way to work your legs was through hypertension of the hamstring. Yes it worked but it really threw the balance of my legs off. I would over extend in stances and never feel firm. It has taken almost 10 years of really working on re- alignment of my legs to fix what I did. I