Sine wave is a polarizing topic in Taekwon-do. One side believes in it zealously, while the other shuns the practice set forth by General Choi in the 80s. My school doesn't execute forms with sine wave, as our Malaysian heritage somehow skipped the sea change that divided TKD practitioners forever. Regardless of our C-step execution, we should all be practicing a sine wave when we execute our forms, not necessarily the down up down stance kind of sine wave, (although many do, and I don't judge). I'm referring to the relaxed, tensed, relaxed state as we go from transition to transition -- movement to movement.
I've been hung up on this since learning Tong-Il a few weeks ago and now more than ever I feel a pull towards mastering this concept which is easy to conceptualize, but very difficult to execute, let alone master. To date I have focused my Tuesday night class on this topic in a variety of ways for more than a few weeks in a row now. It's eating at me for a few reasons. For one thing, the tension / relaxation (from here on referred to as the TR sine) in forms, when executed properly looks amazing. Turn on any of those WKF world championship videos that everyone raves about on the forums and you'll see people who have mastered the art of the TR sine. Their forms look so fast, so fluid and so clean because they are experts at, among other things, starting their movement from a completely relaxed state, going to complete tension at the point of the strike or block and returning, nearly instantly to that relaxed state. I'd argue that it is the contrast of the tension and calm that is so compelling about these executions of form. This is especially evident whenever a forms practitioner executes a move in a form that is fast, transitions to something that is done slow and smooth and then immediately executes a fast move right after. It grabs the eye, and is often a thing of beauty.
It's not just for looks though. Learning to harness the TR sine, and executing it is a very effective way to increase hand and foot speed through forms practice. When performed properly, your entire form becomes one giant plyometric exorcise! All the people who believe that forms do not help your fighting are clearly blind to the fact that forms are a great place to develop actual speed. Forms have most definitely helped increase my explosiveness in sparring and I attribute that to constantly focusing on the TR sine. Although I don't get the opportunity to spar as much as I like, people still consider me "fast". Many factors go into being a "fast" fighter but my actual speed has been maintained thanks to TR sine. Because of this I'll never be one of those people that sees forms as pointless. Forms are the antithesis of pointless, if you are practicing them correctly that is.
I find that true relaxation is the hardest part for most people to accomplish in pursuit of a true TR sine. Tensing the muscles and producing power is easy for most people, but when I look at them doing a series moves and say "relax" to them, I frequently get blank stares and a continuation of a plateau of tension and power. They just never come down after adding power to their first strike. It is hard though, when we occupy our mind with the fear of looking weak, the fear of making a mistake, the fear of criticism from the higher ranking students, the fear created by "oh no the teacher is watching me" it can be very hard to relax. I find the average student is dealing with one or two of these fears at any given time during every classroom session. They are natural states of mind that even seasoned veterans like me succumb to from time to time -- it is no wonder relaxing can be challenging to achieve.
Thus the quest for absolute relaxation starts with the state of mind. I used to tell my students to practice their forms as if they are the only thing that exists in the entire universe, but ultimately the cliche, "dance like no one is watching" is probably more accessible and easier to visualize. As a person who never danced that well, I was incapable of this and had to actually start this in my solo training. I actually needed proof that no one was watching, it seemed, to execute forms like no one was watching. In time I was able to quell all of those fears and actually do my forms relaxed in or before regular class.
Relaxation is paramount in self defense situations as well, as being too tense can take its toll on a fighter in a myriad of different ways. By being in relaxed state during self defense, we can limit or prevent tunnel vision and actually be aware of what is going on around us in a potentially very stressful situation. We also limit over extension when relaxed -- and keep our openings after attack at a minimum. By being relaxed we try to force technique less, which also allows us to conserve energy. Relaxation in fighting comes more from experience practicing self defense and sparring, but making it an important part of your forms will only help you in these areas as well.
I attribute much of my forms skills to understanding the TR sine and always making it a focus of my practice now. As I used to just dial up the forms to maximum power and intensity, I find that now I am actually more explosive, my forms look even better, and my endurance is better because I'm actually not working as hard. Concentrate on your relaxation and your forms as well as many other attributes should improve!
