ˇ§Ding is on interstice and Zhong should have horizontalˇ¨ that means the shen fai (the way of your body moving). Zhong Ding is very important. No matter defence or offence you must do zhong ding well. First of all, you must identi! Xu and Shi. This can not be simply understood by putting weight on one leg that is Shi and reverse is Shi only. You should know there is Shi in the Xu and Xu in the Shi. It seems difficult to understand. Where is the Xu in the Shi? An example can be that when our hip bone with your body sitting on you leg is Shi. However, there is a membrane between them. Therefore, no matter how much pressure it has, there is always a space to move. This is called ˇ§having intersticeˇ¨ in martial art term. On the same time, your two hip bones should stretch horizontally. It says ˇ§hip bone open and crotch round.ˇ¨ You will have the feeling of.stability. In arrow and bow step your front leg also should have this feel. Hip bone shong and sink and crotch has the mind of open. Thus you have the feeling of Zhong Ding. When you doing the taiji form, you should also find this feeling. Itˇ¦s easy to have the problem of ˇ§leaning.ˇ¨ This problem is to put your weight center to the knee joint and hip bone joint. It seems easy for you to bend. However, it may cause problem for your joints. The correct way is that hip bone moves backwards and let your weight be supported by your leg muscle. That is going to decrease the burden of your knee joint and your leg feel stable. Although your leg muscle feels sore, you will feel it is very comfortable and you get the kongfu..
ˇ§Zi is on double weight and Tong is on single light.ˇ¨ This two sentences tell you the method of jin. ˇ§Ziˇ¨ means not active and reverse is Tong. Zi cannot be only understood as the equal distribution of your weight on the two legs. Like wave hands like cloud and cross hands all have the time that your weight is equally distributed on the legs. It is not double weight. The way of double weight is the appearance of your ˇ§shen fai.ˇ¨ That is your transition between forward and backward is not clear. In this case your move looks dull. Like ˇ§brush knee and pushˇ¨ you should let your hip bone joint brings your body move forward uprightly. Then the heel of your back leg lifts. When you feel your weight center (e.g. left) is stable then your right leg up and forward. Thus, you feel very active and not Zi. If your forward is leading by the leaning of your body, your hip will protrude and back will be stiff, and it will produce several force points. The second problem of double weight is the problem in the execution of the jin. This is another topic.
ˇ§Xu is on offensive and s&i is on defensive.ˇ¨ It is talking the way ofjin. It should be understood from the change of Ying and Yang. There is a quite simple example for this. The existence of strength is on pair. Only on the pair the strength will have the effort. If your strength does not perform on others that is practicing your form. In this case, you can feel whatever you want. However, if you practice with others, it is not the same story. You should think how you perform your strength to others and also you should feel how otherˇ¦s strength work on your body. The existence of the pair of strength and the change of this strength both in direction and quantity reflects the relation of ˇ§Xu and Shi.ˇ¨ For instance, in the push hands xu and shi is produce on the first touch of the hands. If your opponent push in that is ˇ§Shi and your ward off and ˇ§Lu backˇ¨ is the ˇ§Xu.ˇ¨ If your opponent cannot feel the point (Shi), he/she has no way to push. If he/she can feel that point, itˇ¦s easy for himlher to control you. That means you are not able to control Xu and shi well. The high level taiji person should be able to change xu and shi depending on the change of your opponent. In the practice of your form, we should follow the rule exactly, while using it we should not stick on it. We should change combine the postures of the form any time when we need them. That is the way of high level martial artists normally do ˇ§obey the rule while not stick on the rule.ˇ¨
As the whole, after learning the form we should try to understand that based on the eighteen elements. ˇ§Pong, Lu, Ji, An, Cai, Li, Zou and Kaoˇ¨ are the fundamental techniques. Forward, backward left and right watch are both technique and eye methods. ˇ§Zhong Dingˇ¨ is shen fai and ˇ§Zi and Tongˇ¨ is Jin fai. ˇ§Xu and shi: is the soul and spirit. Try to understand and combine all of those. Feel the details when you practice, my friends, you will not only have the fun but also the longevity.