I didn't see you standing on that pile. The details are not clear. However, there is definitely something wrong with the pain. There may be several reasons for this problem: first, it may be that the coccyx itself is diseased and now it has an attack. I suggest you see a doctor. If it is delayed for a long time, it will be troublesome and cannot be neglected; Second, the posture may be wrong, or too stiff, or too loose and soft. If you stand right, you should feel straight. There is. If not, you can't force it. Third, the idea is too heavy and too hard, and the pile should be relaxed and conform to the norms, with some looseness. I wonder how long you've been practicing. If you are just starting to learn, even if there is pain, it should be muscle pain, not bone headache. Fourth, it may be when you are injured. Sometimes you may not feel it at that time, but after a while you will react and the blood will not flow there. The so-called general rule does not hurt, and pain will not work. The right medicine can cure the disease. Let's see what the reason is first.