First photo: Run in place and check the natural distance of the feet. Then stand on your toes and ease your heels down on the ground. This is the relaxed standing posture.
Second photo: Person who does Ki test stands diagonally in front and left of her partner and with her right hand, pushes gently on examinee's body between the left chest and shoulder.
Third photo: Examinee can keep her posture stable without trying to not move.
I will explain some important points with Ki Testing. It is not important if you move or not move. When you receive Ki test, you can resist "not to move" intentionally. However, if you think "do not move", you become tense and as a result, you loose natural stability. There is no value in trying to not move. The posture which is in harmony with the Universe or the posture with oneness of mind and body has natural stability. If your posture is correct, your posture is naturally stable. You do not have to brace yourself. The posture with oneness of mind and body is not only stable but allows you to move at anytime. If your body is tense, you cannot move freely at any time. If you tense your muscles in your legs or lower abdomen, you cannot be stable and cannot move freely. The posture in harmony with the Universe is the posture with oneness of mind and body. In this posture natural stability is kept and you can move anytime quickly. Let's do Ki test while sitting (Seiza).
First, rise on your knees as shown in the photo. Many people have a habit of putting their chest out and becoming tense. Move your shoulders up and down. You must move only your shoulder. You will find that it is difficult to move your shoulders up and down when you are tense.
On the other hand, if you have a hunched posture, it is difficult to move your shoulders up and down. The position that allows you to move your shoulders up and down the easiest is the natural position of the shoulder.
Next, sit down calmly. When you sit down, please do not push down on your lower body. When you sit, cross your big toes, one over the other. It does not matter which toe is above.
Check to be sure that you move your shoulders up and down several times. Put your hand on your lap lightly. Do not push down. When you receive Ki test, you will find that you are stable naturally without trying to not move. This is Seiza (sitting) posture with oneness of mind and body.