The term here refers to the erectness of postures and reasonableness of mental activity.
The human body is by nature gracefully and symmetrically construct-ed. But it is distorted, to varying degrees, by daily work and other physi-cal activities. Thus, the restoration of this symmetry is an important way of tapping its latent ability and improving health. That is what "going back into void" as described in qigong books really means. Keep physical movements correct and you can make your posture best and achieve the harmony of all body parts -- the left and the right, the upper and the low-er and the inside and the outside, thus laying foundation for further prac-tice.
The reasonableness of mental activity is another requirement for you to fulfill after making your physical movements correct. When you do qigong exercises, keep yourself calm and without any disturbances and losses of qi. And be sure to make yourself free of distracting thoughts and mental burdens in daily life.
As part and parcel of various qigong exercises, zheng can be used to put internal activities in order so as to achieve the harmony of mental activ-ity and physical movements.
