Yin-yang is a concept based on the theory of taichi and the five elements. The most important factor about yin-yang focuses on the inter-relationship between the forces of being and non-being. Just like the concept of taichi and wuchi (the opposite of taichi); male and female; positive and negative; lightness and darkness; happiness and sadness, and so on, the major concept of yin and yang consists of a force and counterforce which reciprocally interact with each other to achieve perfect harmony. Therefore, the theory of yin and yang strictly is not talking about things being black or white, right or wrong, or good or bad.
The theory of chikung works together with the law of nature,yin and yang. Breathing, for example, appears like the tao of yin and yang. Inhaling and exhaling and the stretching exercise which accompanies them focus on the connection between our internal organs and our limbs. In other words, breathing includes the internal movement within our body as well as the external movement of our limbs and the levels of our mind and spirit at the same time. So, if we think of our mind and spirit as yin and the movement and circulation within our body and internal organs as yang, then we will understand how the theory of yin-yang works within our body and mind.
Chi Kung Culture Society of TAIPEI