“The body must be stable for the mind to be stable. It has been said ‘An anxious mind cannot exist in a relaxed body.’ The mind and body are clearly connected, and when the body and breath be- come peaceful, the mind easily follows.
“If your posture is firm and balanced, it will be easy for you to relax and you will already be halfway toward achieving a tranquil and focused mind. Conversely, if your posture lacks balance and stability, your muscles will soon tire and become tense. You will find it difficult to relax, and your attention will waver like a candle in the wind.”
-From Awaken Healing Light of the Tao, by Mantak Chia