Very Important Methods of Relaxing the Waist
In Yang-style Tai Chi, relaxing the waist is emphasized as a crucial point: "The waist is the master of the whole body. Only when the waist is relaxed, then the feet are powerful, and the lower stance is stable. Changes between solidity and emptiness all come from the turning of the waist, thus it's said that the source of command is in the space of the waist. Any lack of strength must be sought in the waist and legs."