In Tai Chi Nei Gung the 3 Dan Tiens Linear practice must first be performed with specific attention given to the external and internal physical alignment as well as the proper energetic alignment of the 3 Dan Tiens. Eventually, over time, you can move while only having to focus on the alignment of the 3 Dan Tiens. Last, but not least, you can move with the proper feeling of the 3 Dan Tiens linear and not have to worry about the rest.
When you perform 3 Dan Tiens linear correctly it will enhance all of the other internal aspects of your Tai Chi including the other Tai Chi Nei Gung skills. 3 Dan Tiens Linear is explained in quite a bit of detail in my book Tai Chi Energy: Activation, Cultivation and Flow.
On the Mark!! This is the Key to Tai-Chi’s Phenomenal Power