Waist turns, hips do not! Most who do this are surprised when they are told how much their hips are moving...unless trained one simply does not feel such extraneous movement.Doing the Lions share of repairing the hole where logical reasoning disappeared, "righting the ship" and saving Tai Chi.

from Instagram

Junction of movement has to be in torso to be "internal"

Starting at 1:15 you hear Master Hwa address "hips vs. waist" and ask "...some of you were here last time, I want to see...turning movement, how do you turn...". The fellow behind (who I recall from the previous year at this same workshop) turns at the hips and turning his whole body.  You know it is very interesting that 

Did you know that the ability to turn from the waist, not turning the hips is considered the “second stage” of learning in Tai Chi. Did you know that if you don’t reach this stage you are not truly practicing Tai Chi? Did you know that THE TAO OF TAI-CHI CHUAN: Way to Rejuvenation" Jou Tsung Hwa,  Tai Chi Foundation, 1991, page A31, stated that "The Second Stage. The hallmark of the second stage is the use of torso method. Torso method is characterized by use of the body, specifically the waist and spine, to initiate and empower the movements of the arms and legs . Only those who reach this stage can truly be said to be practicing Tai Chi, yet these are few indeed."  Master Hwa once told me that he would have liked to meet Master Jou “…he was someone that really was searching for the truth about Tai Chi…”