I did a lot of swaying the hips and tail bone to engage the muscles between the hip bones.  Walking through the rest of the day I had a sense of my upper body, especially the space between my pelvis and chest LIFTING OUT OF MY PELVIS.  I realised that at other times I might be sinking into the pelvis.  Activating the sensation of Stability helped my spine to 'float' up and had a positive effect on my posture.  'Aha!'