Hey O'unpronouncable one. Long time. Hope you are enjoying the Canadian winter. That's one of the things I do not miss.
We call this effect Ido Ryoku - the power of movement. To generate it nothing must be done in isolation and when done right it is unstopable. The ability to use this effect has been described to me as the difference between a good teacher of Aikido and an Aikido master.
Strangely enough while I was talking to someone in the know about this I was told that some people (in other styles) mean Ido Ryoku when they talk about Ki. He quickly added that most people who talk about Ki don't understand Ido Ryoku. Take those statements as you will.