I was just reading Saito Sensei's commments at the beginning of Takemusu Aikido Vol. 1 and he discusses this, so you may wish to refer to this volume for futher insight.
Static techniques imply that your uke is, within reasonable limitation, trying to prevent your motion through the technique being practiced. He/she is not moving toward or away from you but rather standing still. The goal as nage is to initiate motion by sensing the weakness in your uke's balance, or the direction of their will/energy, and to extend you ki so that you can move through the technique successfully.
This is different than ki no nagare, which are more full motion techniques.
At Shin Budo Kai, both are taught as part of the curriculum.