After each technique you should be able to move in any direction. Itsuki is to get stuck to the floor. When your timing is off or your body -center of gravity- is incorrectly positioned then you will suffer itsuki.
How to make your enemy get itsuki? Two reliable methods are feints and physical manipulation.
Physical manipulation is to control and force the opponents weight distribution, by for example pulling his arm in a downward angle, pulling his weight to his front leg making it more difficult to move. 
PRINCIPLES