This is something you do not want to do in kendo. When you get struck, usually you are in this status of itsuku.
Itsuku is a verb that expresses the state of your mind and body.
When your mind is in the state of "itsuku", your mind is stuck.
It has lost its flow. It is in the state of "shishin".
Thus, if you are physically in the state of "itsuku", it simply means that you cannot move.
You lose the movement of your body. Probably because your mind is in the state of shishin.
Imagine when you are surprised. Someone just surprised you and your eyes are now wide open and your body gets frozen. Your leges are hard as logs. You simply stop moving.
This is the state of "Itsuku". How do we use it?
The reason why you got struck was because you itsuita.
Of course, the whole sentence should be in Japanese and "itsuita" is a past form of "itsuku".
For your information, "
" means "to sit", "to reside", "to stay", "to save" and so on. You get the picture, right? "
" is to "attach", "to be in a situation that is just explained previously " and so on. In this case, it is the latter. Thus, you put yourself in a situation where you cannot move.