How to defend yourself against A knife attack
If someone holds a knife to your throat, that is dangerous. And if there is a wall behind you, it puts you in a vulnerable position. You cannot move backward. In this situation, don't make an obvious move that the attacker can easily see. Your first move should be moving the knife away from your throat, then attack instantly. You have to be very fast. Otherwise, the attacker will understand what you are going to do.