A trapped grip was a special lightsaber modification. It was essentially a hidden booby trap integrated into the lightsaber's handle that would harm any unauthorized person who tried to activate it. The trap was disarmed by the lightsaber's wielder by a simple action, such as pressing down on a hidden sensor or twisting a knob. Otherwise, an energy discharge would damage the person for as long as they held the lightsaber without disarming the trap.
- Jedi Academy Training Manual