Grab and disabledefmovement

[ToNy_W]

well i was just trying to make a npc that disables the player's movements when he grabs it but i got a problem, i figured out that when a player grabs something and is still pressing "a" when the movements get disabled, the player won't be able to move when the movements are enabled again, it will be like the player was still grabbing a wall, if you press the key to walk behinds it will begin to pull, though you're not pushing any keys...So is there a way i can fix the problem?