[BLENDER] change edit mode pose

Hi , so i have seen alot of answers to do with blender on here so i decided that i should ask here , because alot of people know useful things on this site :) , so anyway , i have a hand rig and it works fine animated and all , but when i click on the hand and go into edit mode the position of the arm changes back to the position i made it in , i have 2 armatures in my scene already if that helps :) Thank you very much for your help