If you put a flat-blade screw driver between the axle plate and the arm on the torque side (in this photo I'm about to loosen the axle nut and compress the axle plate into the screw driver resting on the swing-arm) then the screw driver will help hold the axle plate in its' position and will have a reduced chance of bending the axle plate and gouging up the swing-arm.
Just thought I'd share...