Impossible Arm Chopper

A great penetration effect, and easy to do. Display a wooden blade and stocks - everything can be freely shown. The blade is replaced in the stocks and a spectator is asked to place their arm through the opening in the stocks, just below the blades edge. Then quickly, the solid wooden blade is pushed downward, through the spectator's arm! There's a pause, as the impossibility sinks in - then the stock is split open and removed from around the blade. The solid wooden blade is left wrapped around the spectator's arm!