I found a (new?) way to prevent your foot pedal from moving across the floor. Place a furniture mover slider upside down so that the foam side is on the floor or carpet. I used double sided sticky tape to attatch the pedal to the smooth side. It is the best thing I have found to keep my foot pedal in place. I used the large size (7"x7"). I got them at Harbor Tool.under $5.
foot pedal on sliders
furniture mover sliders