with all three current systems depending on the placement of the leads (cervicle-arms,lumbarr-legs), your rep should be able to adjust your settings so that the coverage moves from the furthest point (fingers/toes) to the closest point (shoulder/pelvis/lowback) can be covered without further surgery. you just need to contact your rep and they can set up an appointment to work on it.
there is however some distinction for a shift from one side to the other and coverage capacity. some doctors lay out leads on both sides which means if your symptoms jump the stim can be adjusted. conversely, some doctors especially those who were working under a set ins budget or as a result of symptoms displayed in only one area will only lay out one side of leads.
so if you have a stim unit (that isnt shocking you...i would be yanking mine too) that isnt functioning as intended you really need to talk to your doc and your rep. if your rep sees you and says nothing is wrong and you still feel like something is wrong with the unit (that isnt life threatening) ask for the reps supervisor to get involved and ask for the unit area tech guys to be involved. at least with abs (not sure about the other 2) if they insert your unit and your unit fails they will deal with it...they are replacing mine.
the cervicle ones, particularly earlier versions, take a very long time to get tuned in so they work well.
there seems to be some confusion