I am sitting here with my new Tens machine doing it's stuff on my back, I bought it for only £15 in Lloyds chemist on Saturday but only plucked up the courage to try it just now as the pain in my back was getting bad. When it has finished on my lower back I may shift it to my neck, I might not need to take the painkillers if it works! Update: I read the instructions while it was working, and you can't use it again for two hours and have to be careful where you put the pads, so I haven't done the upper back yet - neck is out of the question!
At the moment it is doing a 15 minute programme where it varies what it is doing, and I am enjoying the way it feels at the moment! Must make a note to buy them for my parents for Christmas - Dad anyway for his back, he hasn't got any pacemakers or implants so it should be fine.