I wonder about your mattress. Time to revisit that?Well you all, 2 nights ago I did the TENS therapy. Over a 3hr period I used it three times at 45min periods. My lower back L5 S1 are bone to bone. For the last 3 months. I have had shooting pains from my back down my leg. It felt like a fireball. When I went to bed around 1am. I slept until 12noon. I haven't had 3hrs straight sleep for years. My back was hurting so I did 45min intervals on and off all day. Went to bed last night around 1am and slept till 9am. Back was hurting again so I used the unit again. I hope I can say that the TENS therapy really works. Time will tell!