Sorry I didn't see this sooner. My particular TENS Unit has icons for different positions, and I select the one for the lower back. It is set to pulse, although I don't know if that matters as far as effectiveness. I try to dial it up to 55, and keep it on about 20-30 minutes before bedtime. As far as electrode placement, I place them in a square on the very lower back (more accurately, buttocks), about 3 inches to either side of midline. I use one lead wire to connect to both electrodes on the right, and the other for both electrodes on the left. I have found that low batteries or electrodes that aren't sticky enough cause the treatment to sting and be less effective. I've heard there's a product that extends the use of an electrode. I get 3 uses out of them, usually dampen the sticky side of them before storing after the 2nd use and it gets me one more use. Ideally one would have a physical therapist who could instruct them in proper use of the TENS. I do what I do based on trial and error, and believe me, that trial period was absolutely miserable! I have rare occasions these days that I have to get back out of bed and use it again to really rest, but most nights it is quite effective. It saved my sanity on a recent train trip and settled my legs down enough to let me sit still.