I wonder if anyone can help me?
I just got a TENS unit. It has two channels that can be independently set.
I have a L5 S1 herniation with sciatica pains down my RH leg. Quite a lot of numbness in the RH side of my foot too.
The diagram that came with the machine isn't very precise. So I have had one set of pads either side of my spine around the L4 type height; and the other two at the top and bottom of my thigh.
But I have seen other diagrams where the pads are arranged in a much more criss-cross system with +ve on one side of the lower spine and the related -ve terminal at the bottom of the thigh etc.
I'm not sure whether it does a lot of good - but it seems pretty pleasant!