No worries Ali about posting it here , where it may be useful dont hesitate, I just thought since I was responding to the same post I would say where the info had come from (I was about to repost it myself till I realised what it was lol).

Also, a good way to try and use it for two limbs (two lower limbs for example) is place both electrodes, one either side of your spinal column. This way they are intercepting the pain signals before they enter your spinal cord from both limbs. Make sure you place them on your lower back, or even try placing them just above where you sit on the back of your hips (kinda your bottom). But having a machine that can take several pairs of electrodes is also helpful.


As far as the centrally maintained pain (this is my understanding of how the TENS works in this situation) TENS relys on the gating theory so it targets the faster conducting nerve fibres whereas pain signals travel along the slower fibres, but in centrally maintained pain (same as independent pain, pain in the CNS) the body is still translating pain signals are coming from the periphery even though there are none coming. So, if you use a TENS, all of a sudden there are these signals coming from that limb that are NOT pain signals and they are the faster nerves too so the brain starts to deal with those signals that are really coming and it doesnt have time to continue the pain ones is has created in itself, the gating theory still applies. This is why it is still ok to try using the TENS in chronic pain situations as almost everyone with chronic pain will have these central changes in the brain.
This is actually pretty hard to understand and a lot of medical people dont really get it either as they haven't studied the relevant pain science.

Hope this was helpful