A dear friend has been diagnosed with blood cancer and has excruciating pain in his knee. The doctor has given him cocodamol, but he is still in a lot of pain. They said that they cannot give him a steroid injection because he might get an infection that will interfere with his chemo. He is now using a walking stick, a knee brace and ibuprofen gel, but to no avail. Has anyone had experience of TENS as a pain relief?