I use a TENS unit on my ankle and it helps the pain a lot. Everyone is different. My first encounters with stim were at physical therapy sessions where they used the stim in combination with heat at the end of out sessions and it helped a lot. It's definitely something that I think I benefited from because my first uses were under the direction of someone who knew what they were doing. I know the right placements for the electrodes and I know at what settings and for what lengths of time to use them.

I have definitely found that the TENS unit helps if I can surround the area of pain with the electrodes which works usually when I have certain areas that flare up worse than others. It does not help in RSD areas where the pain is more generalized or covers a larger area. It helps with certain kinds of RSD pain (namely the flare ups and the bone crunching pain) but less with others (like the wide spread burning or hypersensitivity).

I'm sorry that you are suffering right now and hope you find some relief soon.