I've had a tens unit for a few years. I got it prior to any of my surgeries for my nerve entrapment... prior to the RSD diagnosis. Mine is in my arm. I have also used it for my shoulder and neck which gets tight and painful. I find it has helped to a degree when it is on, but when I stop it the area feels weird. I wish I could come up with a better description than weird!

I rarely use mine. To me it ends up being more trouble than it is worth and has no lasting relief.