I Have Had Sciatic Pain For 7 Years, But Recently

I have had sciatic pain for 7 years, but recently became much more painful in the back of my right leg down to my calve. I have had 3 cortisone shots at a pain clinic, Physical therapy, and the last 2 weeks have had acupuncture treatment. None of the treatments have aleviated the pain. Would a EMG test be of value?