I had an EMG done many years ago. I don't remember which year but it was sometime during those first 1-2 years after I got sick in 1990 so probably 1992. For all I know the test has been modified since then so keep that in mind.
In my case EMG testing was done with small probes inserted into muscles in different areas. Some areas hurt a lot more than others. Testing on my hand and arm, little to no pain. Testing on my lower back, or on the top of my foot, lots of pain.
My suggestion is to ask the technician(?) (person who administers the EMG test) to give you some rest time between test areas. So, test your arm and then rest a bit, test your back, then rest a bit, etc.
I was lucky in having a very understanding person doing the test. He said that all the people who gave the test had to have it done on themselves first so they would know how it feels and so he understood that the could be painful for some people.
I also found this comment (source =
https://teleemg.com/patient-forums/)
Can I ask for some pain medication?
Different labs have different policies about pain medication. Some physicians may recommend you take two Aspirins or Tylenols before the test. Others may mail you a prescription drug to take an hour before the test. Sometimes you may be given an injection prior to the test. It is common however, that no sedation is given in any form since in most instances, patients wish to return to work or other regular activity after the test is completed. Another reason for not giving sedation is that you should always have someone accompany you to drive you home after receiving sedation and this is not always easy to arrange.
Everyone is different so I'm hoping the test won't be painful for you. Best of luck!