Hi there....Yes...it's night and day from an EMG....what type injection are you having? Is it with the flouroscope or x-ray?...and are they just using steroids in the shot?
The good part about injections are that they not only provide the steroid...the needle itself will 'break up' the inflammation caused by the proteins and chemicals in our body.
I also felt just 'pressure' and a very small amount of soreness from the needle afterwards...they were done in my cervical region...and was fine by that evening without any type of pain.
The one thing that I didn't pay attention to in the literature, was that steroids cause some people to have insomnia...so I felt pretty wired for a few days and had trouble sleeping...the good side was having plenty of energy!..LOL..
You should be good to go for anything you need to do the next day...Of course ask your Dr. to verify...
Keep us posted