I got an epidural steroid injection in jan 2021 at s1. within 4 days my pain was gone however i started to have pretty consistent twitching in my legs/feet that have not stopped since. i am still pain free since the injection, is this related/normal?

I would guess that the ESI was due to a lumbar nerve compression, and now that this is relieved, nerve function is being restored. It is likely that your "twitching" is fasciculatory muscle activity, which is likely a favorable situation. Do inform your doctor, but if all else is stable, this should resolve soon.

This is not a typical response or reaction to an epidural steroid injection and may not be related to the injection itself. You should follow up with the health care provider who performed the injection who can review exactly what was done and what you should expect, and to evaluate your new symptoms.