Can pinched nerves in the back cause muscle twitching in the legs?

Yes- it is possible: It depends on what nerves and what muscles. If you were to say however the twitching is all over, it may not be fair to say it came from the back. Do you know if you have pinched nerves in the back, or do you have twitching only? Where is the twitching, and how much is there? Maybe start by answering those last two questions. Good luck!