Good Evening. I Am Trying To Figure Out Why My

Good evening. I am trying to figure out why my back keeps flaring up. I was diagnosed with a lumbar sprain 3 weeks ago and treated with 2 courses of steroids and naproxen and it felt better and out of nowhere I am down with my back. Would a lumbar sprain do this or should I be concerned with a herniated disk? The pain radiates down my right leg causing weakness.