I also wanted to add that heat or soaking in a hot bath helps my muscle spasms a lot! I also use a muscle relaxer every night a couple of hours before bed.
An MRI may be helpful in diagnosing the problem. Chiropractors have their place, but I wouldn't trust any chiropractor to do treatment with out knowing what the problem is.
I went to a chiropractor at first. I was told I had a strained muscle and she did some stuff to my back. As it turns out, I have a spinal fracture, one of my vertebrae is slipping forward, and I have 2 problem discs. (I found this out after referring myself to an orthopedic doctor). I am getting ready for surgery. The chiropractor could have done a lot of harm to me. You live and learn I guess.