I hurt my back rowing in 2009 in the L5-S1 area. Many physios diagnosed it as different things and many of them tried different treatments. None of them worked and it hurt for three years. I tried lots of different core exercises, some physios tried manual and manipulative therapy (which helped for a bit) but after a few months of sessions of dry needling my back hasn't bothered me with that injury in over a year.
I would much recommend dry needling, it's not the same thing as acupuncture.