What's the fastest and most effective way to treat lower back pain?

Co-Founder at sablier.com, and open-source developer. I have a broad range of interests, including longevity, epistemology, physics, and psychology.

no simple answer, because "lumbar pain = complex": depends on where it emanates from: disk? SI-joint? Fascia? Sciatia nerve? 
What helps in most cases is 2-3 hours of walking per day, hanging from a bar, and reading the classic Myofascial Tension Syndrome Book, which was a game changer for me.