I developed lower back pain from cycling around xmas time , which led to 7 weeks off work as unable to sit at a desk . I tried a chiropractor but the progress was very slow and expensive .
My back only really started to recover once i had been to a sports physio , who gave me a couple of simple stretches (tight hamstrings again) and very basic deep tissue exercises .
One of the best things i changed is holding a stretch for 30 seconds rather than 15 as this seems to be a lot more effective.
Also ,i exacerbated my injury by trying pilates exercises too soon ,which my back wasn’t strong enough for , so take your time . My back seems to benefit from keeping moving and only still get problems if sit still for a long time , but everyone is different !