Be sure to consider non-cycling issues, like posture and work setup. My chiro (who is also a PT) helped me figure out what was causing the issues. In my case, it was poor ergonomics at work, bad shoes, poor posture, weak core, too much driving, and a whole lot of personal and work stress. I've been able to address all those things, but it still flares up if I get lazy or stressed (or wear clogs).