Note
For the record, since BOC:
45 days off running (with a couple of fails early on)
25 days of 3xper day 2 sets of theraband exercises (hamstring curl and x country ski)
Plus front, back and side planks, supermans and 'nerve flossing' 1-2x per day.
Things have settled noticably but not totally and there still seems to be the odd bad day. Walking is now fine and biking seems fine too (even longer and harder rides).
Chiro's advice is to start a gradual return to running. Having been desperate to run for the last few weeks, I'm now a bit nervous about it as I don't want to bin all the good work. The plan is to be very cautious and back off if necessary. Let's see...