In reply to IainRUK:
> What Steff says, could be anything along the back chain so see a physio, and for now just start stretching.. nothing excessive but light stretching won't hurt.
> But could be anywhere from feet to glutes.. I had PF related to tight calts and weak gluteus..
Agreed, I started off with an IBT issue and by the end of physio, rolling and stretching I'd cleared up some niggling lower back pain and loosened off my hips / thighs making strides feel much more free.
When I stretch and roll I always do the whole system but target anything that might have been causing me issue. Just wish I'd been doing this 10 years ago!