Today's walking hasn't upset my knees at all so I decided to do a very short run. Altogether I went 3.4km with walking all of the sections that were clearly downhill. The 'level' bit was undulating and I took care not to slow myself downhill. Throughout I tried to be very gentle on my feet with no heel striking. I tried to be aware of my potential cross-over gait and made an effort to keep my feet under my shoulders - every so often I felt tendency to step differently. I also checked my cadence. Early on it was 160 but with a bit of effort I managed 180; but that felt very fast.
Rollering and stretching was fine - a bit of a knot in my left calf. Let's see how things are tomorrow.