Well, at least I now know why my right ankle has taken so long to recover from the trauma sustained at hour 21 of my last race.
And the answer is ...
for the last few weeks I have been suffering from gout.
That has been causing pain when running (and at other times) but, unusually, it is not the big toe joint which is affected but the ankle joint - very strange. But that's typical for me I suppose.
I haven't been running for a week or so to get this sorted out and now I have another week to let the drugs do their work before I can resume. Cycling and gym work continues though.
At this point I should say that I was quite worried at possible diagnoses which included cancer but ... now I know what's wrong and how to manage the situation I seem to have recovered my mojo.
Now I'm really looking forward to racing again next summer.