I realised that my footwear made a real difference to how much my ankle would ache or even hurt after a run. The light shoes did not seem to create a problem. Having an explanation for the December sequence of pain-free runs was a big breakthrough.
I have been since working over the last 10 days on a gradual recovery programme.
Only this afternoon 7km into my "long" run (12 km) with everything going swimmingly, I twisted my bad ankle, again.
A passer-by was able to lend me a phone to call in help from my wife.
I do not know what this means - maybe it will be ok to resume again after a proper lay-off period on the same principles I have been working on.
What concerns me the most is that I am just not able to stay sufficiently focussed for long enough to avoid every rock and root, and I simply do not find on-road very exciting any more, especially now speed workouts and races are not really on my roadmap.