I too am just back from a visit to a physio, having succumbed to Dexy5 's nagging about getting my niggles sorted out ….. (or was that nigging about naggles?)
After a quick canter through my last 12 months' running history, some laying on of hands and some exercises up against the wall, the verdict is that I am suffering from Achilles tendinopathy brought on by (shock, horror ) converting to midfoot striking after 67 happy years on my heels! Apparently my lower leg muscles, especially the right soleus, are struggling to adapt to the change, and my right Achilles is having to take up the slack.
Remedy - strengthening exercises 3 days a week but run at my discretion on the other days
. My man didn't suggest I should revert to heel striking, but did hint that changing away from it, if it came naturally, was maybe more last year's fashion choice than a scientifically supported decision - hopefully reporting that won't get me drummed out of the Brownies!