sprintstar, when I was young (400m PB 46,xx) , I often had problems with my Achilles tendons. I tried many things (Ice, cremes, strains/Dehnungen ), but only rest/break (ca. 2 weeks) and training on grass helped.
Reason for the problems where training on a very hard Tartan (?) track.
Onions: Ten years ago, I read it in a book. At this time, I had again problems - lasting for months - with my Achilles tendon, although I only played soccer one or two times a week. A German physiotherapist (Dieter Trzolek), who supervises German Soccer Teams (Bundesliga: 1. Fc Köln (Cologne), Bayer Leverkusen) published it in a book:
Trzolek, Zittlau: Die natürliche Sportlerapotheke: Die besten Hausmittel für Fitness und Leistungssteigerung
You have to cut onions in slices and press the slices onto the Achilles tendon. You can fix it with mull/gauze (or in socks).
This procedure I did three nights and after this all problems were blown away.
Ok, it's stinking horrible, my wife wasn't amused.