Thank you so much! I've seen other runners ailments mentioned a lot, but not MN.
I swear this problem was caused by switching from my natural toe first stride to a heel strike many years ago (stooopid running magazine!). I've been trying to switch back, and it's hard. I found your website and began doing the ankle jumps a few days ago. Imagine my surprise when, that very night, I came upon your name in Born to Run. :)