Hope he doesn't want it back...

I got a book when I was at home called The Trigger Point Therapy Workbook. It's very specific about muscles and where they can get little tense knots, and the idea is that these tense points can "refer" pain to other places in the body. The book is very accessible, and uses all the right names for muscles. (For example, I know now how to massage my sternocleidomastoids!)

Anyway, there is a section on Morton's Foot, where the second metatarsal is longer than the first. Apparently I have Morton's Foot. You can read about it in the link, but the problem it causes is overpronation, and the fix is to put a pad under your first (but not your second) metatarsal. I tried that, and walking around today I could already notice a positive difference in how my feet felt. Very important, with all the walking I do around here.