I've been trying to get some exercise this week by taking long walks at lunch, but it appears to have backfired on me as I now can't put any weight on my right foot, particularly the heel. But late this afternoon I remember that this has happened to me once before, back when I was working at Hole's. At the time the doctor said I'd been doing too much walking on hard, flat surfaces - i.e. sidewalks and concrete. It wound up taking six weeks of physiotherapy to fix, mainly dipping my foot into alternating hot and icy cold water. Not much fun.