In reply to davie.p.: I got the same diagnosis last week, but it is something that is largely due to badly damaging my heel many years ago, and re-occurs on a fairly regular basis.
I find that I can still rock climb, (and hopefully ski as I am away all next week ) even when walking is a problem. As long as the weight is on the front of the foot and not on my heel I seem to be able to cope.
My problem re-occurred after a hard walk on Xmas Eve, another attempt to start to get myself fit for some winter climbing, but it looks as through I am still constrained to roadside cragging.