Thanks for the advice everyone, will try the frozen plastic bottles Stella1949 and those exercises SueDonim.
Sounds like it's a common thing, I had not heard of it until my friend at work has been struggling to walk with it.
I have just ordered some special insoles off EBay, Boots wanted £20+ so will try these EBay ones first.
Gillybob sorry you have it too, it's not nice, like you I enjoy walking and dread putting my feet to the floor at the moment. Got work later too, but hoping my Skechers will be ok, Im going to bike down to work, as its easier than walking at the moment.