I can understand the walking issues. My wife power walks marathons and if I've been foolish enough to join her in training, I've ended up limping / skipping to keep up. The walking action seems to roll through the foot and off the big toe unlike my fore foot running action. My fell shoes are Inov8 Mudrocks and can't say they make any difference.
Just found this thread. I've been struggling with this for three years now and only today had a steroid injection to see if it might help. I'm 52, fat & running 2 marathons a year! Total milage approx 1500+ per year. A new joint was discounted and so was the fusion option, so went for the injection instead. I gave running club a miss tonight just to rest it as it's a bit sore.
I've been running on the outside of my foot for 12 months to compensate for the lack of toe movement & have suffered calf issues all year. The physio spotted the problem & recommended I take action.
I'll report in a weeks time & let you know hows it's going. It would be interesting to hear how others have coped with this.