In reply to Donald82:
I've spent the last couple of days walking with a friend who uses a wheelchair. I've been going much slower than normal, and I've spent a fair bit of time standing around waiting because everything takes so much longer - toilet breaks, visiting shops, getting in and out of the car. I don't think I've really walked very far in absolute distance, but my instep, ankles and knees are in agony, I think just from the "wrong" pace for me and the standing around, a variation of shoppers back, maybe?