Thats funny to hear, I've been back to the running shop and they are suggesting I lace my shoes tighter. My left ankle was quite badly sprained about 8 months ago and it's still getting back to where it needs to be. With every run the numbness is taking longer to come, Initially it was after 2 miles, now it takes 4 for it to come in, better then having screaming calf muscles either way.
Adrian, I am doing BMF (British Military Fitness) classes 2-3 times a week as well to do more general fitness stuff. They seem to work very well, I am quite frankly delighted, I have gone from no more then 2 miles at the start of Jan to 5 miles wishing I could keep going further by now. The only thing stopping me is a desire to avoid injury.