I've always had problems with my feet and legs, so I'm probably just paranoid about it. No way I could walk that much on a regular basis without surgery.
If you can't walk the equivalent of five lengths around a standard track without stress fractures you have a serious, debilitating disease and should see a doctor immediately.
Isn't a standard track only ~a quarter mile (400m)? With a 40 lb pack, twice a day, plus hills, on young bones, with poor judgment about balance and weight placement, someone's going to get hurt. Stress fractures didn't seem implausible, though I suppose ligament injuries are more likely?
And yes, every specialist I've been to has said all I can do is try to protect my joints until I eventually decide I want surgery.
