Another anecdote: walking 4-5 miles a day for 20 years and my feet are a wreck.  I finally found shoes (MBTs) that allowed me to continue walking.  About 5 years ago I was afraid I&#x27;d have to stop.<p>My knees are actually better, though.  I&#x27;ve had 3 operations on my left knee and if I don&#x27;t walk it gets very arthritic.  With walking, it&#x27;s fine.