I've been a nurse for 8+ years and I'm in my mid-thirties. I have already begun to have foot and knee problems. I wore clogs for years, then when I had to start physical therapy related to chronic knee pain, I learned that for me, those were improperly fitting. PT has taught me that it all depends on the structure of your foot, your natural gait, etc. I now wear Zcoils. I soooo wish I had known about them earlier!! They force you to walk correctly, no matter how your foot is built. They are expensive, but they last a very long time and are worth the investment! Here's the website. Check it out. You'll be glad you did!
http://www.zcoils.com/