Barbara:
First of all, get yourself to a reputable sports shop, and not Lady Foot Locker because the staff there do not know their products or what they are doing, in my experience.
You want someone to look at your feet naked to see what kind of feet you have, high arches, fallen arches, etc. They should take a look at the soles and heels of your street shoes to see the wear patterns to find out if you overpronate, etc. You should feel free to ask who the sneaker specialist is in the store and ask them to help you in this way. Your own special feet may contribute to pains you experience anywhere in your legs. If they can't do any of these things, and stare at you moronically when you mention it, do not open your purse/wallet in this store!
If you take a look in Health magazine of either last month or this month (check local Rite Aid to browse it there or your local library) and you'll see a whole article devoted to finding the right shoes for your feet.
Pain and aches in any part of the legs and feet that weren't there before but suddenly are is indeed one sign that the support in your sneakers is shot and those sneakers need to be retired to yard work, not impact exercise.
Personally I swear by my Rykas, but others like Reebok, or other brands. I bought the Ryka Cirrus last February 2002, paid $80 something for them and never regretted it. They have worked fabulously for me. Exactly one year later, this Feb 2003 I started to get again the pain in the soles of the feet and the arches that lead me to locate the shoe for me the year earlier and sure enough, I saw that the cushioning was indeed showing signs of stress and bought a new pair. Pain gone immediately. So I have learned my lesson. And I just don't like to take chances and mess around inviting injury, I haven't got time for it thanks.
$80 might seem a lot, but once a year (plus the cost of whatever new series Cathe brings out and cute workout gear from Marshalls!!!!) this is the cost of my health care and it's still way cheaper than any gym in the Ann Arbor, MI area!!!!!
My advice: don't mess around with your feet, get good cushioning. Go to ryka.com and see what they have.......
Clare