I have 2 medical conditions that cause me severe abdominal and lower back pain. Walking has been very difficult for almost 10 years, and I had resorted to using an electric scooter to get around for many errands and day trips. I had looked at the MBTs , but couldn't afford to buy them, knowing that there was a good chance they would cause more pain, but when I saw the less expensive Skechers, I decided to try a pair of the ShapeUps tennis shoes.  Within moments of putting them on, I was standing taller than I had in years, and also felt muscles working in my legs. After 2 weeks of wearing them according to the instructions, we took the kids to Disneyland. I used my scooter for  less than 1/4 of the time! I STOOD in lines! I wasn't sore, and when I woke the next day, I wasn't in so much pain I had to stay in bed to recuperate. IT WAS A MIRACLE!
I have since bought 2 more pairs, including the Mary Janes, and have turned my Mom, husband and 2 daughters into users, as well.  We're all just thrilled with the comfort and therapeutic aspects of these shoes. Well worth every penny, and so cute!
Watch the DVD, and pay attention to how you walk- it does take some getting used to until you learn the rhythm. But once you do, you'll feel the work-out aspect! Be prepared for some tender muscles at first... in a good way!
BTW- I have since tried the MBTs, and they feel identical, although more expensive. Not sure of the difference, but the Skechers definitely WORK!