Kerrieann I wear fit flops al the time in summer, I have two pairs, when I first started wearing them, it make me ache more in the legs and lower back, this has gotten better and I noticed that they do firm up legs and tummy if you walk a lot. I don't think it has improved my hip and sacro illiaac joint that much though as I still have it but not to the degree it was six months ago.
Due to the ibuprofen scares I have stopped taking it ( not sure if this is a good thing or not)
What I have started taking is Boron ( started a month ago) and what I have found is my two little fingers that that had started aching and clicking have cleared up, from what I have read hip and lower back pain can take longer. Here is some info
http://actualcures.com/pain-relief-boron-hip-joint-pain-relief.html There is an awful lot of evidence to back Boron up and if you go to Google scholar you will find scientific research and conclusions.
It also increases estrodiol and testosterone and can act like an HRT for post menopause women. Its a cheap mineral to take and the cheapest is at Holland&Barrett, the dose is 3mgs a day.
These are the fit flops I wear the most as they have an elastic band strap, the others can be a bit uncomfortable on the top of your foot as they are not made very wide, you can get them on amazon
