I am starting to see some renewed interest in the toning shoes niche. These are the shoes with design features that are designed deliberately to make the shoe unstable. This instability make the muscles work harder, giving the so called tone up. Players in this market include the Masai Barefoot Technology (MBT), Skechers Shape Ups and the Reebok EasyTone. Gone are the early claims for these shoes that they will cure things like cellulite. However, the claims that were still made for the benefits of these shoes have certainly been over-hyped, leading to some of the companies having to settle with the FDA for multi-millions of dollars. This was because the science did not support the health gains. That did not mean that the claims were wrong; it just means they were not supported by the evidence. The American Council of Fitness also came out with a report casting doubt on the benefits of the toning shoes. This lead to some waning interest in the use of these shoes.
However, more recently there has been a whole issue of the journal, Footwear Science, devoted to the science underpinning these shoes. A number of clinicians are reporting them useful for some selected conditions such as painful hallux rigidus. I have a heard of a few chiropractors who trial them in patients with chronic postural low back pain. While most of the research to date as focused on the biomechanical effects of toning shoes, what is need is more on the outcomes with these clinical conditions so we can be better guided as to when and who to use them in.
I certainly hope that toning shoes are not relegated to the history books as a result of litigation and some negative research findings, as they will have some good clinical uses. They are not going to be much use to tone the butt, however. I have been working on a related project. and an eBook.