Stability shoes are part of a growing wave in fitness footwear, touting muscle toning as a benefit. Doctor Kendrick Whitney says, "They're interesting because the idea is they are trying to create a more natural barefoot environment walking on unstable terrain, like sand." So do they work? "Research has shown that these really give a very good workout to lower extremity muscles, calf muscles, thigh muscles, core muscles, also abdominals, buttocks, gluteals." According to Doctor Whitney, that toning is thanks to a design that veers away from sole stability and instead puts you off balance. "It strikes at a much more severe angle, rolls through and then off, which gives much more motion and exercise to the leg muscles in the sagittal plane, or side to side." That wobble, though mostly beneficial, can be hazardous. "We certainly don't want to use them if they have vertigo, dizziness; an unstable shoe could really create a situation that could cause falls." And take time to adjust to the new feel. "Perhaps 25 minutes a day, and gradually getting used to it. Certainly not wearing these for long periods right out of the box." The shoes range in price from $50 to $100.