Danger ranking: 5. "If you can twist them or fold them up and put them in your pocket, they're no good. There's no arch support and no lateral support. You may as well be walking barefoot."
Best for: "Lounging at the beach or the pool."
Avoid: Distances longer than the parking lot to the sand
Doctor's note: "I'm not sure if FitFlops give you the workout that they claim, but they have great arch support and heel lift. The back of the foot controls the motion of the front of the foot, so if you stabilize the heel, you also stabilize the arch and the forefoot. They also have a thicker sole, and raising the foot slightly off the ground helps you avoid glass and rocks. FitFlops are best for people who have already achieved some level of fitness—I wouldn't recommend them for those who are unstable in their gait."