The lack of support provided by thong sandals is thought by some to be a major cause of injuries. Some flip-flops have a spongy sole, causing the foot to roll further inward than normal when it hits the ground (over-pronation). Flip-flops can cause a person to overuse the tendons in their feet, resulting in tendonitis.
Ankle sprains or broken bones are also common injuries, due to stepping off a curb or tumbling; the ankle bends, but the flip-flop neither holds on to nor supports it. The straps of the flip-flop may cause frictional issues, such as rubbing, during walking. The open-toed nature of the thongs may result in cuts, scrapes, bruises, or stubbed toes. Despite all of these issues, flip-flops do not have to be avoided completely. Many podiatrists recommend avoiding the inexpensive, drug store varieties and spending more on sandals with thick-cushioned soles, as well as ones that have a strap that’s not canvas and that comes back almost to the ankle.
Reading about this shocked me too, I would honestly say, little is more. Wear them, but not from the angle of an addicted soul.