A study by the American College of Sports Medicine performed a study on people that wear flip-flops and how they walk in them. The research proved that people that wear flip flops have to work much harder to walk while keeping the flip flops on at the same time, putting increased strain on the feet and legs. The study came about when they noticed that a large amount of students complained of foot pain after returning from summer trips.
The health of your feet can have a dramatic effect on the rest of your body, so it’s important to wear proper footwear. You don’t have to ditch flip-flops altogether though. Just don’t wear them unless you’re at the pool. You can read more and view a video about it here.