Researchers found when you wear flip-flops, your toes fight to grip the shoe, making the muscles on the front of your shins work harder. Flip-flops were also found to shorten a person's stride. All of this can cause sore feet, ankles and legs when worn during a long period of time.
Researchers say flip-flips should only be worn during a short term basis and should be replaced every three to four months. Researchers also advise wearing models that hold your feet in place, like ones with heel cups and arches.
The study was presented at the annual meeting of the American College of Sports Medicine.