Current Pedorthics | July-August 2018 | Vol.50, Issue 4 | Page 21

In most developing countries, sponge flip-flops are the cheapest footwear available – especially the thin EVA die-cut sole variety with two simple straps running in a Y from both sides of the forepart to join between the first and second rays. To reduce cost, Flip-Flops are even made from recycled tires – typically costing less than $1 at retail. Another common form of ‘upper’ treatment on the flip-flop is a simple strap across the forepart. In more developed countries the flip-flop has evolved from typically disposable seasonal footwear into a fashion statement. Flip-flops can now be found in expensive shoe stores decorated with jewelry, rhinestones or embroided designs. It appears that the flip-flop has crossed over from casual pool attire to dress wear. MO RE FLOP THAN FLIP? Typically, flip-flops have a soft spongy flat footbed, so when the foot strikes the ground there is no support or control during the pronation phase of gait. An unsupported arch during pronation tends to invert and flatten – leading to overpronation, which causes excessive internal rotation of the lower leg. Hence problems such as tendinitis, medial knee pain, hip pain and lower back pain. Continual overpronation of the foot also results in flat feet, especially if flip-flops are worn throughout childhood and adolescence when the muscles, bones and tendons of the feet are growing and underdeveloped. Due to the open nature of flip-flops, the wearer is more susceptible to stubbed toes, nail damage and overexposure to the environment. Some underfoot protection is afforded by the flip-flop from the dirt and heat but little else. On the thong model, the Y shaped straps between the first and second toes help to prevent the foot from sliding forward. The wrap-around strap design offers some medial and lateral control in the forepart but as the strap loosens and stretches out it will not prevent the foot from slipping forward inside the shoe. This can cause excessive friction and soreness on the plantar surface of the foot. Both Y Thong and Forepart Strap uppers tend to break or stretch more easily than regular sandals. Another common complaint leveled against the flip-flop is overexposure to the elements allowing too much sun and air to the feet, which can cause the feet to dry out and crack especially around the heels. While this is true of the common inexpensive flip-flop, this footwear style has evolved and there are a number of models on the market "In more developed countries the flip-flop has evolved from typically disposable seasonal footwear into a fashion statement." Current Pedorthics | July/August 2018 19