Flip-flops (also called zōri, thongs, jandals, or a variety of other names throughout the world) are a type of open-toed sandal typically worn in casual situations, such as outside or at the beach. They consist of a flat sole held loosely on the foot by a Y-shaped strap that passes between the first and second toes and around either side of the foot. They may also be held to the foot with a single strap over the front of the foot rather than a thong. The name "flip-flop" originated because of the sound that is made by slapping between the sole of the foot and the floor when walking.
This style of footwear has been worn by the people of many cultures throughout the world, originating as early as the ancient Egyptians in 4,000 B.C. The modern flip-flop descends from the Japanese zōri, which became popular after World War II when soldiers returning to the United States brought them back. They became popular in casual settings during the 1960s, 1990s, and 2000s, and some varieties have even found their way into more formal attire, despite criticism.
The use of flip-flops can result in many pains and injuries, including ankle sprains and broken bones. Some individuals who walk for long periods report pain in the feet, ankles, and lower legs. The lack of support provided by flip-flops often results in over-pronation injuries, caused by the foot slipping inwards further than normal. This can lead to flat feet and tendonitis. Other injuries that may result are due to the footwear's open-toed nature, such as stubbed toes, cuts, and bruises. Doctors recommend purchasing pricier sandals with thick-cushioned soles, as well as those that have a strap that is not canvas and that comes back almost to the ankle.
The term flip-flop has been used in American and British English since circa 1972 to describe the thong sandal. It gets its name from the sound that is made by walking in them, and is thus an example of onomatopoeia.
This footwear has a number of terms around the world. In India and Pakistan, flip-flops are commonly known as hawai chappal (हवा चप्पल), which literally translates from Hindustani as "air sandal". The Japanese wear similarly designed, traditional straw sandals known as zōri. Throughout the world, they are known by a variety of other names, including dép tông or dép xỏ ngón in Vietnam, chinelo in Brazil, Jandals (short for "Japanese sandals") in New Zealand, japonki in Poland, sayonares (σαγιονάρες) in Greece, Schlapfen in Austria, slippers in Hawai'i, slops in South Africa, thongs in Australia, tsinelas in the Philippines, and vietnamki in Russia and Ukraine.
Thong sandals have been worn for thousands of years, dating back to pictures of them in ancient Egyptian murals from 4,000 B.C. One pair found in Europe was made of papyrus leaves and dated to be approximately 1,500 years old. They were worn in Jerusalem during the time of Jesus. These early versions of flip-flops were made from a wide variety of materials. Ancient Egyptian sandals were made from papyrus and palm leaves. The Masai of Africa made them out of rawhide. In India, they were made from wood. In China and Japan, rice straw was used. The leaves of the sisal plant were used to make twine for sandals in South America, while the natives of Mexico used the yucca plant.
The Ancient Greeks and Romans wore versions of flip-flops as well. In Greek sandals, the toe strap was worn between the first and second toes, while Roman sandals had the strap between the second and third toes. These differ from the sandals worn by the Mesopotamians, with the strap between the third and fourth toes. In India, a related "toe knob" sandal was common, with no straps but a small knob sitting between the first and second toes.
The modern flip-flop became popular in the United States as soldiers returning from World War II brought Japanese zōri with them. It caught on in the 1950s during the postwar boom and after the end of hostilities of the Korean War. As they became adopted into American popular culture, the sandals were redesigned and changed into the bright colors that dominated 1950s design. They quickly became popular because of convenience and comfort, and were popular in beach-themed stores and as summer shoes. During the 1960s, flip-flops became firmly associated with the beach lifestyle of California. As such, they were promoted as primarily a casual accessory, typically worn with shorts, bathing suits, or summer dresses. As they became more popular, some people started wearing them for more dressier or formal occasions.
In 1962, Alpargatas marketed a version of flip-flops known as Havaianas in Brazil. By 2010, more than 150 million pairs of Havaianas were produced each year. Flip-flops quickly became popular as casual footwear of young men and women from their teens to college. Girls would often decorate their flip-flops with metallic finishes, charms, chains, beads, rhinestones, or other jewelry.
A minor controversy erupted in 2005 when some members of Northwestern University's national champion women's lacrosse team visited the White House wearing flip-flops. The team responded to critics by auctioning off their flip-flops on eBay, raising $1,653 for young cancer patient, Jaclyn Murphy of Hopewell Junction, New York, who was befriended by the team. There is still a debate over whether this signaled a fundamental change in American culture — many youth feel that flip-flops are more dressy and can be worn in a variety of social contexts, while older generations feel that wearing them at formal occasions signifies laziness and comfort over style. In 2011, while vacationing in his native Hawai'i, Barack Obama became the first President of the United States to be photographed wearing a pair of flip-flops. The Dalai Lama of Tibet is also a frequent wearer of flip-flops and has met with several US presidents, including George W. Bush and Barack Obama, while wearing the sandals.
While exact sales figures for flip-flops are difficult to obtain due to the large number of stores and manufacturers involved, the Atlanta-based company Flip Flop Shops claimed that the shoes were responsible for a $20 billion industry in 2009. Furthermore, sales of flip-flops exceeded those of sneakers for the first time in 2006. If these figures are accurate, it is remarkable considering the low cost of most flip-flops.
Design and custom 
The modern flip-flop has a very simple design, consisting of a thin rubber sole with two straps running in a Y shape from the sides of the foot to the gap between the big toe and the one beside it. They typically do not have a strap around the heel, although heeled varieties are available, as well as flip-flops designed for sports, which come with added support common to athletic shoes, with the thong between the toes. Most modern flip-flops are inexpensive, costing as little as $5, or less in some parts of the world.
They are made from a wide variety of materials, as were the ancient thong sandals. The modern sandals are made of more modern materials, such as rubber, foam, plastic, leather, suede, and even fabric. Thongs made of polyurethane have caused some environmental concerns — since polyurethane is a number 7 resin, they can't be easily discarded or they will be in landfills for a very long time. Due to these concerns, some companies have begun to sell flip-flops made from recycled rubber, such as that from used bicycle tires, or even hemp.
Due to the strap between the toes, flip-flops are typically not worn with socks. Though, in colder weather, some people may wear flip-flops with toe socks. The Japanese commonly wear tabi with their zōri sandals, which is a traditional sock with a single slot for the thong.
Health and medical implications 
While flip-flops do provide the wearer with some protection from hazards on the ground, such as hot sand at the beach, glass, thumb tacks or even fungi and wart-causing viruses in locker rooms or community pools, their simple design is responsible for a host of other injuries of the foot and lower leg. In the United Kingdom in 2002, 55,100 individuals went to hospital with flip-flop related injuries. By 2010, there were 200,000 flip-flop related injuries costing the British National Health Service £40 million.
Walking for long periods in flip-flops can be very tough on the feet, resulting in pain in the ankles, legs, and feet. A 2009 study at Auburn University found that flip-flop wearers took shorter steps and their heels hit the ground with less vertical force than those wearing athletic shoes. Individuals with flat feet or other foot issues are advised to wear a shoe with better support.
The lack of support provided by thong sandals is a major cause of injuries. Since they have a spongy sole, the foot rolls further inward than normal when it hits the ground — an action called over-pronation, which is responsible for many foot problems. Overpronation may also lead to flat feet. Flip-flops can cause a person to overuse the tendons in their feet, resulting in tendonitis. The lack of an ankle strap that holds the foot in place is also a common reason for injury, as this causes wearers to scrunch their toes in an effort to keep the flip-flop in place, which can result 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 a little bit of extra money 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.
See also 
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- "Flip-Flop". Online Etymology Dictionary. Retrieved July 18, 2012.
- Khanna, Parul (October 3, 2009). "Hawai chappal the new fashion accessory!". Hindustan Times. Retrieved July 18, 2012.
- "Translation of "air sandal" from English to Hindi". Google Translate. Retrieved September 26, 2012.
- Richmond, Simon; Dodd, Jan; Branscombe, Sophie; Goss, Robert (February 2011). The Rough Guide to Japan. London: Rough Guides. ISBN 9781405389266.
- Key, A.J. "Jandals, Thongs, Flip Flops & G-strings". biggie.co.nz. Retrieved July 18, 2012.
- Ribeiro, Patricia (August 6, 2011). "Havaianas - Brazilian Flip Flops". About.com. Retrieved July 18, 2012.
- Kendzior, Russell J. (2010). Falls Aren't Funny: America's Multi-Billion-Dollar Slip-and-Fall Crisis. Lanham, Maryland: Government Institutes. p. 117. ISBN 978-0-86587-016-1.
- Kippen, Cameron (1999). The History of Footwear. Perth, Australia: Department of Podiatry, Curtin University of Technology.
- DeMello, Margo (2009). Feet and Footwear: A Cultural Encylopedia. Santa Barbara, California: ABC-CLIO, LLC. pp. 130–131. ISBN 978-0-313-35714-5.
- "The History of Flip-Flops". Peche Blu. Retrieved July 19, 2012.
- Cullen, Ed (2006). Letter in a Woodpile. Nashville, Tennessee: Cool Springs Press. ISBN 1591862493.
- Cain, Kathryn (July 30, 2010). "The Timeline: Flip-flops". The Independent. Retrieved July 19, 2012.
- Peterson, Amy T.; Kellogg, Ann T. (2008). The Greenwood Encyclopedia of Clothing Through American History 1900 to the Present. Westport, Connecticut: Greenwood Publishing Group. p. 372. ISBN 978-0-313-35855-5.
- Ward, Julie (September 13, 2005). "Next big step in team spirit: Flip-flops". USA Today. Retrieved July 19, 2012.
- "Appropriate? Obama Becomes First Flip-Flop President". Fox News. January 5, 2011. Retrieved July 19, 2012.
- Fermino, Jennifer; Hurt, Charles. (January 5, 2011). "That's quite a feet! Bam first flip-flop president". New York Post. Retrieved July 19, 2012.
- Lister, Richard (February 19, 2010). "Flip-flop diplomacy with the Dalai Lama". BBC News. Retrieved July 19, 2012.
- Weisman, Jonathan; Canaves, Skye (February 18, 2010). "Dalai Lama Meets With Obama". Wall Street Journal. Retrieved July 19, 2012.
- Bernhard, Blythe (June 18, 2009). "Flips-flops are bad for your sole". Seattle Times. Retrieved July 19, 2012.
- Bloch, Michael. "Recycling Flip-Flops". Green Living Tips. Retrieved July 19, 2012.
- Vasil, Adria (2007). Ecoholic: Your Guide to the Most Environmentally Friendly Information, Products and Services In Canada. Toronto: Random House Canada. ISBN 978-0-307-36613-9.
- Stoller, Debbie (2010). Stitch 'n Bitch Superstar Knitting: Go Beyond the Basics. New York City: Workman Publishing Company. p. 186. ISBN 978-0-7611-3597-5.
- Sosnoski, Daniel (1996). Introduction to Japanese Culture. Boston, Massachusetts: Charles E. Tuttle Publishing Company. p. 85. ISBN 0-8048-2056-2.
- Csomor, Marina (July 18, 2012). "Flip-flops present feet with a painful problem". CNN. Retrieved July 19, 2012.
- Wheldon, Julie (August 3, 2006). "Flip flops can damage your health". Daily Mail. Retrieved July 19, 2012.
- Borland, Sophie (July 29, 2010). "Flip-Flops 'injure 200,00 a year' costing the NHS an astonishing £40m". Daily Mail. Retrieved July 19, 2012.
- Shroyer, J.F.; Weimar, W.H. (Jul-Aug 2010). "Comparative analysis of human gait while wearing thong-style flip-flops versus sneakers.". J. Am. Podiatr. Med. Assoc. 100 (4): 251–7. PMID 20660875. Retrieved October 22, 2012.
- Shroyer, J.F.; Robinson, L.E.; Wiemar, W. (2009). "Influence of Thong Flip-Flops on Running Kinematics in Preschoolers". American Society of Biomechanics. Retrieved October 9, 2012.
- Shroyer, Justin (September 9, 2009). Influence of Various Thong Style Flip-flops on Gait Kinematics and Lower Leg Electromyography. Auburn, Alabama: Auburn University. pp. 31–52.
- Willingham, Val (August 6, 2010). "Flip-flops aren't always easy on the feet". CNN. Retrieved July 19, 2012.
- Yara, Susan (May 4, 2006). "Skip the Flip-Flops". Forbes. Retrieved July 19, 2012.
- Watson, Nicole (July 18, 2012). "Study: Comfortable flip-flops causing painful health risks". ABC Action News. Retrieved July 19, 2012.
- "Doctors Warn About Flip-Flops". www.click2houston.com. October 10, 2011. Retrieved July 19, 2012.