Swimming is the self-propulsion of a person through water for recreation, exercise, or survival. Locomotion is achieved through coordinated movement of the body, or both. Humans can hold their breath underwater and undertake rudimentary locomotive swimming within weeks of birth, as a survival response. Swimming is among the top public recreational activities, in some countries, swimming lessons are a compulsory part of the educational curriculum; as a formalized sport, swimming features in a range of local and international competitions, including every modern Summer Olympics. Swimming relies on the nearly neutral buoyancy of the human body. On average, the body has a relative density of 0.98 compared to water, which causes the body to float. However, buoyancy varies on the basis of body composition, lung inflation, the salinity of the water. Higher levels of body fat and saltier water both lower the relative density of the body and increase its buoyancy. Since the human body is only less dense than water, water supports the weight of the body during swimming.
As a result, swimming is “low-impact” compared to land activities such as running. The density and viscosity of water create resistance for objects moving through the water. Swimming strokes use this resistance to create propulsion, but this same resistance generates drag on the body. Hydrodynamics is important to stroke technique for swimming faster, swimmers who want to swim faster or exhaust less try to reduce the drag of the body's motion through the water. To be more hydrodynamic, swimmers can either increase the power of their strokes or reduce water resistance, though power must increase by a factor of three to achieve the same effect as reducing resistance. Efficient swimming by reducing water resistance involves a horizontal water position, rolling the body to reduce the breadth of the body in the water, extending the arms as far as possible to reduce wave resistance. Just before plunging into the pool, swimmers may perform exercises such as squatting. Squatting helps in enhancing a swimmer’s start by warming up the thigh muscles.
Human babies demonstrate an innate swimming or diving reflex from newborn until the age of 6 months. Other mammals demonstrate this phenomenon; the diving response involves apnea, reflex bradycardia, peripheral vasoconstriction. Because infants are innately able to swim, classes for babies of about 6 months old are offered in many locations; this makes strong swimmers from a young age. Swimming can be undertaken using a wide range of styles, known as'strokes,' and these strokes are used for different purposes, or to distinguish between classes in competitive swimming, it is not necessary to use a defined stroke for propulsion through the water, untrained swimmers may use a'doggy paddle' of arm and leg movements, similar to the way four-legged animals swim. There are four main strokes used in competition and recreation swimming: the front crawl known as freestyle, the breaststroke, the backstroke and the butterfly. Competitive swimming in Europe started around 1800 using the breaststroke. In 1873, John Arthur Trudgen introduced the trudgen to Western swimming competitions.
The butterfly stroke developed in the 1930s, was considered a variant of the breaststroke until accepted as a separate style in 1953. Butterfly is considered the hardest stroke by many people, but it is the most effective for all-around toning and the building of muscles, it burns the most calories. Other strokes exist for specific purposes, such as training or rescue, it is possible to adapt strokes to avoid using parts of the body, either to isolate certain body parts, such as swimming with arms only or legs only to train them harder, or for use by amputees or those affected by paralysis. Swimming has been recorded since prehistoric times, the earliest records of swimming date back to Stone Age paintings from around 7,000 years ago. Written references date from 2000 BC; some of the earliest references include the Epic of Gilgamesh, the Iliad, the Odyssey, the Bible and other sagas. The coastal tribes living in the volatile Low Countries were known as excellent swimmers by the Romans. Men and horses of the Batavi tribe could cross the Rhine without losing formation, according to Tacitus.
Dio Cassius describes one surprise tactic employed by Aulus Plautius against the Celts at the Battle of the Medway: The thought that Romans would not be able to cross it without a bridge, bivouacked in rather careless fashion on the opposite bank. Thence the Britons retired to the river Thames at a point near where it empties into the ocean and at flood-tide forms a lake; this they crossed because they knew where the firm ground and the easy passages in this region were to be found, but the Romans in attempting to follow them were not so successful. However, the swam across again and some others got over by a bridge a little way up-stream, after which they assailed the barbarians from several sides at once and cut down many of them." In 1538, Nikolaus Wynmann, a Swiss professor of languages, wrote the first swimming book, The Swimmer or A Dialogue on the Art of Swimming. There are many reasons why people swim, from swimming as a recreational pursuit to swimming as a necessary pa
Free Colchian is the name of the swimming style from Georgia. This style was revived by the swimmer Henry Kuprashvili by swimming 2 kilometers using military-training style of swimming “Hands and Feet bound Colchian” on January 28, 2001. In 2002, for the first time in history, he swam across the Dardanelles Strait in 3 hours and 15 minutes using "Hands and Feet bound Colchian" on August 30. Henry Kuprashvili laid foundation of Georgian styles of swimming study process and established the school of swimming; the Georgian style of swimming comprises several styles unique to Georgia: “Lazuri”, “Hands and feet bound Colchian”, “Apkhazuri”, “Okribula”, “Iberiuli”, “Takhvia” and “Khashuruli” and “Kizikuri”. More traditional movements of the extremities are restricted or barred and forward motion is accomplished by dolphin-like undulation of hips and paired feet; these styles emulate the motions of mammals such as the seal, sea lion and beaver, which have evolved adaptations to water that enable them to attain an optimal swimming ability.
For those familiar with competitive swimming styles, Free Colchian most resembles the butterfly stroke, but with the arms remaining at the swimmer's sides. While swimming Lazuri or sport style: The legs are pressed together, the arms are pressed along the bodyline, the elbows should not jut out; the palms are touching the thighs. At the same time feet get out of the low position, the faster they leave the low position the weaker are the brake factors. Energetic blow is maximally powerful, forward sliding in water active and quick, which becomes more effective with energetic simultaneous movements, twice of joined feet; the swimmer should follow the stream, without making any rough movements in order not to “disturb” water and cause unnecessary excessive hydrodynamic resistance. The swimmer should be in such control of this process, as well as water, to avoid occurrence of excessive hindering waves.. In Lazuri swimming starts like Free style and butterfly, but at initial condition, while start and going into the water hands are moved up straight to the body Turning movement while swimming Lazuri is similar to that of the front crawl.
Hero of the Dardanelles: Seven Unique Developments. 2003. Editor-in-Chief: Prof. Doc. O. Gogiashvili. Tbilisi, Media-Holding Georgian Times, Text on Georgian and Russian languages UDC:796.092.2 + 797.2. Kuprashvili H. 2005. Georgian swimming. Textbook. Second publishing,Kutaisi State University, Kutaisi, ISBN 99940-0-561-8 УДК:797.2.034.2 + 797.2 Kuprashvili H. 2004. Georgian swimming. Textbook. Tbilisi, ISBN 99940-0-190-6. UDC: 797.2.034.2 + 797.2 Colchian-Iberian style of swimming "REUTERS 2007. The second traditional Tbilisi Sea group swimming... YouTube".] "Georgian Records Federation - Ana Lominadze's world record (CNN YouTube". Цанов Иван. Грузинци се състезават на техен плувен стил. The First Bulgarian Swimming Site Ivan Tsanov. Colchian-Iberian style of swimming… - The First Bulgarian Swimming Site.html первый чемпионат по древнему стилю плавания CNN-2002 CNN-2001 Competition in Georgian sport style of swimming „Free Kolkhuri" 2010
Quadrupedalism or pronograde posture is a form of terrestrial locomotion in animals using four limbs or legs. An animal or machine that moves in a quadrupedal manner is known as a quadruped, meaning "four feet"; the majority of quadrupeds are vertebrate animals, including mammals such as cattle and cats, reptiles such as lizards. Few other animals are quadrupedal, though a few birds like the shoebill sometimes use their wings to right themselves after lunging at prey. Although the words quadruped and tetrapod are both derived from terms meaning "four-footed", they have distinct meanings. A tetrapod is any member of the taxonomic unit Tetrapoda whereas a quadruped uses four limbs for locomotion. Not all tetrapods are quadrupeds and not all quadrupeds are tetrapods; the distinction between quadrupeds and tetrapods is important in evolutionary biology in the context of tetrapods whose limbs have adapted to other roles. All of these animals are tetrapods. Snakes, whose limbs have become vestigial or lost are tetrapods.
Most quadrupedal animals are tetrapods but there are a few exceptions. For instance, among the insects, the praying mantis is a quadruped. In July 2005, in rural Turkey, scientists discovered five Kurdish siblings who had learned to walk on their hands and feet. Unlike chimpanzees, which ambulate on their knuckles, the Kurdish siblings walked on their palms, allowing them to preserve the dexterity of their fingers. Many people practitioners of parkour and freerunning and Georges Hébert's Natural Method, find benefit in quadrupedal movements to build full body strength. Kenichi Ito is a Japanese man famous for speed running on four limbs. Quadrupedalism is sometimes referred to as being on all fours, is observed in crawling by infants. BigDog is a dynamically stable quadruped robot created in 2005 by Boston Dynamics with Foster-Miller, the NASA Jet Propulsion Laboratory, the Harvard University Concord Field Station. By NASA JPL, in collaboration with University of California, Santa Barbara Robotics Lab, is RoboSimian, with emphasis on stability and deliberation.
It has been demonstrated at the DARPA Robotics Challenge. Bipedalism Orthograde posture Family may provide evolution clue - BBC News
Backstroke is one of the four swimming styles used in competitive events regulated by FINA, the only one of these styles swum on the back. This swimming style has the advantage of easy breathing, but the disadvantage of swimmers not being able to see where they are going, it has a different start from the other three competition swimming styles. The swimming style is similar to an upside down front freestyle. Both backstroke and front crawl are long-axis strokes. In individual medley backstroke is the second style swum. Backstroke is an ancient style of swimming, popularized by Harry Hebner, it was the second stroke to be swum in competitions after the front crawl. The first Olympic backstroke competition was the 1900 Paris Olympics. In the initial position, the swimmer performing backstroke lies flat on the back. In backstroke, the arms contribute most of the forward movement; the arm stroke consists of two main parts: the recovery. The arms alternate. One complete arm turn is considered one cycle.
From the initial position, one arm sinks under water and turns the palm outward to start the catch phase. The hand enters downward pulling out at a 45 degree angle, catching the water. During the power phase the hand follows a semi-circular path from the catch to the side of the hip; the palm is always facing away from the swimming direction, while remaining straight as an extension of the arm, the elbow always points downward towards the bottom of the pool. This is done so that both the arms and the elbow can push the maximum amount of water back in order to push the body forward. At the height of the shoulders, the upper and lower arms should have their maximum angle of about 90 degrees; this is called the Mid-Pull of the power phase. The Mid-Pull phase consists of pushing the palm of the hand as far down as possible with the fingers pointing upward. Again, the goal is to push the body forward against the water. At the end of the Mid-Pull, the palm flaps down for a last push forward down to a depth of 45 cm, creating the finish of the power phase.
Besides pushing the body forward, this helps with the rolling back to the other side as part of the body movement. During the power phase, the fingers of the hand can be apart, as this will increase the resistance of the hand in the water due to turbulence. To prepare for the recovery phase, the hand is rotated so that the palms point towards the legs and the thumb side points upwards. At the beginning of the recovery phase of the one arm, the other arm begins its power phase; the recovering arm is moved in a semicircle straight over the shoulders to the front. During this recovery, the palm rotates so that the small finger enters the water first, allowing for the least amount of resistance, the palms point outward. After a short gliding phase, the cycle repeats with the preparation for the next power phase. A variant is to move both arms synchronized and not alternating, similar to an upside down breast stroke; this is easier to coordinate, the peak speed during the combined power phase is faster, yet the speed is much slower during the combined recovery.
The average speed will be less than the average speed of the alternating stroke. This stroke is called the elementary backstroke; this elementary backstroke swim was used in the 1908 Olympics. The backcrawl swim supplanted the elementary backstroke swim after 1908 as the competitive back swim and it is now the referred to as the backstroke. Another variant is the old style of swimming backstroke, where the arm movement formed a complete circle in a windmill type pattern. However, this style is not used for competitive swimming, as a lot of energy is spent on pushing the body up and down instead of forward. Furthermore, the added strain on the shoulder is considered less than ideal and can lead to injuries, it is possible to move only one arm at a time, where one arm moves through the power and recovery phases while the other arm rests. This is slow, but it is used to teach students the movement, as they have to concentrate on only one arm; this drill technique can work well with the swimmer holding a float, however it is important not to overuse this drill as a "paused stroke" can become habitual and can be challenging to unlearn.
The leg movement in backstroke is similar to the flutter kick in front crawl. The kick makes a large contribution to the forward speed, while stabilizing the body; the leg stroke alternates, with one leg sinking down straight to about 30 degrees. From this position, the leg makes a fast kick upward bending the knee at the beginning and stretching it again in the horizontal. However, there are frequent variants with four or only two kicks per cycle. Sprinters tend to use 6 kicks per cycle, whereas long distance swimmer may use fewer, it is possible to use a butterfly kick, although this is rare except after the initial start and after turns. The dolphin kick is essential for many top athletes, it may constitute the majority of the race. A great example of this is Olympic gold medallist Natalie Coughlin. Breaststroke kicks are most comfortable if the arms are used synchronized, as the breaststroke kick makes it more difficult to compensate for the rolling movement with alte
The butterfly is a swimming stroke swum on the chest, with both arms moving symmetrically, accompanied by the butterfly kick. While other styles like the breaststroke, front crawl, or backstroke can be swum adequately by beginners, the butterfly is a more difficult stroke that requires good technique as well as strong muscles, it is the newest swimming style swum in competition, first swum in 1933 and originating out of the breaststroke. The peak speed of the butterfly is faster than that of the front crawl, or freestyle due to the synchronous pull/push with both arms and legs, done quite fast, yet since speed drops during the recovery phase, it is overall slower than front crawl over longer distances. Another reason it is slower is because of the different physical exertion it puts on the swimmer compared to the freestyle, its name was taken from the butterfly. The breaststroke and front crawl can all be swum even if the swimmer's technique is flawed; the butterfly, however, is unforgiving of mistakes in style.
Many swimmers and coaches consider it the most difficult swimming style. The main difficulty for beginners is the synchronous over-water recovery when combined with breathing, since both arms, the head and part of the chest have to be lifted out of the water for these tasks. Once efficient technique has been developed, it becomes a fast stroke. Australian Sydney Cavill, son of the "swimming professor" Frederick Cavill, was 220 yards amateur champion of Australia at the age of 16 and is credited as the originator of the butterfly stroke, he followed his famous brothers to America and coached notable swimmers at San Francisco's Olympic Club. In late 1933 Henry Myers swam a butterfly stroke in competition at the Brooklyn Central YMCA; the butterfly style evolved from the breaststroke. David Armbruster, swimming coach at the University of Iowa, researched the breaststroke considering the problem of drag due to the underwater recovery. In 1934 Armbruster refined a method to bring the arms forward over the water in a breaststroke.
He called this style "butterfly". While the butterfly was difficult, it brought a great improvement in speed. One year in 1935, Jack Sieg, a swimmer from the University of Iowa, developed a kick technique involving swimming on his side and beating his legs in unison, similar to a fish tail, modified the technique afterward to swim it face down, he called. Armbruster and Sieg found that combining these techniques created a fast swimming style consisting of butterfly arms with two dolphin kicks per cycle. Richard Rhodes claims that Volney Wilson invented the'Dolphin' after studying fish, used it to win the 1938 US Olympic Trials, earning him a disqualification; the entire style is referred to as butterfly, but sometimes still called dolphin when referring to the dolphin kick. This new style was faster than a regular breaststroke. Using this technique Jack Sieg swam 100 yards in 1:00.2. However, the dolphin fishtail kick violated the breaststroke rules was not allowed. Therefore, the butterfly arms with a breaststroke kick were used by a few swimmers in the 1936 Summer Olympics in Berlin for the breaststroke competitions.
In 1938 every breaststroke swimmer was using this butterfly style, yet this stroke was considered a variant of the breaststroke until 1952, when it was accepted by FINA as a separate style with its own set of rules. The 1956 Summer Olympics were the first Olympic games where the butterfly was swum as a separate competition, 100 m and 200 m; the butterfly technique with the dolphin kick consists of synchronous arm movement with a synchronous leg kick. Good technique is crucial to swim this style effectively; the wave-like body movement is very significant in creating propulsion, as this is the key to easy synchronous over-water recovery and breathing. In the initial position, the swimmer lies on the breast, the arms are stretched to the front, the legs are extended to the back; the butterfly stroke has three major parts, the pull, the push, the recovery. These can be further subdivided. From the initial position, the arm movement starts similarly to the breast stroke. At the beginning the hands sink a little bit down with the palms facing outwards and down at shoulder width the hands move out to create a Y.
This is called catching the water. The pull movement follows a semicircle with the elbow higher than the hand and the hand pointing towards the center of the body and downward to form the traditionally taught "keyhole"; the push pushes the palm backward through the water underneath the body at the beginning and at the side of the body at the end of the push. The swimmer only pushes the arms 1/3 of the way to the hips, making it easier to enter into the recovery and making the recovery shorter and making the breathing window shorter; the movement increases speed throughout the pull-push phase until the hand is the fastest at the end of the push. This step is crucial for the recovery; the speed at the end of the push is used to help with the recovery. The recovery swings the arms sideways across the water surface to the front, with the elbows straight; the arms should be swung forward from the end of the underwater movement, the extension of the triceps in combination with the butterfly kick will allow the arm to be brought forwards relaxed yet quickly.
In contrast to the front crawl recovery, this arm recovery is a ballistic shot. The only other way of lifting th
The eggbeater kick is a style of kicking where the swimmer's legs alternate one-legged breaststroke kicks. This form provides continuous support; the eggbeater kick allows the swimmer to use their hands, remain stable in the water without swaying, maintain a constant vertical position, conserve energy. However, it can cause knee problems due to the circular rotation of the knee joint; the eggbeater kick is used in several different types of swimming activities. Water polo players use this style of kick so their hands can be free to shoot, pass and control the ball. Water polo players need to perfect. Goalkeepers must be able to do this as they need to have the power to get to the ball. Synchronized swimming uses this style of kick so they can perform other important skills that require stabilization; the eggbeater kick allows the swimmers to lift teammates out of the water. Lifeguards use this kick because it allows greater stabilization of the upper body and use of hands to rescue victims. In a schematized manner, a swimmer treading water using the eggbeater kick is: In a sitting position.
Swimmers learning this stroke use their hands to scull and tread water, as they attempt to achieve sufficient lift from the kick to remain afloat. The eggbeater kick can be seen as sculling with the legs, as it relies on the same fundamental physics; the eggbeater kick propels swimmers in an upward direction. The swimmer rotates his or her legs circularly while keeping their feet arched and angled, causing water above their foot to move faster than the water under their foot. Due to Bernoulli's principle, the faster-moving water has a lower pressure than the slower-moving water; this difference in pressure between the moving water and the surrounding water creates a force, propelling the swimmer upwards. The faster the swimmer's feet move, the more upward propulsion he or she receives
Treading water or water treading is what a swimmer can do while in a vertical position to keep their head above the surface of the water, while not providing sufficient directional thrust to overcome inertia and propel the swimmer in any specific direction. As it expends less energy than traditional strokes, it is used by swimmers to rest between periods of exertion without having to leave the water; as such, the phrase "treading water" has become a euphemism for an effort expected to create motion, but which results in staying in one barely sustainable, place. Any sort of movement that allows the swimmer to do this can be classified as treading water, but it is more efficient to move the arms and legs in a specific fashion. Drowning non-swimmers splash and kick in an effort to stay above the surface but their lack of technique along with shortness of breath and the panic factor make this a ineffective method of treading water, they will tire and not be able to stay above the surface long. More experienced swimmers find their own method of staying above the surface.
These techniques involve sculling, flutter kick, other unofficial techniques of staying above the surface. The eggbeater kick is a refined and efficient method of treading water, it involves the swimmer in a "sitting position" in the water. The swimmer's back must be straight, knees bent so that the thighs are parallel to the surface of the water, lower legs perpendicular to the surface; the left foot makes a clockwise motion while the right leg makes a counterclockwise motion towards the axis of the body, in a similar manner to operating the pedals on a bicycle. The legs should never meet because when one foot is on the inside of the motion, the other should be on the outside; the arms are not involved directly in this kick. The most critical aspect to having an effective egg beater kick is flexibility. You need good range of motion of the hips to have a good egg beater kick. Eggbeater kick can be used to move through the water; because of the opposite motion of the legs, eggbeater is a smooth and steady way of treading water.
It leaves the hands free to do work if necessary. This method of treading of water is the preferred method used by lifeguards and other aquatic rescue professionals because of its efficiency and simplicity; the fact that it does not occupy the hands is a major factor in this preference as these professionals have to perform first aid as they are swimming to safety. Eggbeater is used in water polo; the eggbeater kick is the primary kick that enables the player to support themselves in the water while passing, shooting and resting – horizontally and vertically. It is used for getting a quick, explosive start, when the player is beginning to swim. Greater elevation of the Polo player is created by a stronger eggbeater kick which results in a better rotation and stronger pass or shot. Overuse of the eggbeater kick has been a cause of knee injuries in water polo players. Eggbeater is used in synchronized swimming for stability and height above the water while leaving the hands free to perform strokes.
Using the eggbeater, swimmers can perform "boosts", where they use their legs to momentarily propel themselves out of the water to their hips or higher. The dog paddle is a simple style used instinctively by children, it involves waving both hands & legs randomly while "on all fours". Another popular style involves sculling water horizontally. List of swimming styles Spyhopping and momentarily staying out of the water by whales