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Frog Kick
Finning techniques are the skills and methods used by swimmers and underwater divers to propel themselves through the water and to maneuver when wearing swimfins. There are several styles used for propulsion, some of which are more suited to particular swimfin configurations. There are also techniques for positional maneuvering, such as rotation on the spot, which may not involve significant locational change. Use of the most appropriate finning style for the circumstances can increase propulsive efficiency, reduce fatigue, improve precision of maneuvering and control of the diver's position in the water, and thereby increase the task effectiveness of the diver and reduce the impact on the environment. Propulsion through water requires much more work than through air due to higher density and viscosity. Diving equipment which is bulky usually increases drag, and reduction of drag can significantly reduce the effort of finning. This can be done to some extent by streamlining diving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave Diving
Cave-diving is underwater diving in water-filled caves. It may be done as an extreme sport, a way of exploring flooded caves for scientific investigation, or for the search for and recovery of divers or, as in the 2018 Thai cave rescue, other cave users. The equipment used varies depending on the circumstances, and ranges from breath hold to surface supplied, but almost all cave-diving is done using scuba equipment, often in specialised configurations with redundancies such as sidemount or backmounted twinset. Recreational cave-diving is generally considered to be a type of technical diving due to the lack of a free surface during large parts of the dive, and often involves planned decompression stops. A distinction is made by recreational diver training agencies between cave-diving and cavern-diving, where cavern diving is deemed to be diving in those parts of a cave where the exit to open water can be seen by natural light. An arbitrary distance limit to the open water s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Turns
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of STOL (Short TakeOff and Landing) or STOVL (Short TakeOff and Vertical Landing) aircraft cannot perform without a runway. In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production.Munson 1968.Hirschberg, Michael J. and David K. Dailey"Sikorsky". ''US and Russian Helicopter Development in the 20th Century'', American Helicopter Society, International. 7 July 2000. Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter, not to be confused with the single-blade monocopter) has become the most common he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backward Kick
Backward or Backwards is a relative direction. Backwards or Sdrawkcab (the word "backwards" with its letters reversed) may also refer to: * "Backwards" (''Red Dwarf''), episode of sci-fi TV sitcom ''Red Dwarf'' ** ''Backwards'' (novel), a novel based on the episode * '' Backwards: The Riddle of Dyslexia'', 1984 American TV program * "Backwards" (Rascal Flatts song), a 2006 country music song on ''Me and My Gang'' * "Backwards", a song by Apartment 26 from the '' Mission: Impossible 2 (soundtrack)'' * "Backward", a song by Quicksand from the album ''Manic Compression'' * Backmasking, a recording technique in which a sound or message is recorded backward onto a track that is meant to be played forward * " Sdrawkcab", a 1998 episode of ''Dexter's Laboratory'' See also *Other Backward Class The Other Backward Class is a collective term used by the Government of India to classify castes which are educationally or socially backward. It is one of several official classifications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monofin
A monofin is a type of swimfin typically used in underwater sports such as finswimming, free-diving and underwater orienteering. It consists of a single or linked control surface (fluid dynamics), surfaces attached to both of the diver's feet, emulating the Cetacea#Fluke, fluke of Cetacea, Cetaceans like whales or porpoises. The arrival of the monofin in the early 1970s led to the breaking of all finswimming world records by the end of the decade due to the improved performance possible when used instead of two ordinary swimfins. Use To differentiate between the use of monofins and conventional fins, the latter are sometimes referred to as stereo fins or bi-fins. The monofin swimmer extends arms forward, locking hands together, locking the head between the biceps, in a position known as Streamline (swimming), streamline position. The undulating movement starts in the shoulders, with maximum amplitude towards the hips; the legs almost don't bend to transfer the movement to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swimfin
Swimfins, swim fins, diving fins, or flippers are finlike accessories worn on the feet, legs or hands and made from rubber, plastic, carbon fiber or combinations of these materials, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, float-tube fishing, kneeboarding, riverboarding, scuba diving, snorkeling, spearfishing, underwater hockey, underwater rugby and various other types of underwater diving. Swimfins help the wearer to move through water more efficiently, as human feet are too small and inappropriately shaped to provide much thrust, especially when the wearer is carrying equipment that increases hydrodynamic drag. Very long fins and monofins used by freedivers as a means of underwater propulsion do not require high-frequency leg movement. This improves efficiency and helps to minimize oxygen consumption. Short, stiff-bladed fins are effective for short bursts of acceleration and maneuvering, and are useful for bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silt
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when dry, and lacks plasticity when wet. Silt also can be felt by the tongue as granular when placed on the front teeth (even when mixed with clay particles). Silt is a common material, making up 45% of average modern mud. It is found in many river deltas and as wind-deposited accumulations, particularly in central Asia, north China, and North America. It is produced in both very hot climates (through such processes as collisions of quartz grains in dust storms) and very cold climates (through such processes as glacial grinding of quartz grains.) Loess is soil rich in silt which makes up some of the most fertile agricultural land on Earth. However, silt is very vulnerable to erosion, and it has poor mechanical properties, making construction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolphin Kick
The dolphin kick is a kicking movement used in swimming. It is frequently used as part of the butterfly stroke and in underwater kicking. See also * Fish kick The fish kick is a method of kicking while swimming, generally used underwater. It was pioneered by the American Misty Hyman and has been cited as possibly the fastest stroke for humans. Procedure and effectiveness Fish kicking is a form of ... References Swimming {{Swimming-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flutter Kick
The flutter kick is a kicking movement used in both swimming and calisthenics. Swimming In swimming strokes such as the front crawl or backstroke, the primary purpose of the flutter kick is not propulsion but keeping the legs up and in the shadow for the upper body and assisting body rotation for arm strokes. The legs are extended straight backwards in line with the body. They are moved up and down, one leg kicking downwards (relative to the front of the swimmer's body) as the other leg moves up. The knees are slightly bent to facilitate the kicking action, but not too much in order to minimise drag created by the thighs as they move out of the shadow of the swimmer's body. Similarly, toes are pointed to minimize drag. The downward moving leg provides the thrust. An integral part of the kick is the flexing of the ankles; it is the flexing of the ankle that allows the foot to provide thrust. The knees are not kept rigid when kicking but are allowed to flex slightly to allow the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontal Plane
The coronal plane (also known as the frontal plane) is an anatomical plane that divides the body into dorsal and ventral sections. It is perpendicular to the sagittal and transverse planes. Details The coronal plane is an example of a longitudinal plane. For a human, the mid-coronal plane would transect a standing body into two halves (front and back, or anterior and posterior) in an imaginary line that cuts through both shoulders. The description of the coronal plane applies to most animals as well as humans even though humans walk upright and the various planes are usually shown in the vertical orientation. The sternal plane (''planum sternale'') is a coronal plane which transects the front of the sternum. Etymology The term is derived from Latin ''corona'' ('garland, crown'), from Ancient Greek κορώνη (''korōnē'', 'garland, wreath'). The coronal plane is so-called because it lies in the direction of Coronal suture. Additional images File:Coronal plane CT scan of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breaststroke
Breaststroke is a swimming style in which the swimmer is on their chest and the torso does not rotate. It is the most popular recreational style due to the swimmer's head being out of the water a large portion of the time, and that it can be swum comfortably at slow speeds. In most swimming classes, beginners learn either the breaststroke or the freestyle (front crawl) first. However, at the competitive level, swimming breaststroke at speed requires endurance and strength comparable to other strokes. Some people refer to breaststroke as the "frog" stroke, as the arms and legs move somewhat like a frog swimming in the water. The stroke itself is the slowest of any competitive strokes and is thought to be the oldest of all swimming strokes. Speed and ergonomics Breaststroke is the slowest of the four official styles in competitive swimming. The fastest breaststrokers can swim about 1.70 meters (~5.6 feet) per second. It is sometimes the hardest to teach to rising swimmers aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frog
A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is known from the Early Triassic of Madagascar, but molecular clock, molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 Myr, million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from Taxonomy (biology), taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes, anteriorly-attached tongue, limb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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