Swimming stroke

typically consists of repeating a specific body motion or swimming stroke to propel that body forward. There are many kinds of strokes, each defining a different swimming style or crawl.
In high school, collegiate, and Olympic swimming, there are two undulating strokes, and two alternating strokes.
Most strokes involve rhythmic and coordinated movements of all major body parts — torso, arms, legs, hands, feet, and head. Breathing typically must be synchronized with the strokes, too. It is possible, however, to swim by moving only legs without arms or only arms without legs; such strokes may be used for special purposes, for training or exercise, or by amputees and paralytics.

Swimming styles

Within a competitive sense particularly, swim stroke techniques are continuously changing to become either easier or more efficient as more people explore the activity.
A number of strokes are only used for special purposes, e.g. to manipulate an object, or just to stay afloat.

Underwater swimming

Swimming underwater is faster than swimming on the surface. Underwater swimming is not its own category in the Olympics, but in the 1988 Olympics several competitors swam much of the backstroke race underwater. After that, the Olympics created a rule that swimmers are only allowed to stay underwater for the first 10 meters after a start or a turn.
Any style with underwater recovery can be done underwater for certain distances depending on the need for air. Underwater swimming on the back has the additional problem of water entering the nose. To avoid this, the swimmer can breathe out through the nose or wear a nose clip. Some swimmers can close their nostrils with the upper lip or with the compressor naris muscles.
Swimming hydrodynamics have significantly applied BCF to techniques. In addition research on undulatory motion, undulatory Body-caudal fin anguilliform, and undulatory Median-paired fin give interesting conclusions. These natural modes are seen as an alternative to BCF techniques introducing some missing elements as buoyancy, gliding and floating to complement the scale of man’s hydrodynamics.
The study draws a conclusion from hydrodynamic properties of cephalopods as implied to human kinetics, discerning significant patterns, like floating, puddle, undulation or efficiency. In biomechanical aspect medusoid and anguilliform shows positive results: low Reynolds number, low viscous forces, stability, great laminar flow, linear momentum and efficient velocity.

Lifesaving strokes