Front crawl techniques (in detail)
Once you have mastered the streamline position, it is time to move on to the two major aspects of swimming. Front crawl has a very distinct pull which requires you to make an S-pull underneath the water along with a strong, continuous kick to propel you in the water. The swimmer relies primarily on his arms to provide more a propulsive force, but when the pull and kicks are combined, the swimmer is at his most efficient. Also, as stated earlier, Newton's third law of action-reaction connects into the concept of pulling down the water and the water creating an upward buoyant force as a result. Along with a similar concept, by having an effective pull, you are further allowing your body to have a greater force to push you forward throughout the water. Another aspect of the freestyle to consider is the form of your pull. It is more efficient to swim freestyle with a slight S-pull rather than propelling through the water with a straight, pulling arm. Also, your hand must have a cupped position in order to grasp most of the water backward. This creates a larger surface area to produce a greater force. (Hensley)
The Kick
There are two purposes as to why mastering an efficient kick is important: it provides a sense of balance to your body while performing the stroke, and also provides force to push you forward in the water. The position of your feet is very crucial in order to achieve this. You must have pointed feet (or what I like to teach my kids, "point your feet like a ballerina) in order to maximize your propulsion. The angle of your feet produces a forward motion as a result of your feet having contact with the water, which therefore produces an opposing force in that direction. (Hensley)
However, when you are swimming underwater (ex. after somersault from wall OR diving into pool), you use a dolphin kick instead of a flutter kick. Dolphin kick requires you have your legs together, while getting the necessary propulsion with the repeated, wave-like motions that is originating from your hip. (Hensley)
Although it is commonly believed, kicking "assists a swimmer to travel forward more by reducing the vacuum or suction behind them than it does by providing forward thrust". This entails that your legs create a turbulence that makes it easier to swim by continuously kicking to break the tension of the water. (Hensley)
Although it is commonly believed, kicking "assists a swimmer to travel forward more by reducing the vacuum or suction behind them than it does by providing forward thrust". This entails that your legs create a turbulence that makes it easier to swim by continuously kicking to break the tension of the water. (Hensley)