Butterfly stroke body movement is a continuous undulating action that requires strength and power. When performed correctly, the movement provides the propulsion and drive needed to keep the overall stroke smooth and seamless.
The body should undulate from head to toe, producing a dolphin-type action. Correct body position and movement gives a smooth easy swimming stroke.
For an in-depth look at all aspects of butterfly including practical exercises to practice and help perfect the technique, download How To Swim Butterfly.
Although undulation is unavoidable, the body position should be kept as horizontal as possible to keep frontal resistance to a minimum. Intermittent or alternating breathing will help to maintain a smooth and steady movement.
The body should be face down (prone) with the crown of the head leading the action.
The shoulders should remain level throughout and the head should remain central and still, looking down until breathing is required.
Hips should be inline with the shoulders and should remain parallel to the direction of travel.
Although the movement initiates at the head, it begins as a relatively small movement when practised alone without the arm action. As the undulation progresses through the abdominal area and to the hips, the movement becomes larger and more pronounced.
The up and down movement of the hips are very much the driving force behind the undulating motion, finishing with a large bend of the knees and the powerful downward kick of the legs.
The head movement becomes larger and more pronounced when the breathing technique is added in time with the arm pull cycles.
The most common mistake made when performing the undulating movement is an excessive movement up and down.
As the movement originates from the head there is a tendency to over exaggerate this movement, causing the wave movement through the rest of the body to excessive and over pronounced.
The swimmer then puts more effort and energy into moving up and down instead of actually swimming forwards.
A simple push and glide exercise from the poolside followed by a gentle undulating movement across the surface of the water help to eliminate any excessive body movements.
If the swimmer places the effort on using the undulation to move forward then this will provide a solid base from which to build and perfect the swimming stroke.
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