Butterfly is one of the swimming events. The butterfly stroke technique evolved from the breaststroke technique. When the breaststroke technology developed to the second stage, that is, during the period from 1937 to 1952, in swimming competitions, some athletes used the technique of paddling their arms to their thighs, lifting them out of the water, and then migrating from the air. From the appearance, it looked like The butterfly spreads its wings and flies, so people call it "butterfly swimming". The butterfly stroke was the last to develop among the four competitive swimming styles. Because its leg movements resemble those of a dolphin, it is also called "dolphin swimming." The posture of the butterfly stroke is very similar to the legendary "mermaid".
Butterfly Leg Techniques
During the butterfly stroke, the legs should be brought together naturally and the heels should be slightly apart to form an "inward figure". When the legs are kicked downward in the previous stroke cycle After finishing, both feet are at the lowest point, the knee joints are straightened, the hips are raised to the water surface, and the hip joints are bent to about 160 degrees.
Then straighten the legs and move upward, gradually expand the hip joints, and sink the buttocks.
When the legs continue to move upward, the thighs begin to press down, the knee joints press down with the thighs, and the movement naturally bends, and the thighs continue to accelerate downward.
As the degree of knee flexion increases, when the feet are raised close to the water, the hips drop to the lowest point. When the knee joints are bent to an angle of about 110-130 degrees, the feet are raised to the highest point and downward accurately. Fetch water from behind.
When your feet push water downwards, relax your ankle joints, straighten your feet, and then push the water back and down with your calves and thighs accelerating. Both feet continue to accelerate and push water downwards. Before the movement is over, the thighs begin to move upward again. When the knee joints are fully straightened, the downward kicking movement ends.
The kicking action of the butterfly leg is driven by the waist, passes through the hip, knee, and ankle joints, and is completed in coordination with the movements of the trunk and spine. The direction of movement of the foot is downward and backward, and its downward amplitude is greater than its backward amplitude.
When the leg is lifted upward, the knee joint must be straightened. If it is slightly bent, the back of the calf will produce great resistance. In addition, when lifting your legs upward, do not use too much force to reduce resistance. The focus of the kick should be on the downward movement of the water. The speed of the downward movement of the leg should be more than twice as fast as the upward movement of the leg.