Many freestyle enthusiasts find that no matter how much effort they spend on hitting their legs, they can't walk too much, and they spend a lot of time on their legs, and they consume a lot of physical strength, but the effect of walking is still very poor. In fact, freestyle enthusiasts with this kind of problem are caused by irregular leg movements. The power of the freestyle leg stroke accounts for about 40% of the forward momentum, so it is important to solve the problem of leg power, otherwise the freestyle swimming will be more tiring and heavy only by the power of the rower to push the body forward.
First of all, let's analyze the principle of the propulsion force of the freestyle leg: the power of the freestyle leg is due to the "scissor legs" of the big and lower legs similar to the scissor action, and there is also an important power obtained by the "instep pressing water". Therefore, the forward force of leg beating is mainly composed of three parts of force formed by the "scissor leg" of the thigh, the "scissor leg" of the calf and the "instep pressing water".
Among them, the "scissor leg" of the unilateral thigh refers to the rotation of the thigh around the hip joint from top to bottom (in the state of the body prone on the water), at this time, the large retreat near the knee makes a larger rotation, and the root of the thigh makes a smaller rotation, so the "scissor leg" action of the thigh is generated, and the forward power is generated by the "water cutting" of the thigh. This force is the smallest of the three beating dynamics.
Similarly, the "scissor leg" of the unilateral calf refers to the movement of the calf around the knee joint from top to bottom, and the calf near the ankle makes a larger rotation, and the lower leg makes a smaller rotation near the knee joint, so the "scissor leg" action of the lower leg is generated, and the forward momentum is generated by the "water cutting" of the lower leg. This force is the second of the three leg punching powers.
Finally, when the calf is rapidly pumping water downward, the water resistance will have the opposite force on the instep, causing the foot to turn over backwards (only when the ankle is relaxed, this phenomenon will occur), and when the calf stops moving downward, the instep needs to recover forward, and the instep will naturally form a positive water pressing action, which is the instep pressing water action, which produces the power of the body to move forward. And this part of the motivation is precisely the main driving force for the leg to move forward. This force is the largest of the three leg-beating dynamics.
Now, it is clear that the motivation to move forward in freestyle is generated by the thighs, calves, and insteps, and then you need to tap out these motivations through practice, and the freestyle legs will go water.
Start with the "Instep Press" exercise, which needs to be completed by doing two exercises: "Ankle Stretch" on land and "Kick" in water.
1. Land "ankle stretching" exercise: stand in place with your feet together, cross your hips with your hands, and stand on your heels until your heels are the largest off the ground, hold for 3-5 seconds, drop your heels, and resume your movements. Do this movement in groups of 20 in a row, two sets a day.
2. "Kicking" exercise in the water: stand in the pool with one leg, lean on your side, and kick the ball with the other leg, at this time, you must let the ankle of the leg naturally straighten and completely relax the ankle. When you kick the ball, you will feel the pressure of the instep being pressed against the water resistance and be pushed back, and then the instep will recover at the end of the action. Then continue to swing your thighs back and repeat the above kicking movement, after 20 reps on one side, then another 20 reps on the other side.
After the practice of "ankle stretch" and "kick" in the water, and then practice prone retreat, it is easy to find the feeling of "instep pressing water" and "foot back flip".
Then do the leg beating exercises for the big and lower legs, the essentials of the action are: when the legs are swinging up (the body is prone on the water), you must keep the straight leg swing up, ensure that the upper and lower legs swing up synchronously, and stop swinging up when the toes come out of the water. Immediately after that, do the thigh down action, the thigh is slightly downward, relax the knee joint, make the calf naturally bend back, and complete the "scissor leg" action of the thigh; Immediately after the calf down action, at this time the two knees of the thigh are in a close position, and keep the thigh still, the calf around the knee joint force to quickly hit the leg down, the bent calf straightened, complete the calf "scissor leg" action. The two movements of hitting the big and lower legs should be completed in rapid succession without pausing during the actual practice. And always keep the ankles relaxed and the instep naturally straightened during the leg beating, and at the same time, be sure to pay attention to every leg beating action, and strive to make the instep feel that the instep is pressed by the water and turned back. When doing leg beats, you must not force the instep to straighten and make a "ballet foot", such an instep will not generate power.
The common problem of freestyle leg beating is that only the calf is bent to hit the water, and the thigh is basically not moving; There is also an excessive stiffness of the ankle and the appearance of "hoe feet". Both of these actions will lead to leg punches "not going water".
The freestyle leg exercise should be practiced 2-3 laps before each swim, and the rate is 60-70 legs per minute, and when the "three power" leg exercises are in place, the 25-meter freestyle leg should be completed within 35 seconds. If it exceeds 35 seconds, it is considered not up to standard, and you need to continue to practice and standardize the leg beating movements.