How to systematically learn backstroke

What is backstroke?

Backstroke, also known as back swimming, is a swimming posture in which the human body is supine in the water. Backstroke includes anti-breast swimming and anti-climbing. Because the face is on the water, breathing is very convenient, but swimmers can't see where they are going and are likely to be wrong. Backstroke is the only athlete's position to start in the water, and everything else jumps into the water.

The production and development of backstroke technology has a long history. In 1794, there was a record of backstroke technology. However, until the beginning of the 19th century, backstroke strokes used both arms to stroke backwards at the same time, and the two legs did breaststroke. This is the current "anti-breaststroke." Since the technique of crawling in 1902, due to the reasonable and fast crawling technique, people began to use the two-armed crawling stroke to swim backwards. However, the current backstroke technology was not formed until 1921.

Backstroke technology is easy to breathe because the head is exposed to the water surface; lying on the water, it is relatively labor-saving. Therefore, it is deeply loved by the middle-aged and the elderly and the weaker.

Backstroke technical points are divided into four parts: backstroke body posture, backstroke leg technology, backstroke arm technology, and backstroke coordination technology.

First, backstroke body position

When swimming backstroke, the body should stretch naturally, supine on the water, the head and shoulders should be slightly higher, the waist and legs should be kept horizontal, and the longitudinal axis of the body should form an angle of attack of about 10 degrees on the horizontal plane. The waist and both legs should be Under the water (see photo).

The head posture plays the role of "rudder" in the backstroke technique and can control the body's left and right rotation. The head should remain relatively stable, do not shake up and down, but the neck muscles should not be too nervous, the back of the head in the water, the water level near the ears, the two eyes to see the top of the leg.

In the backstroke swimming in the waist position, the waist muscles should maintain moderate tension so as not to make the body excessively flat and hips to be in a supine position. Raised on the ribs, do not have chest. When fast-moving in, the body's angle of attack can raise the body position. Athletes with higher levels not only expose their shoulders and chest to the water, but also often expose their abdomen.

When the body rotates to swim backstroke, the vertical axis of the body should naturally roll along with the two-arm stroke. The angle of the scroll will be slightly different according to the individual's situation. The person with good flexibility of the shoulder joint will roll less, and vice versa. Large, usually about 45 degrees (see figure).

The purpose of body rolling:

1, is conducive to the water arm in a better angle, can strengthen the power of water

2, can maintain a certain depth of bending arm stroke

3, is conducive to arm out of water and move arm forward.

Note that the angle of rolling should not be too large, otherwise it will not only cause fatigue, but will also affect the speed of progress.

Second, backstroke leg movements

In the backstroke technique, leg movement is one of the factors that keep the body in a better angle and horizontal posture, and the kicking action not only controls the body's swing, but also generates a certain propulsive force.

The leg movements of the backstroke consist of the following pressure action and kicking action, ie straight leg compression and kicking of the leg.

The action of pressing down the pressing leg is done by the contraction of the hip muscles. In the entire leg press action, the first two thirds due to the resistance of the water, the knee joint fully developed and the leg muscles relaxed. When the leg press down to a certain degree, due to the control of the abdominal muscles and psoas muscles, stop down, and transition to the upward movement, due to the role of inertia, the lower leg still continues downwards, causing the knee joint to bend, so under the leg press The second third is a bent leg.

As the inertia gradually weakens and the leg kicks, the lower leg also starts to move upward, but at this time, the foot continues to continue downward until the inertia disappears. The thigh, calf, and foot end the downward movement once and form a downward “whiplash”. action.

The action of depressing does not produce propulsive force, so the relative speed required is not too fast, and the joints of the legs are naturally relaxed.

Kicking action When the leg action is pressed down, due to the resistance of the water to the lower leg and the thigh muscles, the thighs and lower legs form an angle of about 135-140 degrees, and the lower leg is about 40-45 degrees with the horizontal plane (see the figure below). .

At this time, the calf is bent to the maximum extent, and the calf and the foot are larger on the water surface. The beginning of the kicking action requires the use of the strength and speed of the foot, and gradually increases to the maximum strength and speed. When the leg moves upwards beyond the horizontal plane, the upward motion ends, and the knee joint approaches the water surface. Then the calf and the foot also turn upward one by one, which is the full extension of the knee joint, constituting a downward "whiplash" action (see figure 1 below).

The kicking action is carried out by the thigh driving the lower leg and the lower leg driving the foot, and in any case, try not to expose the knee or the toes. When kicking, the toe should be rotated inward to increase the water area.

Third, backstroke arm movements

Backstroke strokes are the main factors that drive the body forward. A complete arm movement is divided into several stages: entering the water, holding water, pushing the water, discharging the water, and moving the arms in the air. The palm forms an “S”-type route under the water due to water entering, holding water, and pushing water (see below). Figure).

When entering the water arm into the water, the arms should naturally relax with the inertia of the arm-lifting action. The water entry point should be between the longitudinal axis of the body and the extension of the shoulder, or on the extension of the shoulder. Too wide and too narrow can affect speed.

When the arm enters the water, the arm should be kept straight, and the elbows should not be bent. When entering the water, the small finger points downwards, the thumb is upwards, and the palm is laterally rearward. The palm and the arm are about 150-160 degrees.

Hugsing water is to create favorable conditions for pushing water. After the arm enters the water, the momentum generated by the use of the shift arm actively slides down to a certain depth, and the palm moves downwards and laterally. The shoulders, the elbow, the internal rotation of the upper arm, and the wrist-bending action are combined with the rolling of the body to make the palm. Align with the forearm and feel pressure. When the water-filling action is completed, the elbow flexion is about 150-160 degrees. The palm of the hand is about 30-40 centimeters in height, and the shoulder maintains a high position.

When holding water: the direction of movement of the hand is backwards - downwards - outward three minutes of movement, the water flow from the tip of the little finger to the first metacarpal bone, followed by an external rotation of the forearm, changing the direction of the palm, from the outward - - Downwards - Backwards - Backwards - Upwards - Outwards.

Stretching the backstroke of the backstroke is the main driving force behind the advancement of the body. The entire movement begins with the flexing of the arm and centering on the shoulder, straightening the lower side of the leg. The water pulling action includes two stages of pulling water and pushing water.

Pulling water is based on the arm's reach and water. At the beginning, the internal rotation of the forearm moves on the palm of the hand, and the elbow descends, which increases the elbow elbow. The palm and the small hand must keep perpendicular to the direction of advancement. When the palm of the hand is on the shoulder side, the degree of bending is the largest, about 70-110 degrees, and the palm of the hand is close to the water surface.

In the first half of pulling water, the movement of the hand is upward-outward-backward three points; the latter part is upward-inward-backward three-point movement. Water flows from the thumb to the popular pinkie. This stage is also the stage where the body rotates to the same side of the stroke arm.

Pushing the water begins when the arm is over the shoulder. The elbow joint and the big arm should gradually approach the body and push the water in the direction of the foot. When the pushing water is about to end, the inner arm rotates to accelerate the lowering of the wrist and the palm moves backwards and turns downwards. When the water is pushed, the movement of the hand moves inwards—downwards—backward movements gradually change into inwards—downwards—forward movements. The water flows from the little finger to the thumb. At the end of pushing the water, the arm should be straightened and the palm should be under the side of the thigh (see figure below).

After the water is pushed to the water, the rebound of the water pressure on the palm of the hand quickly raises the water. There are many types of hand when watering out: First, the first hand back out of the water; Second, the thumb first out of water; Third, the little finger first out of water. Each of these three types of hand has advantages and disadvantages, and the last one is relatively good.

Regardless of the hand-type water, we must pay attention to make the arm natural, relaxed, rapid, and to put the shoulder after the first pressure, shoulders exposed after the water, the shoulder by arm, arm and hand in turn out of water (see below ).

After the arm is lifted by the arm in the air, the hand should quickly move from the outside of the thigh to the surface of the water perpendicular to the shoulder. When the arm is moved over the shoulder, the palm of the hand is to be rotated inwards to flip the palm outwards (without this action using the pinky first exit technique). When the arm is moved in the air, it is necessary to straighten and relax. In the latter stage of the arm shift, it is necessary to pay attention to the full extension of the shoulder joint in preparation for entering the water and drawing water (see the figure below).

Fourth, backstroke technology

The cooperation of the arms of the two-armed backstroke technique is "connected", that is, when the stroke of one arm is over, the other arm has entered the water and starts to draw water; one arm is in the middle of the stroke, and the other arm is in the shift arm. Half of it. During the entire arm's movement, both arms are almost completely in the opposite position (see the figure below).

The breathing of the arm and the breathing in the backstroke is relatively simple, and it is usually a stroke of two strokes. That is, when you move your arm, you start to inhale, and then make a short breath, and exhale when the other arm moves. When swimming at high speed, there is also a technique to draw a breath once, but the breath cannot be too frequent, otherwise it will cause insufficient breathing and cause disorder.

Whether or not the arms and legs cooperate with the arm and legs is reasonable and will affect the balance and coordination of the entire movement. During the stroke of the arm, the upper kick and lower pressure of the leg must avoid excessive rotation of the body to maintain the balance and coordination of the body.

In the modern backstroke technique, six kicks and two strokes are commonly used to match the stroke (see the chart below). There are also a few people who use four kicks.

Backstroke arm leg action coordination table