I saw Su Shen enter the acceleration position.

fast.

Dynamically adjust the tilt angle of the torso.

Incline from 55°→48° to activate the fluid mechanical effect.

Calculated according to the air resistance formula - F_d=0.5pC_dAv².

The change in the angle of the trunk can reduce the area facing the wind by 18%.

A larger normal force also helps maintain the body's mechanical balance in the vertical direction, ensuring the stability of the athlete's body posture during high-speed movement, so that athletes can more effectively convert muscle strength into forward propulsion force and achieve efficient acceleration.

Not to mention, reduce the windward area.

It can also make the body smoother.

The lumbar segment experienced a stepwise stretch with a phase difference of 15°.

The human spine is composed of multiple vertebrae, and the vertebrae are connected by intervertebral discs, ligaments and muscles.

During exercise, step-by-step stretching of the lumbar segment is an orderly motion pattern.

When the human body enters acceleration from its initial position, the nervous system will issue instructions to cause the muscles around the lumbar spine to contract in a coordinated manner.

Because the muscle attachment points and mechanical levers of each lumbar segment are different, under the action of muscle contraction force, the lumbar spine will stretch in a certain order and angle, resulting in step-by-step stretching with a phase difference of 15°.

This step-by-step stretching can enable the spine to better adapt to the body's posture changes and external forces during movement, while reducing the pressure on individual vertebrae and intervertebral discs, protecting the structure and function of the spine.

Why do you need this?

Of course, we need to use the principle of improving the efficiency of centrifugal-centripetal contraction of the iliopsoas muscle.

The iliopsoas muscle is an important muscle connecting the lumbar spine, pelvis and femur, and plays a key role in hip joint movement during running.

When the acceleration run enters, when the tilt angle changes, the body's center of gravity and mechanical environment also change.

The iliopsoas muscle first undergoes centrifugal contraction, that is, the muscle is lengthened under stress, and the muscles will store elastic potential energy during this process.

As the body moves forward, the iliopsoas muscle quickly converts into centripetal contraction, that is, the muscle shortens and generates strength, releasing the stored elastic potential energy and converting it into the body's forward momentum.

This is why you need to do it first when connecting it to the top - dynamic adjustment of the torso tilt angle.

Because this principle of improving the efficiency of centrifugal-centripetal contraction by using the iliopsoas muscle is not done well.

What Su Shen wants to use is to improve the rapid pedal and stretching power.

The acceleration zone needs to quickly increase the speed. The efficient contraction and transformation of the iliopsoas muscle can enable Su Shen to lengthen the muscles in advance through centrifugal contraction to store elastic potential energy.

Then quickly shrink the stored energy into a powerful pedaling force, pushing the body forward, so that each step of pedaling can generate greater propulsion force.

Then optimize your body posture.

The iliopsoas muscle works in concert with other muscles, and the improvement of its contraction and conversion efficiency helps maintain the body's balance and correct posture during the acceleration process.

Through efficient contraction, the iliopsoas muscle can better control the movement of the hip joint, make the body's center of gravity transition smoothly, and reduce energy loss.

That is, let yourself...use more energy to accelerate forward.

Cooperate with the enhancement of joint stability.

This is because during the acceleration process, the hip joint needs to withstand greater pressure and impact forces. The efficient contraction and transformation of the iliopsoas muscle can better maintain the stability of the hip joint, and through precise muscle control, the joints maintain the correct position and angle here.

Reduce joint shaking and damage risks.

Provides a stable foundation for exerting force on the legs.

So what is the basis?

Of course the answer is-

Further promote stepping!

Step frequency?

What is the relationship with the principle of improving the efficiency of centrifugal-centripetal contraction by using iliopsoas muscle?

relation……

It's big.

The iliopsoas muscle has high contraction and conversion efficiency, which can quickly complete the cycle of contraction and relaxation of the leg muscles, and speed up the swing of the leg.

The efficiency of iliopsoas muscle centrifugal-centripetal contraction conversion means that the muscle can complete the process from lengthening to shortening more quickly.

In the sprint acceleration zone, each step cycle includes the back swing of the leg, that is, the forward swing of the centrifugal contraction stage, that is, the centripetal contraction stage. This mode efficient conversion reduces the time spent in each stage, thereby shortening the entire muscle contraction cycle, and directly increasing the pace frequency within a unit time.

Can this work?

Of course it can do it.

Because the muscle contraction cycle is shortened.

And while doing this technical action.

It also has also been optimized for muscle mechanical properties.

This is because.

The mechanical properties of the iliopsoas muscle have a significant impact on the pace frequency!

Just like this step Su Shen is now.

During the centrifugal contraction stage, when the muscle is elongated, actin and myosin in the sarcomer interact to store elastic potential energy.

Efficient conversion efficiency means that muscles can store more elastic potential energy in a shorter time, and these energy can be released more effectively during the centripetal contraction stage.

According to the muscle mechanics model, this rapid release of energy increases the power output of muscle contraction, increasing the acceleration of leg swing.

At the same time, muscle viscosity is better regulated during the efficient conversion process, reducing energy loss within the muscles and making muscle contraction and dilation smoother.

Due to the fast shrinkage conversion speed, the legs can complete the back swing and forward swing cycles in a shorter time, thereby accelerating the overall swing speed.

Then increase the pace frequency.

There will be new possibilities.

certainly.

To this extent.

It's that simple, it's too easy to break through.

Su Shen’s activation is the only one among everyone.

In the case of a unique level, I want to go further.

It's like dancing at the pyramid.

The difficulty and complexity of breakthroughs.

They are all increasing exponentially.

Can.

terribly sorry.

This can stop everyone in the world.

I just can't stop Su Shen himself.

because……

His knowledge system.

He was not allowed to stop.

He is not allowed to stop.

After the above are done, the Achilles tendon superelastic effect is ready and can be activated as soon as possible.

Achilles tendon hyperelastic effect.

activation!

This chapter is not over, please click on the next page to continue reading! The Achilles tendon has super elastic properties. During the support period of the 100-meter acceleration zone, when the athlete's foot hits the ground, the weight of the body and the impact force generated by the movement make the Achilles tendon stretch.

During the short support period of 0.08s, the strain energy of Achilles tendon reached 6.2%, close to its ultimate elastic deformation threshold of 8%.

In this process, the Achilles tendon is like a spring, following Hooke's law F = kx, where F is the force acting on the Achilles tendon, k is the elastic coefficient of the Achilles tendon, and x is the deformation variable of the Achilles tendon.

According to the elastic potential energy formula E = 0.5kx², it can be seen from the calculation that the energy stored by the Achilles tendon during this process is about 42J.

This superelastic effect of the Achilles tendon is determined by its special biomechanical structure.

The Achilles tendon is mainly composed of collagen fibers. These fibers will be stretched and rearranged in an orderly manner when under stress, so that the Achilles tendon can store a large amount of elastic potential energy while bearing a large amount of tension.

When the stretching of the Achilles tendon reaches a certain level, the intermolecular force inside it will resist further stretching, ensuring that the Achilles tendon does not exceed its limit elastic deformation threshold, thus ensuring that the Achilles tendon can continuously and stably play the role of energy storage and energy release during repeated movements.

So.

In the 100-meter acceleration stage.

This storage and release of elastic potential energy is crucial to improving athletes' propulsion and exercise efficiency.
To be continued...