He is a tiger-level player.

Still a giant.

There is actually no difference at this time.

They all have to make way for these two people.

These two people were as expected.

They were directly confronted head-on.

Su Shen has another killer move here.

As mentioned before, the previous technical connection technology nodes.

In fact, they are just a front.

Now we are about to start making real killer moves.

This is...

Three-dimensional ground reaction force regulation!

What is three-dimensional ground reaction force regulation?

When an athlete's feet come into contact with the ground, interaction will occur. According to Newton's third law, the ground will give the athlete a reaction force of equal size and opposite direction, that is, the ground reaction force.

This force can be decomposed into three dimensions: vertical direction (Fy), horizontal direction (Fx) and front-rear direction (Fz).

Vertical force (Fy) is mainly used to support the athlete's weight, overcome gravity and realize the body's airflow.

Horizontal force (Fx) is the main source of motivation to drive athletes to accelerate forward.

The force (Fz) in the front and back directions is relatively small, but it also plays an important role in maintaining body balance and stability.

The relationship between three-dimensional ground reaction force and sprint performance is-

Vertical direction:

A larger vertical ground reaction force can allow athletes to obtain a greater upward impulse at the moment of touching the ground, which helps to shorten the support time and increase the aerial height and time, thus creating better conditions for the next step of pedaling.

For example, the peak of the vertical ground reaction force of an excellent sprinter at the moment of taking off is high, and he can quickly push his body off the ground and achieve an efficient airflow stage.

Horizontal direction:

The horizontal ground reaction force directly affects the athlete's acceleration and speed. By increasing the horizontal pushing force, athletes can obtain greater forward propulsion force, thereby increasing the speed of starting and running on the way.

Research shows that in the acceleration stage, the magnitude of the horizontal ground reaction force of sprinters is positively correlated with the acceleration, and in the maximum speed stage, the maintenance of the horizontal force is crucial to maintaining the stability of the speed.

Front and rear direction:

Although the front and rear forces are relatively small in value, they play an indispensable role in maintaining the body's lateral balance and stability. During the sprinting process, athletes need to fine-tune the front and rear forces to maintain the body's linear motion on the track, avoiding wasting energy or affecting speed due to lateral deviation.

Then now do you understand a little?

Combined with the front of Su Shen in the plateau.

Reasons for constantly rushing to related technical nodes such as vertical forces and horizontal components.

That's right.

That's just a little trial.

A real connection point.

It's here.

During the starting stage, athletes use the rapid contraction of leg muscles through the squat starting position to push the ground back and downward, thereby obtaining a large horizontal ground reaction force and allowing the body to quickly obtain initial speed.

At this time, the reaction force on the vertical ground will also increase accordingly to support the body to quickly lift it from a low posture.

Research from Sushen Laboratory shows that the peak of the horizontal component of the ground reaction force in the starting acceleration stage is about 1.46 times that of the maximum speed stage, highlighting the key role of the horizontal force in the starting stage.

Entering the acceleration stage, the horizontal ground reaction force continues to drive the athletes to accelerate. As the speed increases, the vertical ground reaction force also needs to be maintained at a certain level to ensure the stability of the body and the aerial height, creating conditions for subsequent pedaling.

At this stage, the joints supporting the legs continue to stretch, and the hip muscles exert force to achieve the organic combination of pedal and pendulum. The joint muscles generate hip extension moments in the early stage of support, release energy to do positive work, and push the body forward.

Then the hip flexor group acts to absorb the energy generated by the hip flexor group, preparing to drive the support leg forward into the swing period.

So.

Next stage.

That is, after running on the way?

At this stage, maintaining horizontal ground reaction force is crucial to maintaining speed stability. At this time, athletes need to minimize the loss of horizontal force through efficient technical movements and muscle coordination.

At the same time, the reaction force on the vertical ground must ensure the body's airflow and smooth landing, and the dynamic characteristics of the hip and ankle joints are significantly related to the maximum running speed.

Larger hip extension and flexion torque and dorsal flexion torque of the ankle can produce greater propulsion force, and the increase in hip extension can improve the effect of ground reaction forces by increasing the step length.

Dorsiflexion of the ankle joint helps increase the reaction force of the soles and increase the forward driving force.

According to the relationship between three-dimensional ground reaction force and sprint performance, we can know-

Vertical direction and three-dimensional ground reaction force:

The first is support and vacancy.

Vertical ground reaction force directly affects the athlete's support time and aerial altitude.

Excellent sprinters can generate a large peak of vertical ground reaction force at the moment of touching the ground, which allows them to quickly push their bodies off the ground, shorten the support time, and increase the aerial height and time.

The key point is here!

Get up the small stool!

For every 0.01 second shortening of the support time, the step frequency can be increased by 1-2 steps/minute.

Bolt's support time during his peak period was only 0.08 seconds, which is one of the important factors in achieving the dual advantages of "step frequency + stride".

Of course, with Joyna's humanity at present.

There is still a gap.

But it's already quite terrifying.

Almost few men can catch up.

In the vertical direction, the ground reaction force interacts with gravity. If the athlete can convert the energy generated by the stomping into upward and forward kinetic energy through reasonable technical actions...

When landing, energy loss is reduced through buffering of the lower limb joints and stored elastic potential energy for the next pedal.

Then theoretically, it can...

Appropriate lower limb stiffness can reduce the impact force when touching the ground, reduce the risk of injury, and quickly rebound the foot, using elastic energy stored in muscles and ligaments.

Reduce energy loss.

Improve energy utilization efficiency.

Make running more efficient.

This is the first aspect of optimizing using three-dimensional ground reaction forces.

The second is the relationship between horizontal direction and three-dimensional ground reaction force:

Horizontal ground reaction force is the main driving force for athletes to start and accelerate.

During the starting stage, the strong horizontal pushing force allows athletes to obtain greater acceleration.

Then it's time to run on the way.

Continuous and stable horizontal force helps maintain high-speed running.

Research from Sushen Laboratory shows that the value of the ground reaction force in the horizontal direction and its ratio of the ground reaction force occupying the ground are linearly related to the movement speed, and the power of the horizontal ground reaction force and the movement speed are in a quadratic equation.

What does it mean?

To be simple, it is -

Reduce braking!

When landing, the brake force will be generated because the placement is often in front of the center of gravity.

Athletes need to use reasonable technical movements, such as keeping the knee joint fully bent, positioning close to the center of gravity, etc., to reduce the braking effect and use more energy to advance forward.

For people with faster speeds, especially top athletes, they emphasize the "ground-pulling" technology. They actively stretch their hips when they are not landed before they fall in front of their feet, and produce a "ground-pulling" action to bring the place closer to the center of gravity of the body, effectively reducing the stretching of the calf during traditional running, thereby greatly reducing the braking and braking force. At the same time, forward propulsion is generated in the "ground-pulling" link, combined with the rear pedal, and increase forward momentum.

Braking is reduced.

Can it be faster and smoother.

Is there no upper limit?

Since it is a three-dimensional ground reaction force, there is still one shortcoming.

Front and rear direction.

Although the ground reaction force in the front and back directions is relatively small, it plays a key role in maintaining the body's lateral balance and stability.

During the sprinting process, the athlete's body will be disturbed by various external forces, such as air resistance, curve centrifugal force, etc. By fine-tuning the front and rear directions, the athlete can maintain the straight line of the body on the track to avoid wasting energy or affecting speed due to lateral deviation.

After all three forces are reintegrated.

Su Shen ran on the way.

It also began to show different things.

Bolt thought, OK, Sue, you can.
To be continued...