The Su God of the Reopening of the Sports Arena

Chapter 2450 From now on, this will no longer be your exclusive weapon.
Bend your arm...

It turned out to be...

A bent-arm start?
It's understandable that Su Shen was shocked.

because.

At least for now.

He hasn't passed this method and approach on to anyone yet.

Although he knew that with the help of a reasonable scientific team and long-term analysis, he could gradually figure out the tricks of the trade, the time required to figure them out would not be short.

He believes it's impossible for Bolt to complete this during his active career.

but.

Bolt is now standing right in front of him...

They set up their bent-arm start.

This made Su Shen feel surprised and uncertain for the first time.

Seeing Suarez's expression, Bolt felt a surge of secret satisfaction.

My thoughts immediately drifted back to the past two years.

……

In sprinting, the starting technique, as the initial stage of the entire race, directly determines whether an athlete can convert muscle power into effective forward propulsion within a 0.1-0.3 second reaction window. Its core evaluation indicators include reaction time, push-off reaction force, and forward shift speed. Traditional sprint starting technique is centered on "straight-arm support - rapid push-off." This technique is designed based on the body structure of athletes of average height (1.75-1.85m), expanding the support surface through straight-arm support to ensure stability in the "ready" position.

And you, Usain Bolt, as the most influential sprinter in history, have a height of 1.96m, which far exceeds the average height of sprinters—a body structure that gives him a stride advantage.

At its peak, stride length can reach 2.6-2.8m or more.

This results in a longer torso due to their natural height.

If a straight-arm start is used, the hip joint needs to be excessively bent in the "ready" position to lower the center of gravity, which can easily cause tension in the back muscles. In addition, the coordination between the upper limb force and the lower limb push-off decreases when the straight arm pushes off, resulting in a "delayed force" problem.

This is also why Su Shen believes that even if Bolt knew and figured out the principles, it wouldn't be so easy for him to master.

After all, he made technical modifications for Zhao Haohuan back then.

It took a lot of time.

It's not a direct copy.

Bolt is taller than Zhao Haohuan.

There are even more design steps required.

He didn't think that the other side could do it so quickly.

The core technical challenge for tall athletes lies in balancing "center of gravity height with stability":
For every 10cm increase in height, the center of gravity increases by about 6-8cm when standing. The starting "ready" position requires lowering the center of gravity below the knee joint to ensure the leverage advantage when pushing off the ground.

In traditional straight-arm starts, tall athletes need to adjust their posture in the following ways.

1. Bending the hip joint significantly, reducing the angle between the torso and the ground to below 30°, will overstretch the erector spinae muscles in the lower back, which can easily lead to muscle fatigue.
2. Extending the arm support distance (the support point is about 40-45cm from the body's midline when the arm is straight) causes the force lines of the upper and lower limbs to be not on the same vertical plane, making it easy for "left and right deviation" to occur when pushing off the ground, thus reducing the effective conversion rate of the support reaction force.

This is because the support Bolt was using during his run was not very stable and kept changing.

Mills conducted detailed research on the bent-arm start based on his detailed observations of Sue.

He finally found a way to effectively target Bolt.

That is--

The first point.

This contradiction is resolved by using the articulated start technique to "shorten the support radius and optimize the alignment of the force line".

The elbow flexion angle should be controlled between 90° and 100°, and the support point should be about 25-30cm away from the body's central axis. This ensures that the upper limb support line and the lower limb push-off force line are basically coincident through the line connecting the hip, knee, and ankle joints, thus reducing the dispersion of force.

Second point.

Raise the torso to a 45°-50° angle with the ground without excessively bending the hip joint, reducing tension in the lower back muscles by 20%-30%.

According to electromyography (EMG) monitoring data, the integral EMG value of the erector spinae muscle decreased from 85 μV·s with the arm straight to 65 μV·s.

At the same time, maintain the center of gravity height at 50-55cm, and 45-50cm when the arm is straight, to balance stability and power generation space.

This is because, according to biomechanical modeling results, when Bolt starts with his arms bent, the force distribution across his body's joints is naturally more even:

For example, the force on the hip joint decreased from 2.5 times body weight when the arm is straight to 2.1 times body weight, and the force on the knee joint decreased from 3.0 times body weight to 2.7 times body weight, effectively reducing the risk of joint injury.

This also explains why Bolt suffered fewer lower limb joint injuries during the starting phase throughout his career, unlike other tall sprinters.

He once suffered excessive stress on his knee joint due to a straight-arm start.

Patellar tendinitis has occurred multiple times.

It can affect one's career.

Mills then extended his research on the energy transfer mechanism of the flexed-arm start, based on its adaptability to the body structure of tall athletes.

It is well known that the energy transfer process at the start of a sprint can be divided into three stages: “muscle energy storage - energy release - force transmission”, with the core objective being to activate the lower limb muscle groups.

Quadriceps, hamstrings, gluteus maximus.

The stored elastic potential energy is efficiently converted into forward kinetic energy, and the upper limb movements do not only play a supporting role in this process, but also participate in energy transfer through swinging.

Just as the "ready" position is a key step in muscle energy storage, at which point athletes need to stretch muscle fibers to the "optimal contraction length" through muscle pretension.

That is, the initial muscle length is equal to 1.2 times the resting length.

To activate muscle spindles and Golgi tendon organs.

Increase muscle contraction speed.

In a traditional straight-arm start, the upper limb muscles, such as the triceps and deltoids, are in a state of "overstretching".

When supporting the arm straight, the initial length of the triceps brachii is 1.4 times its resting length, which exceeds the optimal contraction range, resulting in a 15%-20% decrease in its contractile force.

Bolt's height and arm span allow him to start with his elbows bent at 90°-100°. His biceps brachii's initial length is 1.1-1.2 times its resting length, and his triceps brachii's initial length is 1.0-1.1 times, both within his natural optimal contraction range.

Electromyography data showed that the pre-activation level of the upper limb muscle groups was 18% higher than that of the straight-arm start.

This prepares the body for subsequent swinging and force generation.

In addition, the energy storage efficiency of the lower limb muscles is also optimized due to the bent-arm posture.

When Bolt is in the "ready" position with his arms bent, his knees are bent at an angle of 135°-140°, his hamstrings increase in initial length by 5%-8%, and his elastic potential energy storage increases by 12%.

The hip flexion angle is 110°-115°, and the initial length of the gluteus maximus is within the optimal range.

in this way.

It can generate greater force when contracting.

If the above points are achieved, we can assume that the core of Bolt's energy release after the starting gun is "coordinated force exertion of the upper and lower limbs", that is, the time difference between the lower limbs pushing off the ground and the upper limbs swinging needs to be controlled within 0.02 seconds to avoid "disconnection of force exertion".

In traditional straight-arm starts, tall athletes need an extra 0.03-0.05 seconds to push off the ground due to the longer support distance of their upper limbs. This causes the upper limbs to swing later than the lower limbs to push off the ground, resulting in a phenomenon of "lower limbs exerting force first and upper limbs following behind," which reduces energy transfer efficiency.

If it can be done, that's what Mills envisions.

Bolt's energy release during his bent-arm start gives him a "synchronization advantage".

What is the advantage of synchronicity?
Mills can be viewed from three perspectives—

1. At the moment of pushing off the ground, the quadriceps and gluteus maximus muscles of the lower limbs exert force first, generating a vertical supporting reaction force, with a peak value of 3.2 times the body weight. At the same time, the hip joint extends rapidly, propelling the trunk forward;

2. In terms of the upper limbs, the bent-arm posture shortens the lever arm of the arm swing, increases the contraction speed of the biceps and triceps by 25%, and increases the swing frequency from 1.2 times/second when the arm is straight to 1.5 times/second, ensuring that the time difference between the upper limb swing and the lower limb push-off is controlled within 0.01-0.02 seconds, and achieving "simultaneous force exertion of the upper and lower limbs";
3. The moment of inertia of the torso decreases due to the bent-arm posture. According to the formula for moment of inertia, I=mr, the radius of rotation of the upper limb mass decreases from 0.85m when the arm is straight to 0.5m, and the moment of inertia decreases by 60%. This makes it easier for the torso to follow the force of the upper and lower limbs to rotate, further increasing the forward movement speed of the center of gravity.

According to motion capture data, when Bolt starts with his arms bent, the energy loss rate from his lower limbs to his torso is only 8%-10%, while the loss rate for a traditional straight-arm start is 15%-18%.

The efficiency of converting the energy into forward momentum is 12%-15% higher than that of a straight-arm start, which is the core source of its speed advantage in the 30-meter acceleration phase after the start.

In this way, the force transmission path is from the moment of push-off to the moment of first landing after the starting block push-off.

Bolt's body can then enter the "unsupported phase".

At this point, the force transmission path changes from "ground-lower limbs-trunk-upper limbs" to "trunk-upper and lower limbs" coordinated swinging, the core of which is to balance the torque generated by the lower limbs pushing off the ground through the swinging of the upper limbs.

Further avoid body rotation.

As for tall athletes, due to their long torsos, if their upper limbs do not swing sufficiently, they are prone to "torso torsion" problems.

In a traditional straight-arm start, the swing amplitude of the straight arm is relatively small, with a forward and backward swing angle of about 60°. In this case, it is difficult to balance the torque generated by the lower limbs pushing off the ground.

If Bolt had changed to a bent-arm start...

The arm can swing at an angle of 90°-100°.

Furthermore, the swing trajectory is closer to the body's central axis.

It can generate a larger balancing torque.

In this case, according to biomechanical analysis, the balancing torque generated by Bolt's upper limb swing after pushing off the starting blocks could be 15-18 N·m.

It is 1.3 times that of a straight-arm start.

Guess what.

This precisely offsets the 16-17 N·m torque generated by the lower limbs pushing off the ground.

Keep your body moving in a straight line.

Avoid lateral offset.

At the same time, the "whipping effect" of the arm is more pronounced after the arm is bent.

The forearm extends rapidly in the later stages of the swing.

The kinetic energy of the upper limbs is transferred to the trunk.

Further promote the shift of focus forward.

This caused Bolt's center of gravity to be positioned 10-15cm forward when he landed on his first step compared to when he started with his arms straight.

This lays the foundation for further stride length expansion.

such.

Mills believed that this could support the redistribution of the reaction force.

From "decentralized compensation" to "centralized efficiency".

Because the supporting reaction forces during the starting phase, including vertical and horizontal reaction forces, are the core driving forces that propel the body forward.

The rationality of its allocation directly determines the efficiency of force conversion.

In traditional straight-arm starts, tall athletes experience a "dispersed compensation" characteristic in their support reaction force due to their body structure limitations. However, in bent-arm starts, the support reaction force is "concentrated and efficient" by adjusting the position of the support point and the angle of the torso.

Mills had tried many methods before.

I can't figure it out either.

Now, here with Su Shen.

It gave him inspiration!
Since it's a classic straight-arm start.

That's no longer possible.

There's no room for improvement.

So……

What if we switched to a curved start with an Eastern, mystical feel?

after all!

Take a look.

They are not just Su Shen.

That Zhao, who is also over 1.9 meters tall and is known as the "Chinese Usain Bolt".

Can't we use this same startup system?

He believed in Su Shen's presence.

It's impossible to provide Zhao Haohuan, a core member of Ersha Island, with an unsuitable startup system for no reason.

Such mistakes may occur elsewhere.

But on Ersha Island in the far east.

This is unlikely.

At this point.

Mills believed in Sue.

It's more important to believe in yourself.

You still need to believe!
Since they are also tall, over 1.9 meters, they can use it.

Why not? Why can't Bolt do it?
perhaps.

A password that I have always found difficult to crack.

Is it hidden within this new startup system?
Many people don't know this.

Even on the original timeline, Su Shen created the unprecedented 6.29.

But Bolt also has a split time of 6.29 seconds.

Even in 2025, some people researched and found that this version was closer to reality.

It's definitely faster than 6.31 seconds, which everyone has considered to be Bolt's strongest time for over a decade.

It takes about 6.30 seconds.

After all, when calculating segmented data, the non-zero carry-over method is not used.

Rounding is acceptable.

In that case, the actual result could be even higher.

Of course, it doesn't matter which version it is.

Above the thousandths, Su Shen is still faster.

Because there is no version of Su Shen with a time of less than 6.29 seconds.

If you're calculating the thousandths place, rounding will only go up.

博尔特的这个版本即便是修正之后，也就是说在6秒29~6秒30之间。    取6秒30左右，这个值最科学。

after all.

The measurement method and frame rate are different at this time.

It's not as accurate and stable as it would be in 10 years.

So if we really have to calculate it...

Su Shen's data is still faster.

But even so.

You also need to figure out the biggest gap in their future prospects before this...

It's about the startup process.

Besides.

There is nothing that Su Shen will lose to in terms of future prospects.

So how do we crack Bolt's startup password?
This has become a crucial issue.

If we can break through this point.

Even if there isn't much improvement in other areas.

Bolt could easily improve.

Of course, Boulder is already unique in this regard.

Someone who can run that fast.

At his height.

It is already the only one with such unique advantages.

Over the years, Mills has never given up on researching the flexed-arm start.

Perhaps during the 2006 FIFA U-20 World Cup in Beijing.

When he saw Su Shen use it.

It's already eye-catching enough.

Make him remember it deeply.

It has been almost 10 years now.

He finally succeeded after studying day and night.

With your own talent.

We found some breakthroughs.

To achieve a redistribution of the supporting force for tall athletes, the focus needs to shift from "distributed compensation" to "concentrated and efficient"...

It is necessary.

Optimization of vertical support reaction force.

This reduces joint load and improves power generation efficiency.

Because vertical support reaction force is the key to counteracting the body's weight and generating upward support force, its peak value and duration directly affect the effect of pushing off the ground.

In traditional straight-arm starts, there are two major problems with the vertical support reaction force of tall athletes.

First, the peak load is delayed; second, the joint load is uneven.

Usain Bolt certainly exists as well.

The Track and Field Sacred Body can minimize these negative buffs.

But to say there is absolutely none.

That's nonsense.

Mills did the test—

In terms of peak time, tall athletes need 0.03-0.05 seconds to push off the ground with their straight arms before they can initiate the lower limb push-off.

This directly results in the peak of the vertical support reaction force occurring 0.04-0.06 seconds later than that of athletes of average height.

Theoretically, when Bolt starts with his arms bent...

The elbow joint should be bent at 90°-100°.

The support point is about 25-30cm from the body's midline, and 40-45cm when the arm is straight. This changes the upper limb support from "actively pushing away" to "passively transitioning".

No extra time is needed to complete the straight-arm push-off movement; the movement can be initiated directly by pushing off the ground with the lower limbs.

That's it.

The peak time of the vertical support reaction force is advanced to 0.08-0.10 seconds.

It's roughly the same height as athletes of average height.

For someone of Bolt's height, being equal to him means overcoming physical and physiological limitations.

It is already a huge success.

Because he can still pull off such a start even with the reduced power; if he were to maintain the same level, what would happen?!
Not to mention, from the perspective of joint load, when starting with straight arms, the distribution of vertical support reaction force in the lower limb joints will show the characteristic of "excessive load on the knee joint".

Even for Bolt, due to excessive forward lean of the torso and hip flexion angle ≤90°, the vertical reaction force is distributed in the knee joint at a ratio of 55%-60%.

Only 45%-50% of athletes are of average height.

The peak force on the knee joint reaches more than 3.0 times the body weight, far exceeding the safety threshold. And if Bolt were to start with his arms bent...

The angle between the torso and the ground can be increased to 45°-50°.

The hip flexion angle can be increased to 110°-115°.

垂直支撑反力在下肢关节的分配比例就可以调整为：髋关节35%-40%、膝关节40%-45%、踝关节15%-20%。

In this case.

In theory.

Bolt reduced the peak force on his knee joint to 2.5 times his body weight, while the force on his hip joint decreased from 2.5 times his body weight to 2.1 times his body weight, thus achieving a balanced distribution of joint load.

Not to mention, Mills conducted tests in a rudimentary sports biology lab in Jamaica—

Biomechanical modeling results show...

If Bolt can start with a bent arm, the "effective time" of the vertical support reaction force.

That is, the duration during which the reaction force is greater than 1.5 times the body weight.

This can extend the time from 0.12 seconds with a straight arm to 0.15 seconds.

Extended by 25%.

It provides a longer window for the lower limb muscles to exert force.

The impulse during push-off increases from 320 N·s with straight arm to 380 N·s!

An increase of 18.75%!

This directly propels the speed from approximately 0.7 m/s to about 3 meters after the start!

In addition, the horizontal support reaction force is optimized.

Shorten the lever arm to improve horizontal propulsion efficiency.

The horizontal support reaction force is the core driving force propelling the body forward, and its magnitude is inversely proportional to the horizontal lever arm, the horizontal distance from the point of support to the center of gravity. In traditional straight-arm starts, tall athletes often have an excessively long horizontal lever arm, resulting in insufficient horizontal support reaction force.

The bent-arm start shortens the horizontal lever arm.

This makes it relatively easy to increase the horizontal support reaction force.

For example, when starting with a straight arm, the upper limb support point of a tall athlete is far from the body's central axis, which will result in a horizontal lever arm, with the horizontal distance from the support point to the center of gravity reaching 0.35-0.40m.

According to the principle of torque balance, in order to maintain body stability, the horizontal support reaction force needs to be controlled at a low level; otherwise, it is easy to cause excessive forward leaning of the body. Once Bolt starts running with his arms bent, the support point will shorten to 25-30cm from the body's central axis.

The horizontal lever arm is reduced to 0.20-0.25m.

The horizontal support reaction force can be increased to 1.5-1.8 times the body weight.

Increase by 25%-50%.

In this way, by considering the direction of the horizontal support reaction force, we can avoid the problem of the horizontal reaction force easily "shifting outward" when starting with a straight arm because the horizontal distance between the support point and the center of gravity is too long.

This results in a decrease in the effective propulsive force and the component of the horizontal reaction force in the forward direction.

The starting technique can be different if you bend your arm to start.

Take this approach.

The support point is closer to the body's central axis.

Therefore, the angle between the horizontal reaction force and the direction of forward movement is ≤5°.

This increases the effective propulsion ratio from 85%-90% with a straight boom to 95%-98%.

The efficiency of implementation has been significantly improved.

Motion capture data shows that if Bolt starts with his arms bent, the impulse of his horizontal support reaction force will increase from 180 N·s when his arms are straight to 240 N·s.

An increase of 33.33%.

This directly propels the horizontal acceleration at the 3-meter mark after the start to continue to break through and improve.

And these.

The problem had been troubling him for a long time, and he had always been just one step away from success.

The theoretical breakthrough was ultimately achieved by studying Zhao Haohuan, rather than Su Shen.

Suddenly, progress was made.

This made him suddenly realize something.

Instead of racking your brains to study this Su Shen who is only a little over 1.8 meters tall.

It would be better to focus all your attention on Zhao Haohuan, who is about the same height as Bolt.

such.

After changing our perspective, we indeed found a breakthrough.

In addition, there has been nearly 10 years of accumulation.

We have finally overcome the difficulties posed by these two principles.

This allows Bolt to at least use a half-bend arm configuration.

Or it could be a pseudo-curved arm mode.

The gun is fired and the race begins.

But what truly completed this evolution was...

Apart from Mills' side.

Another aspect is the collaboration with American laboratories.

Numerous data systems and data models have been developed with higher precision.

In an instant, he solved several problems that Mills couldn't solve.

This.

This is why Bolt is striking this pose now.

Even Yang Jian.

Watch.

Their expressions suddenly changed drastically.

He spoke as if he had seen a ghost:
"Yosem".

“Usain Bolt…he seems to be…”

"Bent arm start???"

Not loud.

He was almost like a pebble thrown into the center of a lake.

It instantly resonated deeply within the domestic track and field community.

Ersha Island serves as a symbolic representation of benchmark technology.

There was even a time when some people claimed that only people of Asian descent could master this kind of starting line.

Bend your arm and stand up.

It appeared out of nowhere for the first time.

On a person who is not yellow-skinned and has black hair.

For the first time in history.

Appear.

And this guy.

It was none other than Black Lightning, known as the Holy Body of Track and Field.

Jamaican.

Usain Bolt.

"Su."

"This weapon is no longer your exclusive weapon."

"I."

"I can do that too."