Shohei Ohtani and Kinetic Arm: What We Know About the Technology

When Shohei Ohtani appeared with distinctive arm support during the 2024 World Series, baseball fans quickly began asking the same question:

Was Ohtani wearing Kinetic Arm?

There is good reason for the connection.

Kinetic Arm has received information from multiple sources indicating that Ohtani has used the technology, and the company knows that a Kinetic Arm was provided to him. However, because that information has not been publicly confirmed by Ohtani or his representatives, Kinetic Arm does not present his use as an official endorsement.

That distinction is important.

In a January 2025 ClutchPoints feature, ClutchPoints writer Matt Wadleigh took a closer look at the connection between Shohei Ohtani and Kinetic Arm, speaking directly with Kinetic Arm founder Jason Colleran about how the technology reached Ohtani's circle. Colleran confirmed that a Kinetic Arm had been sent to Ohtani and explained that Ohtani's coach, Petie Montero, had already been using Kinetic Arm while throwing batting practice.

So while Kinetic Arm is not claiming an Ohtani endorsement, the story provides a fascinating look at how Dynamic Arm Support is finding its way into high-level baseball—and why athletes, coaches and performance professionals are increasingly interested in supporting the shoulder and elbow together during throwing.

The Ohtani connection may be what brings people to the story. The more important story is the technology, biomechanics and research behind it.

Key Takeaways

• Kinetic Arm has received multiple reports indicating that Shohei Ohtani has used the technology, but Ohtani and his representatives have not publicly confirmed that use.

• Kinetic Arm founder Jason Colleran confirmed to ClutchPoints that a Kinetic Arm was sent to Ohtani.

• Ohtani's coach, Petie Montero, was also reported to be using Kinetic Arm while throwing batting practice.

• Kinetic Arm does not characterize Ohtani as a sponsored athlete, spokesperson or official endorser.

• The K2 BioKinetic® Sleeve is the world's first dynamic dual-joint arm stabilizer, supporting the shoulder and elbow together during movement.

• Its patented MuscleWeb® technology provides movement-responsive external support without motors, electronics or powered assistance.

• Research evaluating Kinetic Arm in 20 adult pitchers found significant reductions in elbow varus torque and shoulder distraction force, with no statistically significant reduction in ball velocity.

• That research was presented at the 2025 MLB Winter Meetings, bringing Dynamic Arm Support research directly into the professional-baseball biomechanics conversation.

• The larger story is not simply who wears Kinetic Arm. It is whether Dynamic Arm Support can measurably change the mechanical demands placed on the throwing arm while preserving natural performance.

Has Shohei Ohtani Used Kinetic Arm?

Kinetic Arm has received multiple reports indicating that Ohtani has used the K2 Sleeve, but Ohtani and his representatives have not publicly confirmed that use or endorsed the product.

What can be stated publicly is that a Kinetic Arm was provided to Ohtani and that the technology was already being used within his training circle.

In the ClutchPoints report, Colleran confirmed that the company knew a Kinetic Arm had been sent to Ohtani. He also discussed the technology's connection with Ohtani's coach, Petie Montero.

For Kinetic Arm, the distinction between reported use and an official endorsement matters. The company does not characterize Ohtani as a sponsored athlete, spokesperson or official endorser. But that leads to a more useful question for baseball players, parents, coaches and performance professionals:

Why would Dynamic Arm Support attract attention around one of the most closely managed throwing arms in professional baseball?

The answer starts with biomechanics.

What Is Kinetic Arm?

Kinetic Arm is the creator of the K2 BioKinetic® Sleeve, the world's first dynamic dual-joint arm stabilizer.

Unlike a traditional compression sleeve that relies primarily on fabric pressure, Kinetic Arm is engineered to provide movement-responsive external support across both the shoulder and elbow while preserving functional range of motion.

That distinction is particularly relevant to baseball because throwing is neither an elbow-only nor a shoulder-only movement.

The baseball pitching motion depends on a coordinated kinetic chain. Force generated through the lower body and trunk is transferred through the shoulder, elbow, forearm and hand before reaching the baseball.

The shoulder positions and rapidly rotates the upper arm. The elbow experiences substantial loading as energy travels toward the hand. After ball release, the upper extremity must then decelerate the arm.

Kinetic Arm's Dynamic Arm Support architecture was developed around this interconnected relationship rather than treating the shoulder and elbow as isolated structures.

→ See how Kinetic Arm Dynamic Arm Support works

Why Shoulder and Elbow Stress Matters in Baseball Pitching

A pitch takes only a fraction of a second, but the throwing arm passes through several mechanically demanding phases.

During late cocking, the shoulder reaches substantial external rotation.

During acceleration, the shoulder rapidly rotates internally while the elbow extends and energy transfers toward the ball.

Following release, the arm must decelerate that rotational energy.

Two measurements frequently used in pitching-biomechanics research help quantify those demands:

• Elbow varus torque, which reflects the internal torque generated to counter the valgus loading occurring at the elbow.

• Shoulder distraction force, which represents tensile loading experienced at the shoulder during the throwing motion.

These are established variables within baseball biomechanics—not measurements created specifically to evaluate Kinetic Arm.

Peer-reviewed research involving high school and collegiate pitchers has found relationships between pitch velocity and both shoulder distraction force and elbow valgus torque. Research published in the Journal of Shoulder and Elbow Surgery examined these relationships across 70 pitchers.

Research involving professional pitchers has likewise documented substantial shoulder distraction forces during pitching and investigated how throwing mechanics influence those forces. Review the professional pitching biomechanics study on PubMed.

This independent literature provides important context for understanding why elbow torque and shoulder distraction force are meaningful measurements when evaluating throwing-arm demands.

Why Supporting Only One Joint Tells Only Part of the Story

The shoulder and elbow do not operate independently during a throw.

The shoulder positions and accelerates the upper arm. The elbow participates in the transfer of energy toward the hand. The forearm and hand complete the sequence through ball release.

After release, the interconnected upper extremity continues working to decelerate the arm. 

That is one reason traditional single-joint products and Dynamic Arm Support should not be treated as interchangeable categories.

A conventional elbow compression sleeve primarily surrounds part of the arm and elbow. A shoulder support focuses primarily on the shoulder.

A rigid brace may be specifically designed to restrict or control motion depending on its intended use.

Kinetic Arm takes a different approach by providing coordinated shoulder and elbow support through one integrated system.

→ Learn why dual-joint shoulder and elbow support matters

What Makes Dynamic Arm Support Different?

Kinetic Arm created the Dynamic Arm Support category around a different question:

Can an external support system reinforce the throwing arm during movement without rigidly restricting how an athlete moves?

The K2 BioKinetic® Sleeve is non-rigid and non-powered. It does not contain motors, electronics or powered components that propel the arm.

Instead, it provides passive external mechanical support that responds to movement.

This distinction can be summarized simply:

More support than a sleeve. More mobility than a brace.

For baseball players, the objective is not to artificially create a throwing motion. It is to support the athlete's existing arm movement across both the shoulder and elbow.

How MuscleWeb® Technology Works

At the center of the K2 BioKinetic® Sleeve is patented MuscleWeb® technology.

MuscleWeb® is a tension-based support architecture that integrates strategically positioned polymer support bands into a flexible textile base.

Rather than providing the same support regardless of arm position, the architecture responds as the athlete moves.

During lower-demand positions, the system remains comparatively passive.

As the shoulder and elbow move into more mechanically demanding ranges, tension increases within the support architecture, providing additional external reinforcement.

The objective is not to power the throwing motion.

Instead, MuscleWeb® is designed to work with the athlete's movement, supporting the shoulder-and-elbow system while preserving functional range of motion.

Its support architecture spans key areas of the throwing arm, including:

• anterior shoulder

• posterior shoulder

• upper shoulder

• medial elbow

• lateral elbow

• forearm

That distribution is intentional. Throwing stress does not occur at one isolated location, and the arm does not function as a collection of independent parts.

What Kinetic Arm Research Presented at the MLB Winter Meetings Shows

This is where the Kinetic Arm story moves beyond reported athlete use and into measurable biomechanics.

Research titled “The Acute Effects of a Dynamic Stabilizer on Pitching Kinematics and Kinetics in Adult Baseball Pitchers” evaluated Kinetic Arm during full-effort baseball pitching.

The study was subsequently selected for presentation at the 2025 MLB Winter Meetings, placing research on Dynamic Arm Support directly into the professional-baseball biomechanics conversation.

The randomized crossover study evaluated 20 adult pitchers. Each athlete threw full-effort fastballs from a regulation Major League Baseball mound both with and without Kinetic Arm.

Researchers used a 10-camera markerless three-dimensional motion-capture system to evaluate pitching mechanics and kinetics.

Variables included:

• elbow varus torque

• shoulder distraction force

• peak arm rotational velocity

• maximum shoulder external rotation

• ball velocity

What Did the MLB Winter Meetings Research Find?

Researchers found statistically significant reductions in:

• elbow varus torque

• shoulder distraction force

• peak arm rotational velocity

Maximum shoulder external rotation did not demonstrate a statistically significant change.

Importantly, ball velocity was not significantly different between the Kinetic Arm and natural-arm conditions.

That last result is particularly relevant when considering Dynamic Arm Support for competitive baseball.

Kinetic Arm is not intended to generate force or make a pitcher throw harder. The athlete still creates the movement and produces the throw.

Instead, the study examined whether providing external Dynamic Arm Support could alter specific mechanical demands experienced by the throwing arm.

Under the conditions tested, researchers measured significant reductions in elbow varus torque and shoulder distraction force without a statistically significant reduction in ball velocity.

→ Read the Kinetic Arm MLB Winter Meetings pitching biomechanics research

Why the MLB Winter Meetings Research Matters

The importance of this research is not simply where it was presented.

It is what was measured.

Independent baseball-biomechanics research has long examined elbow torque and shoulder distraction force as important kinetic variables during pitching.

A study of 67 NCAA Division I pitchers, for example, evaluated the relationship between ball velocity, elbow valgus torque and shoulder distraction force. Read the collegiate pitching kinetics research.

Another study analyzing professional pitchers with three-dimensional motion capture found strong within-pitcher relationships between ball velocity and multiple shoulder-and-elbow kinetic variables, including elbow varus torque and shoulder distraction force. Review the professional pitching research on PubMed.

These external studies did not evaluate Kinetic Arm.

Their value here is different: they demonstrate that the kinetic measurements examined in the Kinetic Arm study are established variables within the broader scientific study of pitching mechanics.

The Kinetic Arm research then asks a product-specific question:

What happens to those measured variables when pitchers throw while wearing a dynamic dual-joint arm stabilizer?

The results provide measurable evidence supporting the concept behind Dynamic Arm Support.

→ Explore the complete Kinetic Arm Research & Data library

Why Professional Baseball Is Paying Attention to Arm-Support Technology

Baseball has become increasingly sophisticated in the way it measures throwing.

Professional, collegiate and advanced developmental programs can evaluate:

• pitch velocity

• throwing volume

• arm speed

• joint kinetics

• joint angles

• workload progression

• movement sequencing

• recovery between throwing sessions

Motion-capture laboratories can quantify forces that were once impossible to see.

High-speed cameras can examine mechanics frame by frame.

Wearable technologies can help quantify workloads.

But measurement and mechanical support are different things.

A motion-capture system can identify mechanical demand. It does not support the arm during the throw.

Dynamic Arm Support approaches the problem from another direction: providing movement-responsive external support while the athlete is moving.

That helps explain why Kinetic Arm is generating interest within baseball—and why the Shohei Ohtani connection attracted attention so quickly.

The Ohtani Connection Is Part of a Larger Baseball Story

The public Ohtani connection is significant, but it is not the only professional-baseball connection discussed in the original ClutchPoints report.

The article also described Kinetic Arm's presence around other professional baseball players and personnel and discussed public use by Chicago Cubs pitcher Shota Imanaga.

That broader context matters.

The lasting Kinetic Arm story is not dependent on proving that one superstar wore a particular product on a particular day.

The more important questions are:

• How does the technology work?

• What happens biomechanically when pitchers use it?

• Can those effects be measured objectively?

• Can the shoulder and elbow be supported together without rigidly restricting natural throwing motion?

• Does that support require sacrificing ball velocity?

Those questions can be studied independently of any celebrity association.

And increasingly, there is research available to answer them.

Kinetic Arm's Presence in Japanese Professional Baseball Goes Beyond Ohtani

The connection between Kinetic Arm and Japanese professional baseball extends beyond the reported use surrounding Shohei Ohtani.

Kinetic Arm has been worn by players in Nippon Professional Baseball (NPB), including athletes who have used the Dynamic Arm Support system during professional training and competition. Kinetic Arm has also received NPB approval for in-game use, demonstrating that the technology has been evaluated for use within Japan's top professional baseball league.

That history adds useful context to the Ohtani story.

Kinetic Arm was already present within Japanese professional baseball before the public speculation surrounding Ohtani, and the technology has been seen on other NPB athletes in competitive baseball environments.

This matters because the product is not simply being discussed as a training-room concept. Its lightweight, non-rigid design is intended for use during active baseball movement, including throwing, fielding and other high-demand arm actions.

→ See how Japanese professional baseball players have used Kinetic Arm

Is Kinetic Arm a Throwing Aid?

No. Kinetic Arm is not designed to generate throwing force.

There are no motors, electronics or powered components propelling the athlete's arm.

The athlete generates the movement.

MuscleWeb® provides passive external mechanical support through tension created as the arm moves.

That distinction matters when discussing both biomechanics and competitive use.

Dynamic Arm Support reinforces the athlete's existing movement rather than generating the movement for them.

Questions about equipment rules are separate from questions about biomechanics, and the applicable rules can vary by governing body and level of play.

→ Read: Is Kinetic Arm Legal in Baseball? What the Rules Actually Say

Who Can Use Dynamic Arm Support in Baseball?

Although pitching creates some of baseball's most recognizable arm demands, repetitive throwing is not limited to pitchers.

Pitchers

Bullpens, warm-ups, throwing programs and competitive innings create repeated high-intensity throwing exposure.

Catchers

Catchers accumulate throws throughout practices and games while also managing the physical demands of receiving.

Infielders

Shortstops, third basemen and middle infielders frequently throw at high intensity from changing arm slots, foot positions and body angles.

Outfielders

Long throws require substantial force production followed by rapid arm deceleration.

Two-Way Players

Players who pitch while also playing another position can accumulate throwing and swinging workloads across multiple roles.

The common denominator is not position.

It is repetitive or high-demand arm movement.

→ Explore Kinetic Arm Dynamic Arm Support for baseball players

What the Shohei Ohtani Story Really Tells Us

The most interesting part of the Shohei Ohtani and Kinetic Arm story is not whether a single image can conclusively identify what he was wearing.

It is what the connection says about the changing conversation around baseball arm support.

Players, coaches and performance professionals increasingly have access to technologies capable of measuring what happens to the shoulder and elbow during a throw.

That creates an obvious next question:

Can anything provide support during the movement itself?

Kinetic Arm was built around that problem.

The K2 BioKinetic® Sleeve provides dynamic, dual-joint shoulder and elbow support through patented MuscleWeb® technology while preserving functional movement.

More importantly, the concept can now be evaluated through objective biomechanics research.

The mechanism can be examined.

The research can be read.

The variables can be measured.

The Ohtani connection may be what introduces a baseball fan to Kinetic Arm.

The science is what explains why Dynamic Arm Support matters.

Frequently Asked Questions About Shohei Ohtani and Kinetic Arm

Has Shohei Ohtani used Kinetic Arm?

Kinetic Arm has received information from multiple sources indicating that Shohei Ohtani has used the technology, and the company knows a Kinetic Arm was provided to him. However, Ohtani and his representatives have not publicly confirmed his use. Kinetic Arm therefore does not characterize Ohtani as a sponsored athlete, spokesperson or official endorser.

Was a Kinetic Arm sent to Shohei Ohtani?

Yes. Kinetic Arm founder Jason Colleran publicly confirmed in his ClutchPoints interview that the company knew a Kinetic Arm had been sent to Ohtani.

Does Shohei Ohtani endorse Kinetic Arm?

No official endorsement has been announced. Kinetic Arm does not represent Ohtani as a sponsored athlete, spokesperson or official endorser.

Why was Kinetic Arm connected to Shohei Ohtani?

The public connection gained attention after viewers noticed distinctive arm support around Ohtani during the 2024 World Series. ClutchPoints subsequently investigated the connection and interviewed Kinetic Arm founder Jason Colleran about the technology that had been provided to Ohtani.

What is Kinetic Arm?

Kinetic Arm is the creator of the K2 BioKinetic® Sleeve, the world's first dynamic dual-joint arm stabilizer. It uses patented MuscleWeb® technology to provide movement-responsive external support across both the shoulder and elbow while preserving functional range of motion.

Is Kinetic Arm a compression sleeve?

No. Although the K2 is worn on the arm, its support mechanism goes beyond fabric compression. MuscleWeb® uses an integrated polymer support architecture that responds to arm movement to provide dynamic support across the shoulder and elbow.

What Kinetic Arm research was presented at the MLB Winter Meetings?

Research titled “The Acute Effects of a Dynamic Stabilizer on Pitching Kinematics and Kinetics in Adult Baseball Pitchers” was presented at the 2025 MLB Winter Meetings. The study evaluated 20 adult pitchers throwing with and without Kinetic Arm using markerless 3D motion capture. Researchers found significant reductions in elbow varus torque and shoulder distraction force, while ball velocity was not significantly different between conditions.

Does Kinetic Arm reduce elbow torque during pitching?

In the adult pitching study presented at the 2025 MLB Winter Meetings, researchers measured a statistically significant reduction in elbow varus torque while pitchers wore Kinetic Arm. That finding describes the acute biomechanical effect measured under the study conditions; it should not be interpreted as evidence that the product prevents a specific injury.

Does Kinetic Arm restrict pitching motion?

Kinetic Arm is designed to provide external support without rigidly restricting functional movement. In the MLB Winter Meetings research, maximum shoulder external rotation did not show a statistically significant change between conditions, and ball velocity was not significantly reduced.

Does Kinetic Arm make pitchers throw harder?

No. Kinetic Arm is not designed as a velocity-enhancement or force-generating device. The athlete generates the throwing motion. MuscleWeb® provides passive external mechanical support as the arm moves.

Why does Kinetic Arm support both the shoulder and elbow?

The shoulder and elbow function as interconnected components of the baseball throwing chain. Both experience significant mechanical demands during pitching. Kinetic Arm's dual-joint design is intended to support those areas together rather than treating each joint as an isolated structure.

Is Kinetic Arm only for pitchers?

No. Pitchers, catchers, infielders, outfielders and two-way players all perform repetitive throwing movements. Kinetic Arm is designed to provide Dynamic Arm Support during repetitive and high-demand arm activity rather than for only one baseball position.

The Bigger Story: Baseball Arm Support Is Changing

The Shohei Ohtani connection has brought significant attention to Kinetic Arm.

But the technology should ultimately be evaluated on something more substantial than a television image—or even the reported use of one extraordinary athlete.

Mechanism. Research. Movement.

Kinetic Arm created the Dynamic Arm Support category around the idea that the shoulder and elbow should be supported as one interconnected system during high-demand movement.

Its patented MuscleWeb® technology provides movement-responsive external support designed to help manage dynamic arm stress while preserving functional movement.

And research presented at the 2025 MLB Winter Meetings has now measured significant reductions in elbow varus torque and shoulder distraction force during full-effort pitching, without a statistically significant reduction in ball velocity.

For baseball players asking what Kinetic Arm actually is, that evidence is ultimately more useful than any celebrity association.

The Ohtani story may introduce athletes to Kinetic Arm. The biomechanics explain why the technology matters.

→ Explore Kinetic Arm for Baseball

→ See How Dynamic Arm Support Works

→ Explore Kinetic Arm Research & Data

 

Original Reporting: This article expands on reporting by Matt Wadleigh for ClutchPoints, including his interview with Kinetic Arm founder Jason Colleran about the connection between Shohei Ohtani and Kinetic Arm.