Kinetic Arm in NPB: How Japan's Baseball Pros Adopted Dynamic Arm Support

Kinetic Arm's rise in Nippon Professional Baseball (NPB) did not begin with a major sponsorship campaign.

It began with professional baseball players trying the technology.

Pitchers across multiple Japanese organizations began incorporating Kinetic Arm into throwing and training. Players shared it with teammates. National sports media documented its use. And in June 2023, Kinetic Arm reached another important milestone: NPB certification for in-game use.

Among the professional players connected with its early adoption were Shota Imanaga, then an ace for the Yokohama DeNA BayStars, and Atsuki Yuasa of the Hanshin Tigers. In April 2023, major Japanese sports publication Nikkan Sports reported that approximately 15 NPB players were already using Kinetic Arm.

The story provides an unusual look at how a new sports technology can move through elite baseball: player introduction → professional use → player-to-player recommendations → national media coverage → cross-team adoption → league approval for competition.

And at the center of that adoption was a different approach to baseball arm support: supporting the shoulder and elbow together during movement.

Key Takeaways

• Kinetic Arm spread through Japanese professional baseball largely through player use and player-to-player exposure.
• Shota Imanaga was among the prominent NPB pitchers associated with Kinetic Arm before his move to Major League Baseball.
• Atsuki Yuasa's use was independently documented by Nikkan Sports in April 2023.
• Nikkan Sports reported that approximately 15 NPB players were using Kinetic Arm at that time.
• Adoption extended across players connected with multiple NPB organizations.
• In June 2023, Kinetic Arm received NPB certification for in-game use.
• The K2 BioKinetic® Sleeve provides dynamic dual-joint shoulder and elbow support through patented MuscleWeb® technology.
• Kinetic Arm is designed to provide movement-responsive external support—not generate throwing force.
• Subsequent pitching research presented at the 2025 MLB Winter Meetings measured significant reductions in elbow varus torque and shoulder distraction force with Kinetic Arm, while ball velocity was not significantly reduced.
• Kinetic Arm's NPB story is ultimately about professional adoption and in-game acceptance, rather than any single athlete endorsement.

How Did Kinetic Arm Get Into Japanese Professional Baseball?

Kinetic Arm was introduced into Japanese baseball through Hiroshi Takiguchi of Reggie Smith Baseball Japan, helping put the technology in front of professional players and throwing athletes.

From there, adoption became increasingly player-driven.

Pitchers from different NPB organizations began testing Kinetic Arm during throwing and training to determine whether Dynamic Arm Support fit into their routines.

That player-driven introduction is significant because Kinetic Arm represented an unfamiliar approach to arm support.

Rather than focusing exclusively on the elbow or shoulder, the K2 BioKinetic® Sleeve was designed around the relationship between both joints during throwing.

Baseball pitching is a coordinated kinetic-chain movement in which force generated by the lower body and trunk is transferred through the shoulder, elbow, forearm and hand before reaching the baseball.

Kinetic Arm's approach to Dynamic Arm Support reflects that interconnected movement.

→ Learn how Kinetic Arm Dynamic Arm Support works

Shota Imanaga: One of Kinetic Arm's Early High-Profile NPB Users

One of the most recognizable players associated with Kinetic Arm's early adoption in Japan was Shota Imanaga.

Before joining Major League Baseball, Imanaga established himself as one of Japan's leading pitchers with the Yokohama DeNA BayStars.

Across eight NPB seasons from 2016 through 2023, Imanaga compiled a 64-50 record with a 3.18 ERA and 1,021 strikeouts. His career in Japan included two NPB All-Star selections, a 2022 no-hitter and the Central League strikeout title in 2023.

His international profile grew further during the 2023 World Baseball Classic, when he started and earned the win in Japan's championship-game victory over the United States.

Imanaga was also among the professional pitchers incorporating Kinetic Arm into his throwing routine during his NPB career.

He described his experience with the technology this way:

“Using the Kinetic Arm allows you to maintain the correct angle of the arm.” — Shota Imanaga

His involvement also illustrates how Kinetic Arm began moving from one professional player to another.

According to Kinetic Arm's account of its adoption in Japan, Imanaga purchased a Kinetic Arm for Yokohama teammate Yofrec Diaz during Diaz's return-to-throw progression following elbow surgery.

That is an important part of the adoption story.

Rather than simply seeing a product promoted to professional athletes, one player chose to put the technology into the hands of another player.

Shota Imanaga Brings Kinetic Arm to Teammate Yofrec Diaz

Shota Imanaga's experience with Kinetic Arm did not stop with his own throwing routine.

Imanaga believed enough in the technology to purchase a Kinetic Arm K2 BioKinetic® Sleeve for Yokohama DeNA BayStars teammate Yofrec Diaz, who was working through his recovery following Tommy John surgery.

For Diaz, Kinetic Arm became part of his recovery and return-to-throw routine, providing external Dynamic Arm Support as he progressed back into throwing.

That distinction is important. Kinetic Arm does not treat a UCL injury or replace rehabilitation, physical therapy or a medically supervised throwing program. Instead, the K2 BioKinetic® Sleeve is designed to provide movement-responsive external support across both the shoulder and elbow while an athlete performs active arm movements.

For an athlete returning to throwing, that means Dynamic Arm Support can be incorporated alongside the recovery plan established by the athlete's medical and performance team.

The Diaz story is also one of the clearest examples of how Kinetic Arm began spreading through Japanese professional baseball.

This was not a company sending another athlete a promotional product. It was one professional pitcher purchasing Kinetic Arm for a teammate and introducing him to technology he had already incorporated into his own routine.

That kind of player-to-player recommendation helped Kinetic Arm move organically through NPB clubhouses—and soon, evidence of that broader adoption began appearing publicly in Japanese baseball media.

→ Learn how Kinetic Arm supports baseball throwing

Atsuki Yuasa and the Nikkan Sports Moment

Kinetic Arm gained much wider public visibility in April 2023 when Nikkan Sports featured Hanshin Tigers pitcher Atsuki Yuasa using the product during throwing activities.

The coverage is particularly valuable because it provides independent Japanese media documentation of professional use.

In its report, Nikkan Sports described Yuasa using Kinetic Arm during catch play and identified other NPB pitchers who had also incorporated the technology.

The publication reported that roughly 15 NPB players were using Kinetic Arm at the time, including Imanaga and other professional pitchers.

Yuasa told Nikkan Sports that he felt his arm came up more easily while wearing the support and that he intended to continue using it because it allowed him to achieve the arm action he wanted.

That is an important distinction.

Rather than Kinetic Arm making an unsupported performance claim about an athlete, the feedback came directly from a professional pitcher describing his own experience with the product.

Why the Nikkan Sports coverage mattered

The article established several important facts for Japanese baseball audiences:

• Kinetic Arm was already being used by multiple NPB players.
• Adoption extended across different teams.
• Players were evaluating it during real throwing activity.
• Professional athletes were discussing how it felt and how it fit into their throwing routines.
• Dynamic shoulder-and-elbow support was becoming visible in one of the world's highest levels of baseball.

The story provided independent evidence that Kinetic Arm's Japanese adoption was broader than a single player or organization.

From Player Adoption to NPB In-Game Certification

The next milestone came shortly afterward.

In June 2023, Kinetic Arm received certification from Nippon Professional Baseball for in-game use.

Kinetic Arm's NPB certification documents the milestone and explains that the certification allowed Japanese professional players to wear Kinetic Arm during games.

This moved the technology beyond a training-only context.

Players could now integrate Dynamic Arm Support into actual NPB competition in accordance with the league's equipment approval.

That is an important part of the Kinetic Arm story because the K2 BioKinetic® Sleeve is designed specifically for active athletic movement rather than immobilization.

It is intended to support the shoulder and elbow while the athlete continues throwing, swinging, fielding and moving normally.

What NPB certification means—and what it does not mean

NPB approval for in-game use demonstrates that Kinetic Arm was accepted for use as player equipment within Japanese professional baseball.

It should not be interpreted as an NPB medical endorsement or a league guarantee regarding injury outcomes.

The significance is simpler and more relevant:

Professional players in Japan were permitted to wear Kinetic Arm while competing in NPB games

Kinetic Arm Adoption Spread Across NPB Teams

Imanaga, Diaz and Yuasa were not isolated examples.

Kinetic Arm has documented use among professional players associated with multiple NPB organizations, demonstrating how Dynamic Arm Support began moving across Japanese professional baseball rather than remaining within a single clubhouse.

Yasunobu Okugawa — Tokyo Yakult Swallows

Yasunobu Okugawa was another early NPB player associated with Kinetic Arm.

The Tokyo Yakult Swallows pitcher emerged as one of Japan's notable young arms and earned Central League Climax Series MVP honors during the Swallows' 2021 championship run.

His adoption added another organization to Kinetic Arm's growing presence in Japanese professional baseball.

Ippei Ogawa — Hanshin Tigers

Ippei Ogawa added to Kinetic Arm's presence within the Hanshin Tigers organization.

Along with the independently documented use by Atsuki Yuasa, Ogawa's association with Kinetic Arm provides another example of multiple professional pitchers within the same NPB organization incorporating the technology into their routines.

Shunsuke Kasaya — Fukuoka SoftBank Hawks

Shunsuke Kasaya brought Kinetic Arm into another prominent Japanese professional organization: the Fukuoka SoftBank Hawks.

His use further demonstrated that interest in Dynamic Arm Support was extending across different NPB clubs rather than remaining concentrated around the original Yokohama users.

Masaya Kuroda — Saitama Seibu Lions

Masaya Kuroda was among the Saitama Seibu Lions pitchers documented using Kinetic Arm as the technology continued spreading through Japanese professional baseball.

For developing professional pitchers managing substantial throwing workloads, the appeal of Dynamic Arm Support centers on providing movement-responsive external support across the shoulder and elbow without rigidly restricting the throwing motion.

Shinya Sugai — Saitama Seibu Lions

Saitama Seibu Lions pitcher Shinya Sugai also became a visible Kinetic Arm user in Japan.

Sugai described his own experience with the technology in particularly strong terms:

“Kinetic Arm that reduces the stress on the arm by 30% are a must for every pitcher.” — Shinya Sugai

That statement should be understood as Sugai's individual testimonial, not as a universal performance or injury-prevention claim by Kinetic Arm.

His use nevertheless provides another example of a professional pitcher independently incorporating Kinetic Arm into his throwing routine.

Shinya Miyamoto — Japanese Baseball Veteran and Coach

Kinetic Arm's Japanese baseball presence has not been limited to active pitchers.

Shinya Miyamoto, the longtime Yakult Swallows infielder and later coach, has also been associated with Kinetic Arm.

Miyamoto's involvement is particularly interesting because it broadens the story beyond pitching. Position players also accumulate substantial throwing volume across practice, warmups and competition, creating repetitive demands on the shoulder-and-elbow system.

His experience provides a different perspective on Dynamic Arm Support from the pitcher-focused examples that make up much of Kinetic Arm's early NPB adoption story.

What Cross-Team Adoption Tells Us

Taken together, the athletes associated with Kinetic Arm represented several different NPB organizations:

• Yokohama DeNA BayStars: Shota Imanaga and Yofrec Diaz

• Hanshin Tigers: Atsuki Yuasa and Ippei Ogawa

• Tokyo Yakult Swallows: Yasunobu Okugawa; Shinya Miyamoto as a veteran player/coach connection

• Fukuoka SoftBank Hawks: Shunsuke Kasaya

• Saitama Seibu Lions: Masaya Kuroda and Shinya Sugai

That distribution is more meaningful than simply counting individual users.

Kinetic Arm was gaining exposure among athletes working within different organizations, training environments and competitive systems.

Why Dynamic Shoulder and Elbow Support Matters for Pitchers

Traditional arm-support products generally focus on a single area.

An elbow compression sleeve surrounds the elbow and forearm.

A shoulder support focuses on the shoulder.

A rigid brace may intentionally limit joint movement depending on its purpose.

Pitching, however, does not occur at one joint.

Baseball throwing relies on a coordinated kinetic chain in which force is generated and transferred through multiple body segments.

The shoulder positions and accelerates the upper arm.

The elbow experiences substantial mechanical demand as energy moves toward the forearm and hand.

After the baseball is released, the upper extremity must rapidly decelerate the arm.

That interconnected movement is the reason Kinetic Arm is designed around dual-joint support rather than an elbow-only or shoulder-only solution.

→ See why dual-joint arm support matters

How MuscleWeb® Technology Works During Throwing

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.

The system provides passive external mechanical support.

It does not contain motors, electronics, springs or powered components that propel the athlete's arm.

Instead, the architecture changes tension as the arm moves.

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

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

The design spans areas including the:

• anterior shoulder
• posterior shoulder
• upper shoulder
• medial elbow
• lateral elbow
• forearm

This allows Kinetic Arm to provide coordinated external support across the upper extremity while preserving the functional movement required for pitching.

→ Explore patented MuscleWeb® technology

What Research Shows About Kinetic Arm During Pitching

The player experiences from Japan are compelling, but they are not the only evidence available.

Kinetic Arm has also been evaluated through controlled pitching-biomechanics research.

A study titled “The Acute Effects of a Dynamic Stabilizer on Pitching Kinematics and Kinetics in Adult Baseball Pitchers” examined 20 adult pitchers using a randomized crossover design.

Pitchers 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 examine variables including:

• elbow varus torque
• shoulder distraction force
• shoulder internal rotation velocity
• maximum shoulder external rotation
• ball velocity

Researchers measured statistically significant reductions in elbow varus torque and shoulder distraction force while pitchers wore Kinetic Arm.

At the same time, ball velocity was not significantly different between conditions.

That distinction is important.

Kinetic Arm is not designed to add velocity or generate throwing force. It is designed to provide external support while the athlete performs the movement.

Under the study conditions, researchers measured reductions in specific shoulder-and-elbow loading variables without a statistically significant reduction in ball velocity.

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

→ Read the Kinetic Arm MLB Winter Meetings pitching research

→ Explore Kinetic Arm Research & Data

Why Elbow Torque and Shoulder Loading Matter

The measurements used in the Kinetic Arm research are established variables within pitching biomechanics.

During the pitching motion, the shoulder and elbow experience substantial mechanical demands as the arm accelerates and decelerates.

Research indexed by the National Institutes of Health has examined elbow torque and shoulder forces as important biomechanical variables in throwing athletes.

For example, peer-reviewed research on professional and collegiate pitching mechanics has examined how ball velocity relates to elbow valgus torque and shoulder distraction force.

This external research does not evaluate Kinetic Arm.

Instead, it provides independent context for why the variables measured in Kinetic Arm testing matter when researchers study the physical demands of pitching.

Is Kinetic Arm a Throwing Aid?

No. Kinetic Arm does not generate throwing force.

It has no motor, spring, battery or powered mechanism propelling the arm forward.

The athlete creates the throw.

MuscleWeb® provides passive external mechanical support during that movement.

That distinction is especially relevant when discussing in-game use. Dynamic Arm Support is designed to support movement rather than create movement.

The fact that Kinetic Arm subsequently received NPB certification for competition provides a real-world example of a professional baseball league permitting the product as in-game equipment.

Why Japanese Professional Baseball Was an Important Milestone

The adoption of Kinetic Arm in Japan matters for reasons beyond the number of athletes wearing it.

NPB represents one of the highest levels of professional baseball in the world.

Japanese baseball also places enormous emphasis on repetition, skill development and detailed movement preparation.

Kinetic Arm entered that environment as an unfamiliar category of support and gained traction through professional players testing it themselves.

The progression tells the story:

Player introduction → professional use → player-to-player sharing → national media coverage → broader adoption → NPB in-game certification.

That sequence is a powerful example of how a new sports-performance category can gain credibility.

Not through hype.

Through use.

From NPB to MLB: Shota Imanaga's Baseball Journey

Imanaga's career creates another interesting bridge between Japanese and American professional baseball.

After eight seasons with Yokohama, he moved to Major League Baseball with the Chicago Cubs in 2024.

His official MLB biography confirms a Japanese career that included a 64-50 record, 3.18 ERA, two NPB All-Star selections, a no-hitter and 1,021 strikeouts before his move to Chicago.

He also started and earned the win for Japan in the championship game of the 2023 World Baseball Classic.

His subsequent success in MLB brought greater international recognition to a pitcher who had already been associated with Kinetic Arm during his years in Japan.

For Kinetic Arm, Imanaga's story is not evidence that the product caused his success.

It is something simpler and more credible:

An elite professional pitcher independently chose to incorporate Dynamic Arm Support into his arm-care recovery and throwing routine.

Kinetic Arm's Japanese Baseball Story Continues Beyond One Player

That distinction is important because Kinetic Arm's presence in Japan is not an endorsement story built around a single athlete.

It is an adoption story.

Imanaga helped make the technology visible.

Yuasa discussed his experience with it publicly.

Nikkan Sports documented broader use across NPB.

Players from multiple organizations incorporated the technology.

And NPB ultimately certified Kinetic Arm for in-game use.

Together, those events provide a clearer picture of how Dynamic Arm Support moved from an unfamiliar technology into professional baseball competition.

Frequently Asked Questions About Kinetic Arm and NPB

Is Kinetic Arm approved for use in NPB games?

Kinetic Arm received NPB certification for in-game use in June 2023. That certification allows professional baseball players in Japan to wear the product during NPB competition. 

Do Japanese professional baseball players use Kinetic Arm?

Yes. Kinetic Arm has documented use by players across multiple NPB organizations, and independent Japanese media has reported on professional pitchers wearing it. 

Did Shota Imanaga use Kinetic Arm in Japan?

Yes. Imanaga was among the prominent NPB pitchers associated with Kinetic Arm during his Yokohama DeNA BayStars career. He has publicly described how the support influenced his arm positioning during throwing.

Did Atsuki Yuasa use Kinetic Arm?

Yes. Nikkan Sports documented Hanshin Tigers pitcher Atsuki Yuasa using Kinetic Arm during throwing in April 2023 and published his comments about how it felt during his arm action.

What is Dynamic Arm Support?

Dynamic Arm Support is movement-responsive external support designed for active arm movement. Kinetic Arm's K2 BioKinetic® Sleeve provides coordinated support across both the shoulder and elbow through patented MuscleWeb® technology.

How is Kinetic Arm different from a compression sleeve?

Traditional compression garments primarily provide circumferential fabric pressure. Kinetic Arm incorporates a tension-based polymer architecture designed to provide movement-responsive external support across both the shoulder and elbow.

Does Kinetic Arm restrict a pitcher's motion?

Kinetic Arm is designed to preserve functional range of motion rather than rigidly immobilize the shoulder or elbow. In Kinetic Arm pitching research, maximum shoulder external rotation did not significantly change and ball velocity was not significantly reduced under the tested conditions.

What does research show about Kinetic Arm Dynamic Arm Support?

Multiple independent studies and case reports have evaluated Kinetic Arm during throwing and return-to-throw activity. Research has shown measurable reductions in elbow varus torque and shoulder distraction force while preserving ball velocity, along with additional findings related to arm speed, throwing mechanics and workload management. One of the most recent studies, involving 20 adult pitchers, was presented at the 2025 MLB Winter Meetings.

Does Kinetic Arm prevent pitching injuries?

No product can guarantee that a baseball injury will be prevented. Kinetic Arm should instead be understood as proactive Dynamic Arm Support designed to help manage mechanical demands during repetitive movement. Specific research findings should be interpreted as measured biomechanical outcomes, not guarantees of injury prevention.

Is Kinetic Arm only for professional pitchers?

No. Kinetic Arm is used by competitive and recreational baseball players across multiple positions and levels. Pitchers, catchers, infielders and outfielders all perform repetitive throwing actions that place demands on the shoulder-and-elbow system.

Player-Driven Adoption. Research-Backed Dynamic Arm Support.

Kinetic Arm's emergence in Japanese professional baseball offers an unusual case study in sports-technology adoption.

Professional players tried it.

Players shared it with other players.

Japanese sports media documented its use.

Athletes across multiple organizations incorporated it into their throwing routines.

NPB then certified it for use in games.

At the center of that story is a simple biomechanical concept: the shoulder and elbow function together during throwing, so arm support can be designed around both joints rather than treating them in isolation.

That is what Kinetic Arm's patented MuscleWeb® technology is built to do.

And subsequent pitching research has added measurable evidence to the player experiences that first helped Dynamic Arm Support gain traction in Japan.

What began with professional pitchers testing a new kind of arm support became a technology approved for competition in one of the world's premier professional baseball leagues.

→ Shop K2 BioKinetic® Dynamic Arm Support