When 75 elite Dominican baseball prospects—average age just 17.9 years—underwent full shoulder and elbow imaging for a Major League Baseball scouting event, the results revealed something few expected: nearly every pitcher, and most position players, showed significant structural changes. None of them reported symptoms.

At first glance, the data reads like a list of chronic injuries—partial UCL tears, labral fraying, rotator cuff tendinosis, and olecranon osteophytes. But these athletes were considered healthy. This raises an uncomfortable but vital question for player development: at what point does adaptation become pathology, and when does youth exposure to high workloads cross from developmental to degenerative?

What the Study Found

Researchers from Columbia and the New York Yankees medical staff examined 75 Dominican MLB prospects, including 33 pitchers and 42 position players. All players received shoulder and elbow radiographs, while pitchers underwent additional MRI imaging. Despite being asymptomatic, the majority displayed imaging abnormalities more typical of professional veterans.

In pitchers:

• Rotator cuff pathology was present in 93.9%, including 78.8% with tendinosis and 15.2% with partial tears.
  
  
• Labral tears appeared in 75.8%.
  
  
• UCL abnormalities were detected in 81.8%, with 24.2% partial tears and 6.1% complete ruptures.
  
  
• Olecranon osteophytes, indicators of posteromedial impingement, appeared in 69.7%.
  
  

In position players:

• Abnormal elbow imaging was actually more common than in pitchers (81% vs. 57.6%; P = .03).
  
  
• Common findings included olecranon osteophytes (23.8%), medial epicondyle nonunions (11.9%), and signs of Little Leaguer’s shoulder (14.3%).
  
  

The scale of these findings was unprecedented in such a young, asymptomatic group—suggesting that exposure, intensity, and year-round specialization have accelerated musculoskeletal adaptation to levels rarely seen outside professional baseball.

Why This Matters

From a physiological standpoint, the imaging results don’t necessarily equal injury. In fact, many of these findings—like rotator cuff hypertrophy, bony adaptation at the olecranon, and mild UCL thickening—can represent sport-specific remodeling. Throwing athletes across all levels demonstrate similar adaptations as protective mechanisms against repetitive valgus and torsional stress.

However, the timeline is what stands out. Comparable studies on U.S.-based high school or collegiate pitchers report similar imaging findings—but typically in players several years older, and with greater accumulated throwing volume. The Dominican prospects reached this level of adaptation by age 17.9, well before physical maturity or fully ossified growth plates.

That discrepancy points toward an imbalance between exposure and recovery. In development systems where throwing is both livelihood and identity, the absence of structured recovery periods likely accelerates these changes. Without consistent off-seasons, periodized workloads, or professional-level medical oversight, these adaptations occur earlier, potentially at the cost of long-term joint health.

Interpreting Adaptation vs. Pathology

This study underscores a critical nuance often missed in discussions about youth injury risk: imaging tells us structure, not function.

• A thickened UCL may indicate resilience just as easily as degeneration.
  
  
• A labral tear might coexist with full, pain-free range of motion and stability.
  
  
• Even osteophyte formation can serve as a stress-distributing adaptation to chronic valgus load.
  
  

The problem arises when the rate of adaptation outpaces the body’s ability to recover. Pathology, in this context, may not stem from a single injury event but from accumulated micro-failures that begin before professional exposure ever arrives. The Dominican cohort illustrates how structural changes can outpace systemic readiness—both physically and organizationally.

What This Reveals About the Development Model

Baseball in the Dominican Republic has long been both a cultural cornerstone and a professional pipeline. By age 16, many top prospects train full time in private academies, throwing and hitting daily, year-round. Signing bonuses depend on performance metrics—velocity, spin, arm strength—that reward short-term output rather than long-term sustainability.

The results of this study provide a stark physiological reflection of that environment. These athletes are not injured, but they are aged by workload. Their bodies exhibit the same compensatory patterns and tissue wear found in professionals a decade older.

This doesn’t indict Dominican development—it exposes the biological cost of unregulated exposure, a pattern that is increasingly mirrored in the U.S. travel ball circuit. Early specialization compresses years of mechanical stress into condensed developmental windows, leaving little room for regeneration or tissue remodeling.

How We Apply This at VeloU

At Velo University, we interpret data like this through the lens of readiness, not restriction. The goal isn’t to prevent adaptation—it’s to manage its rate. Structural change is inevitable in elite throwers, but the progression should parallel physical maturity, not outpace it.

That’s why our development model emphasizes:

1. Monitored workloads using wearable metrics for torque, pitch count, and recovery cycles.
   
   
2. Movement literacy phases that train kinetic chain efficiency before maximal output.
   
   
3. Rotational balance and eccentric control, particularly across the shoulder and forearm flexor-pronator complex.
   
   
4. Planned exposure periods, ensuring year-round play doesn’t become year-round load.
   
   

The lesson from the Dominican cohort isn’t that high workloads always harm—it’s that unstructured workloads reshape the body faster than we can measure their consequences. The data validates a principle we’ve seen across hundreds of athletes: high-velocity training is safest when progression is earned, not accumulated through constant play.

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The Fortney study shines a light on the biological reality of global baseball development. Even in the absence of pain, the scans tell a clear story—one of adaptation, overexposure, and the urgent need for structured recovery in youth training systems. These findings challenge the assumption that “healthy” means “normal.”

Structural change is not inherently bad. But if the elbow and shoulder of a 17-year-old already resemble that of a 30-year-old professional, the system must ask: what will these arms look like by 25?

The future of sustainable player development lies in understanding that longevity isn’t about throwing less—it’s about throwing intelligently.

References

Fortney, T. A., Luzzi, A. J., Tenner, Z. M., Ma, K., Rogalski, B. L., & Ahmad, C. S. (2025). The Prevalence of Shoulder and Elbow Pathology in Major League Baseball Prospects From the Dominican Republic. Sports Health, 17(4), 766–774. https://doi.org/10.1177/19417381241277790