Here's a question worth asking: does throwing harder always mean more joint stress? The obvious answer seems like yes, but the data tells a more complicated story. A 2020 study from the International Society of Biomechanics in Sport Conference analyzed 273 pitches from college and high school pitchers and found something interesting. Overall, velocity showed positive linear relationships with both shoulder distraction force and elbow valgus torque. But when they isolated only pitches above 85 mph, those relationships disappeared. No correlation between velocity and joint stress at high velocities. Except that's not the full picture either, because when they separated the groups by level, college pitchers above 85 mph showed no relationship between velocity and stress, while high school pitchers at the same velocities maintained a significant positive relationship.

So what's actually happening here? Are we looking at a survival effect where only the most efficient pitchers make it to college? Are we seeing the impact of physical maturity and frame size on force dissipation? Or is this just what happens when you slice data into smaller and smaller subgroups until the sample size can't support the conclusions you're trying to draw? Probably all three.

Researchers used 3D motion capture with a 40-marker setup and a sixteen-camera system to track 70 baseball pitchers (23 college, 47 high school) throwing fastballs at regulation distance. Ball velocity was recorded with Trackman, and motion data was collected at 250 Hz. They normalized shoulder distraction force by body weight and elbow valgus torque by body weight times height, then used multivariable linear regressions with fractional polynomial regressions to investigate relationships. The goal was to determine whether pitching velocity correlates with shoulder and elbow loading, and whether those correlations differ between competition levels.

What The Study Found

A total of 273 pitches were included in the analysis. Of these, 101 pitches were thrown above 85 mph by 28 pitchers (20 college, 8 high school). College pitchers had greater height, weight, pitch velocity, elbow valgus torque, and shoulder distraction force compared to high school pitchers. These differences were significant even after normalizing for body size, which tells you that the raw structural advantages aren't fully explaining the performance gap.

When looking at the entire sample, there was a positive linear relationship between pitch velocity and shoulder distraction force (r² = 0.21) and between pitch velocity and elbow valgus torque (r² = 0.32). So across all pitchers and all velocities, throwing harder was associated with greater joint loading. When separated by level, both college and high school pitches exhibited positive linear relationships between velocity and both shoulder distraction force (college: r² = 0.09, high school: r² = 0.32) and elbow valgus torque (college: r² = 0.16, high school: r² = 0.32).

But here's where it gets interesting. In pitches thrown above 85 mph, there was no relationship between pitch velocity and shoulder distraction force (r² = 0.005), nor between pitch velocity and elbow valgus torque (r² = 0.002). Neither college nor high school pitches thrown above 85 mph showed a relationship between velocity and shoulder distraction force. College pitches thrown above 85 mph also did not exhibit a relationship between pitch velocity and elbow valgus torque (r² = 0.007). However, high school pitches thrown above 85 mph exhibited a positive linear relationship between pitch velocity and elbow valgus torque (r² = 0.27).

So what does that mean? When elite high school pitchers push velocity into the 85+ mph range, they're still experiencing proportional increases in elbow stress. But when college pitchers operate at those same velocities, the relationship between velocity and torque disappears. They're generating force without proportionally increasing joint loading.

The authors noted that despite normalizing for body weight and height, high school pitchers throwing above 85 mph exhibited greater normalized shoulder distraction forces and elbow valgus torques compared to college pitchers throwing at similar velocities. That's a red flag. It suggests decreased pitching efficiency in high school athletes who are pushing into velocity ranges their bodies may not be ready to handle.

Why This Information Matters

To be honest, this reminds me of a 2018 study published in The Orthopedic Journal of Sports Medicine that examined rotational kinematics in professional versus high school pitchers. That study analyzed 37 high school and 40 professional pitchers throwing maximal-effort fastballs in a motion capture lab. The findings were remarkably similar to this one. Professional pitchers threw harder but had similar or lower normalized elbow torque compared to high school pitchers. In high school pitchers, velocity was strongly linked to higher elbow torque, but this relationship was absent in professionals. When normalized for body size, high school pitchers actually experienced greater torque at maximum external rotation than professionals. Their arms were paying a higher price for the same or even lower velocity.

The explanation comes down to coordination and sequencing. Professional pitchers used greater trunk and pelvis rotation to generate velocity, effectively offloading stress from the arm. High school pitchers, lacking those refined movement patterns, relied more heavily on arm speed to produce velocity. That difference explains why their velocity tied so tightly to higher torque, while pros could throw harder without increasing stress. The arm becomes the primary force generator when the kinetic chain breaks down, and that's exactly when joint stress spikes.

But physical maturity also plays a role here, and we can't ignore that. A 2025 study in The Orthopedic Journal of Sports Medicine examined how modifiable physical measures influence the elbow varus torque and ball velocity relationship in 87 NCAA Division I pitchers. They found that every 2.2 mph increase in velocity raised elbow torque by about 1.8 Newton-meters. But strength and mobility altered how much torque pitchers experienced for a given velocity. Stronger dominant-shoulder internal rotation strength lowered elbow valgus torque. Greater dominant-shoulder flexion range of motion lowered elbow valgus torque. Physical qualities like shoulder strength, mobility, and trunk control can alter how efficiently energy is transferred through the kinetic chain, changing how much load ultimately reaches the elbow. Velo will always increase stress to some degree, but not equally across all athletes.

The implication is that elbow stress isn't simply a byproduct of velocity. The whole kinetic chain shapes it. Athletes who develop targeted strength and mobility can shift the torque-velocity relationship in a way that sustains velocity while reducing elbow risk. For high school pitchers pushing into high velocity ranges, this matters. If your body isn't physically prepared to support those forces, you're going to experience disproportionate joint loading compared to more mature athletes operating at the same velocities.

And let's talk about body size, because it's relevant here too. A 2025 study in The Journal of Strength and Conditioning Research analyzed 49 youth baseball players (average age 11) and found that height and weight together explained 64.1% of the variance in batted ball velocity. Until stature starts to even out at higher levels, body size will always be one of the most influential factors in youth performance outcomes. The predictive value of body size at younger ages speaks to how much physical development drives performance capacity before movement efficiency and coordination take over. For high school pitchers, especially those on the younger or smaller end of the spectrum, chasing velocity before their frames can handle it creates a mismatch between output and capacity.

There's also research showing that body weight, forearm length, and upper arm length accounted for 38% of the variance in elbow torque among a large cohort of pitchers. Added body mass correlates with added joint stress, but it also correlates with the ability to dissipate and manage that stress. College pitchers aren't just more skilled, they're also physically larger. Their frames provide structural advantages that allow them to handle forces more effectively than smaller, less mature athletes. The normalization by body weight and height in this study helps control for that, but it doesn't fully eliminate the advantage that comes from having a more developed musculoskeletal system.

So when we see high school pitchers at 85+ mph experiencing continued increases in torque while college pitchers at the same velocities don't, we're seeing the combined effect of movement efficiency, physical maturity, strength capacity, and structural development. The college pitchers who made it to that level either learned to generate velocity efficiently or had the physical tools to manage the load. The ones who couldn't do either probably got hurt or didn't advance.

How You Can Apply This Information

The practical takeaway here isn't complicated, but it does require patience. If you're working with high school athletes, especially younger or physically less mature ones, chasing velocity before they're ready creates disproportionate joint stress. The data in this study shows that high school pitchers throwing above 85 mph still experience increases in elbow torque as velocity climbs, while college pitchers at the same velocities don't. That's not just about skill. It's about physical readiness.

Development should prioritize building the physical capacity to handle velocity before pushing athletes into high-output ranges. That means focusing on strength, mobility, and movement efficiency in the early and middle stages of development, not just chasing radar gun numbers. Shoulder internal rotation strength, shoulder flexion range of motion, trunk stability, and hip mobility all contribute to how efficiently force moves through the kinetic chain. Addressing those qualities early gives athletes leverage to manage joint stress as velocity increases.

For athletes already throwing at high velocities, the goal should be refining movement patterns to reduce reliance on the arm as the primary force generator. That means emphasizing trunk and pelvis rotation, improving timing and sequencing, and ensuring the lower body contributes effectively to velocity production. If an athlete is generating high velocity but doing it inefficiently, they're absorbing unnecessary joint stress that could be offloaded through better coordination.

This doesn't mean high school pitchers shouldn't throw hard. It means they need to earn the right to throw hard by building the physical and mechanical foundations to do it safely. And if an athlete is pushing into elite velocity ranges (85+ mph) at a young age, they need to be monitored closely. Regular assessments of joint loading, range of motion, strength symmetry, and movement quality can help identify when stress is accumulating faster than the body can adapt.

Coaches also need to recognize that velocity development isn't linear and doesn't happen on the same timeline for everyone. Some athletes develop early and can handle high velocities at younger ages without issue. Others need more time to build the physical capacity to support those outputs. Forcing the latter group into velocity ranges they're not ready for because that's what the recruiting landscape demands is a recipe for breakdown.

And let's address the limitations of this study, because they matter. The r² value for high school pitchers above 85 mph was 0.27, meaning velocity explained only 27% of the variance in elbow torque. That's not nothing, but it's also not everything. The sample size for this subgroup was only 20 pitches from 8 athletes, so we're drawing conclusions from very limited data. The study used lab norms instead of published literature norms because their shoulder distraction forces came back higher than expected, which raises questions about whether their measurement methods align with other research. They only analyzed fastballs in a single testing session, so we're not accounting for fatigue, breaking balls, or in-season conditions. Kinetic calculations are based on estimated body-segment masses from cadavers, and there's unavoidable skin movement with surface markers.

Most importantly, they didn't account for arm strength, range of motion, timing, or mechanical differences between groups beyond what the motion capture system could detect. Those are all factors that influence how efficiently an athlete generates velocity and how much stress their joints experience in the process. Without controlling for those variables, we can't fully isolate the effect of competition level on the velocity-torque relationship.

But even with those limitations, the trend is consistent with other research. High school pitchers who push velocity without the physical maturity or movement efficiency to support it experience greater joint stress than more developed athletes at the same velocities. That's a pattern worth paying attention to, even if the exact numbers in this study should be interpreted cautiously.

The Bottom Line

Throwing hard increases elbow and shoulder stress, except when it doesn't. The relationship between velocity and joint loading isn't universal. It depends on movement efficiency, physical maturity, strength capacity, and how well the kinetic chain transfers force. College pitchers who can generate high velocity without proportionally increasing joint stress have either developed the coordination to do it efficiently or the physical tools to manage the load. High school pitchers at the same velocities often haven't reached that point yet, which is why they continue to see increases in torque as velocity climbs.

The "survival effect" explanation is speculative without longitudinal data tracking athletes from high school through college, but it makes sense. Pitchers who couldn't increase velocity without increasing stress either got hurt or didn't advance. Those who made it learned to move efficiently or had the structural advantages to handle the forces involved. We also need to account for the larger frames of college pitchers and how that contributes to force dissipation, even after normalizing for body weight and height.

For youth development, the lesson is clear. Slow the process of discovering high velocity until athletes achieve certain physical and mechanical thresholds. Build strength, mobility, and coordination first. Refine movement patterns to reduce reliance on the arm as the primary force generator. Monitor athletes closely when they start pushing into elite velocity ranges. And recognize that not everyone develops on the same timeline. Forcing athletes into velocity ranges they're not ready for creates disproportionate joint stress that mature athletes with refined movement patterns and developed frames can better manage.

Velocity matters in baseball. But how you get there matters just as much. And if the cost of getting there early is absorbing joint stress that your body can't handle, you're not setting yourself up for long-term success. You're setting yourself up for breakdown.

References

1. Nicholson K, Hulburt T, Beck E, Waterman B, Bullock G. The Relationship Between Pitch Velocity and Shoulder Distraction Force and Elbow Valgus Torque in Collegiate and High School Pitchers. 38th International Society of Biomechanics in Sport Conference. 2020.
2. Luera MJ, Dowling B, Magrini MA, Muddle TWD, Colquhoun RJ, Jenkins NDM. Role of Rotational Kinematics in Minimizing Elbow Varus Torques for Professional Versus High School Pitchers. The Orthopedic Journal of Sports Medicine. 2018.
3. Barrack AJ, Sakurai M, Wee CP, Diaz PR, Stocklin C, Karduna AR, Michener LA. Investigating the Influence of Modifiable Physical Measures on the Elbow Varus Torque – Ball Velocity Relationship in Collegiate Baseball Pitchers. The Orthopedic Journal of Sports Medicine. 2025.
4. Bordelon NM, Agee TW, Wasserberger KW, Downs-Talmage JL, Everhart KM, Oliver GD. Field-Testing Measures Related to Youth Baseball Hitting Performance. The Journal of Strength and Conditioning Research. 2025.