CLINICIAN’S CORNER

Hot Topics in Baseball: Weighted Balls and Pitch Counts

By: Quinn McAnaney, PT, DPT, SCS, CSCS Physical Therapist at PTSMC Guilford

If there is one thing that matters most to developing baseball pitchers, it’s velocity. Whether it’s advancing up levels in travel ball, high school, or the college recruitment trail, these numbers can dictate a lot. Over the last 5-10 years, the topic of weighted baseballs has taken over as a way to increase throwing velocity. The concept is simple: train with a heavier baseball to then perform with more speed with a standard baseball. Some of major league baseball’s best pitchers continue to advocate for its e ectiveness in the o season and as part of a warmup during the regular season. With so many young eyes on social media and the never-ending need for a competitive edge, youth baseball continues to see an uptick in the utilization of weighted baseballs. But at what risk?

Mike Reinold, a leader in the eld of sports medicine, recently conducted a study in 2020 examining the performance bene ts and injury risks associated with weighted baseball training programs in high school baseball players. Over a six-week period, the study demonstrated a 3.3% increase in pitching velocity and a 24% injury rate in the weighted baseball group. Additionally, 67% of the control group demonstrated an increase in pitching velocity just based on the weight training program that both groups were performing throughout the study. Lastly, there was a signi cant increase in shoulder external rotation ROM between 3-8 degrees depending on the weight of the ball in the weighted ball group. Reinold believes that this acute gain in “layback” or ER ROM is the reason for the increase in velocity and injury rates found in this study.

I think the results of this study are fascinating. As a sports resident in South Carolina in 2019, I was fortunate to treat an abundance of little league, high school, college, and professional baseball players and I cannot tell you how many times this topic was brought up by parents and athletes in the clinic. Because weighed baseballs are so well utilized among the professional ranks, naturally it will trickle down to youth sports. However, we need to consider the impact that the extra stress of weighed balls is placing on elbows and shoulders at such a young age. If injury rates were this high in the high school population, I cannot imagine the stats among little leaguers. In general, we need to proceed with caution in athletes who have incomplete growth plate closure, poor throwing mechanics, and underdeveloped musculoskeletal systems. As clinicians, we can utilize this study to better educate patients and parents about the risks associated with this tool and feel a bit more comfortable with its use in the college and professional setting if performed using a structured program.

On the subject of youth baseball, I also wanted to also bring up the topic of pitch counts. One of the biggest predictors of injury in youth baseball is overuse. While many coaches follow appropriate pitch count guidelines, there are still many conversations I have with parents about their kids pitching on back to back days in tournaments and not getting adequate rest. As clinicians, we can improve strength/ROM, throwing mechanics, force development and kinetic chain usage, but all of that falls apart with elevated pitch counts. Major league baseball and USA baseball have put together age appropriate pitch count charts that outline recommended pitches and rest days for coaches to better protect these athletes. I highly recommend having a copy in your clinic to provide parents and athletes to better control this variable and help reduce injury risk.

Bibliography:

Reinold MM, Macrina LC, Fleisig GS, Drogosz M, Andrews JR. Acute E ects of Weighted Baseball Throwing Programs on Shoulder Range of Motion. Sports Health. 2020 Sep/Oct;12(5):488-494. doi: 10.1177/1941738120925728. Epub 2020 Jun 29. PMID: 32598234; PMCID: PMC7485027.

Pitch Smart Guidlines URL: https://www.mlb.com/pitch-smart/pitching-guidelines