Youth Baseball Pitch Counts Vastly Underestimate High-Effort Throws Throughout a Season.         

Wahl EP1, Pidgeon TS, Richard MJ. J Pediatr Orthop. 2020 Feb 7. doi: 10.1097/BPO.0000000000001520. [Epub ahead of print]

Take-Home Message

The official pitch count fails to reflect the number of throws by 11- and 12-year-old youth baseball players.


Despite Little League Baseball (LLB) pitch count rules, which require no more than 85 pitches/day for 11- to 12-year olds, shoulder and elbow injuries are becoming more common in youth baseball. The increased risk of injury may be because the pitch count rules fail to account for other throwing activities (e.g., warm-up pitches) and athletes in other positions. Having a more accurate estimate of the number of throws by young baseball players may help improve pitch count rules. Therefore, the authors used wearable sensors to measure how many throws a young baseball player actually threw during a season compared with an official pitch count. The authors provided an elbow sleeve with a sensor to 19 youth baseball players (11- and 12-year olds; 9 pitchers) from one league to wear each time they threw (practice, warm-ups, games) throughout a season. They only wore the sleeve during activities for this one league. The athletes also completed a survey to collect demographics and to answer questions about whether they follow other Pitch smart recommendations. The athletes had good compliance with wearing the elbow sensor (~75%). The sleeve sensor tracked the number of throws, elbow valgus torque, arm speed, workload, arm slot at release, and high-effort throws (> 70% the average of the top 5 throws from the prior 2 weeks). The authors removed elbow sensor data from non-throwing efforts (running bases, batting). The authors also relied on the designated scorekeeper’s official pitch counts from each game. On average during the season, the sensor detected a lot more throws (~1666; range 577 to 3,115) and high-effort throws (~577; range: 90 to 1371) than the official pitch count (~168; range 0 to ~500). Every player had a greater number of high-effort throws than the official pitch count. The players also reported poor compliance with Pitch Smart recommendations: 37% reported playing at least 9 months/year, 84% reported playing for multiple teams, and 42% reported throwing curve-ball type pitches.  


The authors add to the growing body of evidence behind the risk factors for shoulder and elbow injuries among youth baseball players. The authors confirmed a prior study where authors also reported that the official pitch count underestimates the number of throws among pitchers. Based on this new study, young athletes are also throwing significantly more potentially hazardous high-effort throws. Furthermore, they showed that we may need to pay more attention to throws by players in other positions. For example, one player had ~83% of his throws (1651 total throws) defined as high effort; yet, he never pitched in a game. Hence, pitch count limits are necessary, but these rules fail to capture all the throws that could contribute to injury in youth baseball. It should also be noted that many athletes failed to adhere to some of the other Pitch Smart recommendations. Overall, the evidence suggests that pitch count rules need to be modified to account for the various situations when a player may experience high-effort throws. Furthermore, we need to increase the awareness of these guidelines and the risk of injury related to excessive throwing.

Questions for Discussion

Do you think the Little League Baseball should update rules to include warm-up pitches and measuring high effort throws? Have you ever tracked the number of warm-up pitches?

Written by: Jane McDevitt
Reviewed by: Jeffrey Driban

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