Hi, I am Mitchell Rentschler, a third-year medical student at the Arizona College of Osteopathic Medicine, Midwestern University, and I am excited to present our research titled Decreased Upper Extremity Season-Ending Injuries Following the Initiation of a Pitch Clock Amongst Major League Baseball Pitchers. In the 2022 Major League Baseball season, a pitch clock was instituted to establish a quicker pace of play. Since then, however, the faster rate of play raised concerns about an increasing amount of season-ending injuries in pitchers. Injury risk associations have been investigated by many other professional sports including the National Basketball Association and the National Football League. Studies of the NBA found that injury risk increased as the minutes played per game increased, particularly later in the season, while studies of the NFL found that risk of injuries increases with previous injuries, age, years of playing, and lack of regular season success. However, both basketball and football are time-limited sports and there are few studies investigating increased rate of play in sports that are not limited by time constraints like in baseball with the MLB. Our objective was to determine if the institution of a pitch clock increased the number of upper extremity season-ending injuries seen in MLB pitchers between the 2022 and 2023 seasons. Our design was a retrospective cohort study of all MLB pitchers from the 2022 and 2023 seasons utilizing publicly available data. The Pro Sport Transaction Database was used to determine player injury, including player movement to and from the injured list, dates and description of player injuries, and player position. In addition, Baseball Savant was used to identify player demographics and pitch-specific metrics including height, weight, BMI, age at the start of season, number of innings pitched, pitches thrown per game, and pitch velocity and acceleration in the X, Y, and Z dimension. The study criteria included a definition of season-ending injuries, which were injuries that resulted in the inability for a player to return to play at least 10 games before the end of the regular season. The inclusion criteria were upper extremity season-ending injuries and players who primary position were listed as pitcher. And the exclusion criteria were injuries sustained after the 153rd game. All data abstracted for the study was completed by research assistants trained by the primary investigator. Training was completed by the primary investigator abstracting individual data with each research assistant to ensure compliance with the protocol and accuracy of data collection. Any disagreements were completed by the primary investigator. Individuals with incomplete or missing data were removed from the final analysis. Abstractor monitoring and data verification was completed by the primary investigator and a total of 10% of all data was reviewed and found to have a Kappa greater than 0.90. Statistical analysis was completed using a t-test and a chi-square to analyze continuous and categorical variables respectively. Then a simple linear regression was used to determine variables that were predictive of season-ending injuries. The results showed that season-ending injuries significantly decreased following the institution of a pitch clock. The only difference between pre- and post-pitch clock pitcher demographics and pitch metrics was the release extension. In addition, the pitch vertical and horizontal movement pattern between 2022 pitchers shown in blue and 2023 pitchers shown in yellow overlaps for all pitch types. The analyzed pitches were included fastballs, FF for forcing fastball, and SI for sinker, breaking balls, SL for slider, and CU for curveball, and off-speed balls, CH for change-up and FS for splitter. In conclusion, the institution of a pitch clock appears to have decreased the number of upper extremity season-ending injuries in MLB pitchers between the 2022 and 2023 seasons. The conclusion is supported by all player demographics and pitch-specific metrics were matched between the 2022 and 2023 season except for pitch release extension. Further investigation of season-ending injury predictors revealed that the 2022 season-ending injuries were associated with pitch release speed and pitch velocity and acceleration in the Y and Z dimension, while 2023 season-ending injury associated predicting factors was pitcher height and average release extension. The faster rate of play following the pitch clock institution could have allowed pitchers to keep their arm warm and loose due to less time between pitches and innings, however the true cause is likely multifactorial. Faster investigations by including a larger sample size and analysis of pitching dynamics could help delineate a true relationship. Thank you for listening and I am happy to answer any questions.

MLB pitchers

pitch clock

injury reduction

retrospective cohort study

pitch metrics