Major League Baseball Pitchers Research Articles

Estimating Agent Skill in Continuous Action Domains

Actions in most real-world continuous domains cannot be executed exactly. An agent’s performance in these domains is influenced by two critical factors: the ability to select effective actions (decision-making skill), and how precisely it can execute those selected actions (execution skill). This article addresses the problem of estimating the execution and decision-making skill of an agent, given observations. Several execution skill estimation methods are presented, each of which utilize different information from the observations and make assumptions about the agent’s decision-making ability. A final novel method forgoes these assumptions about decision-making and instead estimates the execution and decision-making skills simultaneously under a single Bayesian framework. Experimental results in several domains evaluate the estimation accuracy of the estimators, especially focusing on how robust they are as agents and their decision-making methods are varied. These results demonstrate that reasoning about both types of skill together significantly improves the robustness and accuracy of execution skill estimation. A case study is presented using the proposed methods to estimate the skill of Major League Baseball pitchers, demonstrating how these methods can be applied to real-world data sources.

Changing It Up: Determining the Nash Equilibria for Major League Baseball Pitchers

In order to prevent batters from hitting a pitch, pitchers must decide on a strategic balance of many different pitch types. While each pitcher has preferred pitches (likely those with which he is most confident), he cannot over-utilize his dominant pitches, or batters will be able to gain a strategic advantage in trying to put the ball into play. We analyze Major League Baseball (MLB) pitch data from 2008 to 2018 in order to determine whether or not MLB pitchers are able to reach the theorized mixed-strategy Nash equilibrium given the pitcher’s skill in utilizing each type of pitch. Our data suggests that MLB pitchers are in fact rational, and succeed in reaching the mixed-strategy Nash Equilibrium.

Performance-Based Outcomes after Revision Ulnar Collateral Ligament Surgery in Professional Pitchers.

To compare performance in baseball pitchers before and after revision ulnar collateral ligament (UCL) surgery using performance metrics. Case series. Public online database. Players who underwent revision UCL surgery between 2015 and 2021 were identified. Players were included if they were Minor League (MiLB) or Major League (Major League baseball [MLB]) pitchers. Players were excluded if they were not pitchers, if they underwent their revision surgery as an amateur, or if there is no record of their primary reconstruction surgery. Revision UCL surgery (repair or reconstruction). Return to sport (RTS) rate, RTS time, pitch velocity, and pitch spin rate. Sixty-five pitchers underwent revision UCL surgery. MiLB pitchers had a shorter RTS time after their primary surgery (15.62 vs 20.77 months, P < 0.01) compared with MLB pitchers but similar RTS times after their revision reconstruction (19.64 vs 18.48 months, P = 0.44). There was also no difference in return to play (RTP) rate overall after primary versus revision reconstruction (P = 1.00). Major League baseball pitchers also had decreased RTS time after primary compared with revision reconstruction (15.62 vs 19.64 months, P < 0.01) but similar RTP rates (P = 0.28). Finally, MLB pitchers had similar pitch breakdowns, velocities, and spin rates before and after their primary and revision repair or reconstruction. Both revision UCL repair and reconstruction can return pitchers to preinjury performance levels. Pitchers and teams should be properly counseled on realistic RTP times and postsurgery performance when discussing revision UCL surgeries.

Is Workload Associated With Internal Impingement in Professional Baseball Pitchers? An Analysis of Days of Rest, Innings Pitched, and Batters Faced.

Internal impingement is a common cause of shoulder pain and dysfunction in baseball pitchers. The purpose of this study was to determine if the amount of rest days between outings, the number of innings pitched in each outing, and the number of batters faced in each outing are risk factors for internal impingement in professional baseball pitchers. It was hypothesized that a higher workload would significantly increase a pitcher's risk of developing internal impingement. Case-control study; Level of evidence, 3. All professional (Major and Minor League) baseball pitchers who were diagnosed with internal impingement between 2011 and 2017 were identified using the Major League Baseball's Health and Injury Tracking System. A separate player usage data set was used to determine workload. The authors compared workload variables (days of rest, innings pitched, and batters faced per game) between each of 4 injury-exposure groups (pitchers with documented internal impingement <2, <6, <12, and >12 weeks after a game) and a control group of pitchers with no internal impingement using Student t tests or Mann-Whitney U tests. In a within-pitcher paired analysis of the injury groups, the workload variables during 3 acute periods (<2, <6, and <12 weeks preinjury) were compared with the baseline values (>12 weeks preinjury). Overall, there were 624 professional baseball pitchers diagnosed with internal impingement during the study period. Compared with pitcher games (n = 213,964), pitchers in all 4 injury-exposure groups had significantly more innings pitched per game (P ≤ .003 for all) and faced significantly more batters per game (P < .001 for all). There were significantly more starting pitchers in each of the injury-exposure groups when compared with the controls (P < .001 for all). However, when comparing acute and baseline workloads in the pitchers diagnosed with internal impingement, there were no significant differences in the number of innings pitched, batters faced, or days of rest. This analysis revealed significantly greater pitcher workload and percentage of starting pitchers in professional baseball players diagnosed with internal impingement when compared with healthy controls. However, this injury did not seem to be associated with an acute increase in workload.

Comparison of the "Tall and Fall" Versus "Drop and Drive" Pitching Styles: Analysis of Major League Baseball Pitchers During a Single Season.

Previous research has documented the proportion of "tall and fall" (TF) and "drop and drive" (DD) pitching styles among Major League Baseball (MLB) pitchers who underwent ulnar collateral ligament reconstruction (UCLR). The proportion of these 2 styles among all MLB pitchers remains unknown. To determine the proportion of the TF and DD pitching styles in all rostered MLB pitchers during a single season as well as the proportion of TF and DD pitchers who sustained an upper extremity (UE) injury and those who underwent UCLR. Cross-sectional study; Level of evidence, 3. Pitcher demographic characteristics from the 2019 MLB season and pitching information were obtained via open-access sources. Two-dimensional video analysis was used to categorize the included pitchers into TF and DD groups. Statistical comparisons and contrasts were made using 2-tailed t tests, chi-square tests, and Pearson correlation analyses as appropriate. Of the 660 MLB rostered pitchers in 2019 (age, 27.39 ± 3.51 years; body mass index, 26.34 ± 2.47 kg/m2; fastball velocity, 150.49 ± 3.99 kph [93.51 ± 2.48 mph]), 412 (62.4%) pitchers used the TF style and 248 (37.6%) pitchers used the DD style. Significantly more UE injuries were seen in the TF group compared with the DD group (112 vs 38 injuries, respectively; P < .001). Twelve pitchers underwent UCLR (TF, 10; DD, 2), representing a 1.8% UCLR rate among all pitchers. This was a second surgery for 2 pitchers, both of whom used the TF pitching style. Significantly more pitchers in the TF group than the DD group had undergone UCLR before 2019 (135 vs 56 pitchers, respectively; P = .005). The results of the present study demonstrated a higher prevalence of both UE injury and prior UCLR in TF pitchers. Further research is needed to explore the potential association between pitching style and UE injury.

Hidden Pitches in Major League Baseball: What Are the Injury Implications of These Often Overlooked Pitches?

Pitch counts are tightly monitored in Major League Baseball (MLB). Hidden pitches-including warm-up pitches before and between innings and pitches before the starting/relieving pitcher's appearance in a game-are not as closely monitored. To report the number of hidden pitches thrown per game and over the course of a season for a single organization. We hypothesized that players who threw more hidden pitches would be at an increased risk of injury compared with those who threw fewer hidden pitches. Case-control study; Level of evidence, 3. All pitchers who played for a single MLB organization in the 2021 season were included. Hidden pitches, in-game pitches, and total pitches thrown during all games in the season were recorded. Injuries to these pitchers were also recorded. Players were defined as having an injury if they spent any time on the injured list. Overall, 137 pitchers were included, 66 (48%) of whom sustained an injury and were placed on the IL during the 2021 season (mean time on IL, 53.6 ± 45.6 days). Of the 66 players who sustained an injury, 18 (27.3%) sustained an elbow injury, while 12 (18.2%) sustained a shoulder injury. Only 1 player sustained an ulnar collateral ligament tear. When comparing hidden pitches, in-game pitches, and total pitches between pitchers who sustained an injury and those who did not, there were no significant differences between groups (P = .150; P = .830; and P = .377, respectively). On average, hidden pitches made up 45.4% of the total number of pitches thrown during the course of the season. When evaluating the number of hidden pitches as a percentage of the total number of pitches thrown in a season, there was no significant difference between pitchers who sustained an injury and those who did not (P = .654). MLB pitchers who sustained an injury did not throw more hidden pitches than those who did not sustain an injury. Larger scale studies are needed to confirm the results of this single-team study.

Return to Play After Shoulder Arthroscopy in Major League Baseball Pitchers vs Position Players

Recovery from shoulder arthroscopy may vary between professional pitchers and position players in Major League Baseball (MLB). The time that it takes to return to play (RTP) and the level of skills to be regained after surgery are important factors for an athlete to consider when making career decisions. To identify MLB players who had arthroscopic shoulder surgery and observe their rates of RTP to MLB and the minor league, as well as to compare pre- and postinjury performance statistics and career metrics. Descriptive epidemiology study. Public records (press releases, http://www.prosportstransactions.com, http://www.baseball-reference.com) were searched and analyzed to determine the number of days from shoulder arthroscopy to RTP and pre- and postinjury statistics for pitchers and position players in the MLB and minor league from 1998 to 2018. To meet inclusion criteria, a player must have undergone shoulder arthroscopy after having played at least 1 game in the MLB and had no identifiable concomitant injuries. Of 134 players, 89 (66.4%) returned to MLB. Fifty-four of 89 pitchers (60.7%) and 35 of 45 position players (77.8%) returned to MLB (P = .048). Forty-nine of 54 pitchers (90.7%) and 23 of 35 position players (65.7%) who returned to MLB returned to the minor league first. The mean time to RTP was 469.6 days (range, 100-1079 days) for pitchers and 301.6 days (range, 94-1488) for position players (P = .002). The WAR statistic (wins above replacement) for the pitchers decreased significantly (P = .004) after shoulder arthroscopy. MLB position players returned to play at higher rates and more quickly than did pitchers. The WAR statistic declined in pitchers during the first season of RTP. Players undergoing arthroscopic shoulder surgery should be aware of these possible outcomes in time to RTP and postoperative performance.

Is fantasy baseball score a viable outcome measure for professional baseball pitchers after undergoing Tommy John surgery?

Although on-field performance metrics are useful in measuring overall success of ulnar collateral ligament (UCL) reconstruction (UCLR) in professional baseball pitchers, they may not comprehensively quantify athletic performance after returning to playing in the league. To utilize fantasy baseball score (FBS) as a novel and objective outcome to assess the quality of return to play in major league baseball (MLB) pitchers who went back to professional pitching after UCLR. This is a retrospective observational cohort study of 216 established MLB pitchers who underwent UCLR while in the MLB between the years 1974 and 2018. Pitchers who either started in at least 45 games or pitched 90 relief games in the 3 years leading up to injury were included. FBS was calculated using 3 different scoring methods: ESPN (Entertainment and Sports Programming Network) (FBS-ESPN), Yahoo (FBS-Yahoo), and CBS (Columbia Broadcasting System) (FBS-CBS). Return to play, games played, innings pitched, earned runs, strikeouts, walks, hits allowed, hit batsman, and quality starts were also collected. Performance records were compiled for 3 years prior to and after the return to MLB. Players' pre-injury performance was used as a historic control group. Multivariate linear regression analysis was used to detect trends between seasons, controlling for year of surgery, and number of games. The mean age of the cohort at the time of surgery was 30.0±3.5 years. One hundred seventy-nine of 216 players (83%) returned to MLB play, taking an average of 16.6±5.8 months. One hundred thirty-six of 179 (76%) remained in the league for 3 seasons. After adjusting for year of surgery, pitchers earned significantly fewer points for FBS-CBS (616.45±332.42 vs. 389.12±341.06; P<.001), FBS-Yahoo (801.90±416.88 vs. 492.57±428.40; P<.001), and FBS-ESPN (552.76±275.77 vs. 344.19±300.45; P<.001) after their injury. Also pitchers played in fewer games, pitched fewer innings, and had a decline in all measured on-field performance statistics. FBS may represent a useful outcome measure to objectively assess the quality of return to play in a professional baseball pitcher who returned to play in MLB after UCLR.

Retrospective Analysis of Ulnar Collateral Ligament Reconstructions in Major League Baseball Pitchers: A Comparison of the "Tall and Fall" Versus "Drop and Drive" Pitching Styles.

Background:Previous pilot research has investigated differences in elbow valgus torque between the “tall and fall” (TF) and “drop and drive” (DD) pitching styles. Whether one of these pitching styles is associated with a greater rate of ulnar collateral ligament reconstruction (UCLR) is currently unknown.Purpose:To determine the proportion of Major League Baseball (MLB) pitchers using the TF and DD pitching styles who underwent UCLR over a 10-year period.Study Design:Cross-sectional study; Level of evidence, 3.Methods:The demographic characteristics of pitchers who underwent UCLR between 2007 and 2017 were obtained via the open-source database MLB Player Analysis Tommy John Surgery List. Other information, such as previous UCLR and pitching videos and graphics, was obtained from other open-source databases. A comprehensive, 2-dimensional, kinesiology-based multicomponent definition of each pitching style was formulated and used to categorize the included pitchers into the TF and DD groups. Statistical comparisons and contrasts were made using chi-square and Pearson correlation tests.Results:Included were 223 MLB pitchers (mean ± SD age, 27.5 ± 3.6 years; body mass index [BMI], 27.6 ± 2.2; throwing velocity, 92.9 ± 2.6 mph [149.5 ± 4.2 km/h]) who underwent UCLR between 2007 and 2017. Of these pitchers, 162 were categorized as TF pitchers (72.6%) and 61 as DD pitchers (27.4%). Pitching velocity for injured pitchers was significantly correlated to BMI (P < .001). We found no significant associations of pitching style with year of UCLR (P = .941), BMI (P = .549), age (P = .647), handedness (P = .501), or average pitch velocity (P = .921).Conclusion:The study findings demonstrated that a higher proportion of UCL-injured MLB pitchers (72.6%) used the TF pitching style. Further research is needed to explore the potential association between pitching style and UCL injury.

Decreased Upward Vertical Movement for Fastballs After Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers

PurposeTo analyze the velocity and movement of the 4-seam fastball, curve, and slider thrown before and after ulnar collateral ligament reconstruction (UCLR) in Major League Baseball pitchers using PITCHf/x data.MethodsVelocity and movement data of the 4-seam fastball, curve, and slider were collected for 3 time frames (12-24 months before the date of UCLR as an uninjured baseline, 12-24 months after the date of UCLR, and 24-36 months after the date of UCLR). Pitchers were separated into 3 age groups (<26, 26 to 31, and >31 years). A paired t-test for means was used to assess mean differences between 2 time periods and a generalized linear model, with time-dependent covariance structure and age group as a covariate, was used to determine differences across time. All analyses were performed using SAS, version 9.4.ResultsVertical movement of the 4-seam fastball decreased in the 24 to 36 months’ postoperative time frame, compared with 12 to 24 months’ preoperatively (9.46 to 9.14 inches, P = .032). Movement decreases in the 4-seam fastball were not age-related. Velocity did not significantly change for any pitch and movement did not change for the slider or curve pitches.ConclusionsFollowing UCLR, Major League Baseball pitchers experienced no changes in horizontal or vertical movement or velocity of the curve or slider in either time frame. Decreased upward vertical movement of the fastball occurred after UCLR at final follow-up, but no change was observed in velocity. Similar trends in pitch movement and velocity effects were observed regardless of age.Level of EvidenceIV, case series.

Revision ulnar collateral ligament reconstruction in Major League Baseball pitchers: effects of fastball velocity and usage.

Ulnar collateral ligament (UCL) tears are prevalent in Major League Baseball (MLB) pitchers and can cause significant loss of time with varying reports of impact on performance. Revision UCL reconstruction (UCLR) is becoming increasingly common, with little known about the effects on fastball (FB) velocity and usage (FB%) in this setting. The purpose was to evaluate the effect of revision UCLR on MLB pitchers with respect to postoperative FB velocity and FB% at 1 and 2 years after return to play. The hypothesis was postoperative FB velocity and FB% would significantly decrease vs. prerevision levels, and that revision UCLRs would result in significantly decreased FB velocity and FB% in comparison to a matched group of MLB pitchers after primary UCLR. Twenty-one pitchers who underwent revision UCLR and returned to MLB play were identified from public records from 2008-2021. The PITCHf(x) system collected FB velocity for 4-seam (4FB) and 2-seam (2FB) fastballs and total FB% for pitchers in the prerevision year as well as the 2 years after return. A matched control group of pitchers who underwent primary UCLR was used for comparison. There were no significant differences in FB velocity between prerevision levels (4FB 92.9 mph, 2FB 91.4 mph) and years 1 (4FB 92.5 mph, 2FB 91.2 mph) and 2 (4FB 93.4 mph, 2FB 91.1 mph) after revision UCLR. FB% decreased from the prerevision season (60.1) and the first (56.2, P=.036) and second years (52.5, P=.002) after return. There were no significant differences between FB velocity and FB% or between the revision and primary UCLR groups. Pitchers returning to the MLB level after revision UCLR can expect similar FB velocity to their prerevision FB velocity and to pitchers undergoing primary UCLR; however, they do demonstrate a decrease in FB%, which may suggest less confidence in their FB after RTP.

Paper 12: Revision Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers: Effect on Fastball Velocity and Usage

Objectives:Ulnar collateral ligament (UCL) tears are prevalent in Major League Baseball (MLB) pitchers and cause significant loss of time with varying reports of impact on performance. Revision UCL reconstruction (UCLR) is increasingly common, with little known about the effects on both fastball (FB) velocity and usage (%) in this setting. The purpose of this study was to evaluate the effect of revision UCLR on MLB pitchers with respect to post-operative FB % and velocity at one and two years after return-to-play. The hypothesis was that post-operative FB usage (FB%) and velocity would significantly decrease versus pre-injury levels in the revision UCLR group, and that revision UCLRs would result in significantly decreased FB % and velocity in comparison to a matched group of MLB pitchers after primary UCLRs.Methods:Public records were used to identify MLB pitchers from 2008 to 2020 who underwent a revision UCLR. The PITCHf/x system, which was installed in 2007 and is a standardized recording of all pitches thrown in MLB stadiums, collected FB velocity for four-seam (4FB) and two-seam (2FB) fastballs and total FB % for pitchers in the pre-injury year as well as the first two years after return. A matched control group of pitchers who underwent primary UCLR was used for comparison.Results:Nineteen pitchers fit the study criteria. There were no significant differences in the revision UCLR group in FB velocity between pre-injury levels (4FB 92.87 mph, 2FB 91.43 mph) and years one (4FB 92.55 mph, p=.375) (2FB 91.2 mph, p=0.448) and two (4FB 93.38 mph, p=.695) (2FB 91.59 mph, p=0.806) after return (Table 1). There were also no significant differences in FB % usage between the pre-injury season (60.4) and first (56.5, p=.095) or second years (52.5, p=.053) after return (Table 1). In terms of walks and hits per innings pitched (WHIP), strikeouts per 9 innings (K/9), and walks per 9 innings (BB/9), the only significant difference between pre-injury and post-injury outcomes was a significant higher K/9 in the first season after return (p=0.031) (Table 1).There were no significant differences between FB velocity or % usage between the revision and primary UCLR groups at any time point (Tables 2-4). There were also no significant differences in the revision and primary UCLR groups between WHIP, K/9, or BB/9 with the exception of lower WHIP (p=0.015) and K/9 (p=0.001) in the pre-injury season (Tables 2-4).Conclusions:In pitchers that return to the MLB level, there were no significant differences in FB velocity versus their pre-injury levels or in comparison to pitchers after primary UCLR. While not statistically significant, a trend was demonstrated that there was a clinically relevant decrease in FB % usage, potentially suggesting less confidence in their FB.Table 1.Comparison of major league baseball (MLB) revision ulnar collateral ligament reconstruction (UCLR) between pre-injury and post-operative performance. The pre-injury performance was collected for the year prior to injury while the post-operative performance was collected for the first and second years after return-to-play. Statistical comparisons were made between pre-injury performance versus the performance at 1 and 2 years after return to the MLB. Fastball (FB) velocity reported as a mean in miles-per-hour (mph). WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significantTable 2.Comparison of major league baseball (MLB) pitchers with revision ulnar collateral ligament reconstruction (UCLR) versus a group of primary UCLR (controls) in their pre-injury season prior to their respective surgical intervention. Fastball (FB) velocity reported as a mean in miles-per-hour (mph).. WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significantTable 3.Comparison of major league baseball (MLB) pitchers with revision ulnar collateral ligament reconstruction (UCLR) versus a group of primary UCLR (controls) in their first season after return to play. Fastball (FB) velocity reported as a mean in miles-per-hour (mph). WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significantTable 4.Comparison of major league baseball (MLB) pitchers with revision ulnar collateral ligament reconstruction (UCLR) versus a group of primary UCLR (controls) in their second season after return to play. Fastball (FB) velocity reported as a mean in miles-per-hour (mph). WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significant

Using Advanced Data to Analyze the Impact of Injury on Performance of Major League Baseball Pitchers: A Narrative Review

Major league baseball (MLB) pitchers are at risk of numerous injuries during play, and there is an increasing focus on evaluating their performance in the context of injury. Historically, performance after return to play (RTP) from injury has focused on general descriptive statistics, such as innings or games played, or rate statistics with inherent variability (eg, earned run average, walks and hits per inning pitched, strikeouts per 9 innings, or walks per 9 innings). However, in recent years, MLB has incorporated advanced technology and tracking systems in every stadium, allowing for more in-depth analysis of pitcher-specific data that are captured with every pitch of every game. This technology allows for the ability to delve into the pitching performance on a basis that is more specific to each pitcher and allows for more in-depth analysis of different aspects of pitching performance. The purpose of this narrative review was to illustrate the current state of injury recording for professional baseball pitchers, highlight recent technological advances in MLB, and describe the advanced data available for analysis. We used advanced data in the literature to review the current state of performance analysis after RTP in MLB pitchers after injury. Finally, we strived to provide a framework for future studies to more meticulously assess RTP performance given the current available resources for analysis.

Differences in Glenohumeral Range of Motion and Humeral Torsion Between Right-Handed and Left-Handed Professional Baseball Pitchers

Background: Elite pitchers have demonstrated significant differences in glenohumeral range of motion and humeral torsion compared with the nonthrowing population. Furthermore, abnormal shoulder range of motion measurements have been associated with different injury risks and challenges in assessing rehabilitation progress. Variations in range of motion and torsion due to handedness in the asymptomatic professional population have yet to be investigated in the literature. Hypothesis: No significant differences in glenohumeral range of motion and humeral torsion would exist between asymptomatic right- and left-handed professional pitchers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: 217 Major League Baseball pitchers from a single organization were evaluated over a 7-year period between 2013 and 2020. Range of motion was measured with a standard goniometer. Ultrasound scanning was used to determine neutral position of the shoulder, and the degree of humeral torsion was measured with a goniometer. Results: Right-handed pitchers demonstrated significantly greater values of glenohumeral external rotation (118.5° vs 112.7°; P < .001) in their throwing arms compared with their left-handed counterparts. Right-handed pitchers also showed greater values of glenohumeral internal rotation deficit (13.9° vs 4.8°; P < .001) and side-to-side differences in humeral retrotorsion (−23.1° vs −2.2°; P < .001). Left-handed pitchers demonstrated significantly greater flexion deficits in the throwing arm compared with their right-handed counterparts (7.5° vs 0.0°; P < .001). Conclusion: In the throwing arm, right-handed pitchers demonstrated significantly greater measures of external rotation, glenohumeral internal rotation deficit, and humeral retrotorsion compared with left-handed counterparts. Furthermore, right-handed pitchers demonstrated a significant side-to-side difference in retrotorsion, whereas left-handed pitchers did not. However, left-handed pitchers demonstrated a side-to-side shoulder flexion deficit that was not present in the cohort of right-handed pitchers. The correlation between humeral retrotorsion and increased external rotation indicates that osseous adaptations may play a role in range of motion differences associated with handedness. Additionally, these findings may explain observed differences in several throwing metrics between right- and left-handed pitchers. Knowledge of these differences can inform rehabilitation programs and shoulder maintenance regimens.

Paper 09: Differences in Glenohumeral Range of Motion and Humeral Torsion Between Right-Handed and Left-Handed Major League Baseball Pitchers.

Objectives:Substantial differences in throwing metrics, like velocity, spin rate and pitcher break, have been observed between left and right-handed pitchers. Elite pitchers have demonstrated significant changes in glenohumeral range of motion and humeral torsion compared to the normal population. Differences in these anatomical parameters between left and right-handed pitchers may explain these performance trends. Furthermore, changes in shoulder range of motion measurements have been associated with different injury risks and challenges in assessing rehabilitation progress. This study seeks to determine if differences in glenohumeral range of motion and humeral torsion exist between left-handed and right-handed pitchers.Methods:217 MLB pitchers from a single organization were evaluated over a 7-year period from 2013-2020. Range of motion was evaluated by three trained examiners using a Standard Goniometer. Ultrasound scanning was used to determine neutral position of the shoulder and the degree of humeral torsion was measured with a goniometer. The mean and standard deviation were assessed for normality using Shapiro Wilk. Differences between right and left-handed pitchers were assessed using one-way ANOVA. Arm effects were assessed using paired samples t-tests.Results:Right-handed pitchers showed, on average, 13.9 degrees more shoulder external rotation range in their dominant arm compared with their non-dominant arm, whereas left-handers averaged only 2.2 degrees. RHPs showed greater asymmetries in shoulder internal rotation range (13.9 vs 4.8 degrees) and humeral torsion (-23.1 vs -2.2 degrees). Left-handed pitchers showing significantly greater range of non-dominant shoulder flexion (165.8 vs 160.7 degrees) leading to greater flexion deficits in the dominant arm compared to their right-handed counterparts, (7.5 vs 0.0 degrees).Conclusions:Right-handed pitchers demonstrate significantly greater measures of external rotation, humeral retrotorsion, and shoulder flexion compared to left-handed counterparts. The correlation between humeral retrotorsion and increased external rotation indicate that osseus adaptations are a major contributor to range of motion differences associated with handedness. Additionally, these findings may explain observed differences in several throwing metrics between right and left-handed pitchers. Furthermore, knowledge of these differences can inform rehabilitations programs and shoulder maintenance regimens.Table 1.Range of Motion Variables for Right Handed (RHP) and Left Handed (LHP) Professional Baseball Pitchers.*Table 2.Average Velocity in Miles per Hour by Pitch Type and Pitcher Handedness, 2017-2020.a Figure 1.Scatter chart showing the correlation between dominant-arm retrotorsion and external rotation gain in the throwing arm of all pitcher’s studied. As retrotorsion increased, the degree of external rotation also increased. Right-handed pitchers were more likely to have higher degrees of both retrotorsion and external rotation gain. Negative values indicate retrotorsion.Figure 2.Box and whisker plot showing the difference in dominant-arm retrotorsion in the dominant throwing arm in left and right-handed pitchers. Dominant-arm| retrotorsion is the difference in torsion between the dominant throwing and non-throwing arm. Right-handed pitchers demonstrated significantly more retrotorsion (negative torsion) in the dominant throwing arm compared to left-handed pitchers.

Biomechanical Comparison of Ulnar Collateral Ligament Reconstruction With and Without Suture Augmentation

Background: A common concern associated with elbow ulnar collateral ligament (UCL) reconstruction is the amount of time required for recovery and rehabilitation. For example, for Major League Baseball pitchers, the average time to return to competition ranges from 13.8 to 20.5 months. Suture tape augmentation has shown the ability to provide additional soft tissue stability across other joints in the body. By providing an additional checkrein to the UCL reconstruction while the graft is healing, it may be possible to accelerate the rehabilitation process in overhead athletes and thus effect a quicker return to sports. Purpose: To compare elbow valgus stability and load to failure between UCL reconstruction with and without suture tape augmentation. Study Design: Controlled laboratory study. Methods: Fresh-frozen cadaveric elbows (N = 24) were dissected to expose the UCL. Medial elbow stability was tested with the UCL intact, deficient, and reconstructed utilizing the 3-strand docking technique with or without suture augmentation. A 3-N·m valgus torque was applied to the elbow, and valgus rotation of the ulna was recorded via motion-tracking cameras as the elbow was cycled through a full range of motion. After kinematic testing, reconstructed specimens were loaded to failure at 70° of elbow flexion. Results: UCL-deficient elbows demonstrated significantly greater valgus rotation when compared with intact and internally braced reconstructed elbows at every angle of flexion tested and when compared with unbraced UCL-reconstructed elbows at 50° to 120° of flexion (P < .05). There were no significant differences between intact and UCL-reconstructed elbows with and without suture augmentation at any flexion angle tested. When loaded to failure, unbraced reconstructed elbows failed at a significantly lower torque as compared with elbows with UCL reconstruction with suture tape augmentation (P < .01). Conclusion: In this cadaveric model, 3-strand UCL reconstruction with suture augmentation did not overconstrain the elbow throughout all flexion angles when compared with the native state and UCL reconstruction alone, while providing greater load to failure. Clinical Relevance: Suture tape augmentation may provide the additional strength necessary to accelerate rehabilitation after UCL reconstruction.

Ulnar Collateral Ligament Reconstruction Does Not Decrease Spin Rate or Performance in Major League Pitchers

Background: Ulnar collateral ligament reconstruction (UCLR) is commonly performed in Major League Baseball (MLB) pitchers, with variable reported effects on velocity and traditional rate statistics. Currently, no studies have evaluated spin rate in the context of return to play (RTP) after injury. Greater spin rate has become increasingly sought after in the baseball community, as it is believed to be a vital aspect of pitch effectiveness. Purpose/Hypothesis: The purpose was to evaluate the effect of primary UCLR on fastballs (FB) and sliders (SL) of MLB pitchers in terms of spin rate, velocity, hard-hit rate, and whiff rate. It hypothesized that the post-UCLR FB and SL spin rates, velocity, and whiff rate would be significantly decreased versus their pre-UCLR levels, while the FB and SL hard-hit rates would be higher in comparison with pre-UCLR levels. Study Design: Case series; Level of evidence, 4. Methods: In total, 42 pitchers who underwent UCLR and returned to MLB play were identified from public records from 2016 to 2019. The Statcast system was used to collect spin rate, velocity, hard-hit rate, and whiff rate for 4-seam FB (4FB), 2-seam FB (2FB), and SL for pitchers in the preinjury year as well as the 2 years after return from UCLR. Data were analyzed using the appropriate statistical tests. Results: A total of 36 pitchers met the inclusion criteria, and 31 of the eligible 36 players (86.1%) were able to return to MLB pitching (RTP). There were no significant decreases for 4FB, 2FB, or SL in spin rate, measured in revolutions per minute (rpm), when comparing preinjury levels with the first and second seasons after return. There was a significant decrease in velocity for the 2FB in the first season (92.9 vs 93.7 miles per hour [mph]; P = .045) but not the second season (93 mph; P = .629) after RTP in comparison with pre-UCLR levels. For the 2FB, there was a significant increase in spin rate between preinjury and RTP season 2 (2173.5 vs 2253 rpm; P = .022). For the SL, there was a significant increase in spin rate between preinjury and RTP season 2 (2245.1 vs 2406 rpm; P = .016). Conclusion: A cohort of MLB pitchers who underwent UCLR and returned to the MLB level demonstrated no significant decreases in the spin rate, velocity, whiff rate, or hard-hit rate of 4FB, 2FB, or SL at 2 years after UCLR.

Performance metrics and economics of superior labrum anterior-posterior tear repairs in Major League Baseball pitchers.

BackgroundSuperior labrum anterior-posterior tears (SLAP) can be a career-altering injury for Major League Baseball (MLB) pitchers. Surgery and postoperative rehabilitation keep pitchers on the injured list (IL) for extended time, which results in a significant cost to a team. To date, no analyses have focused on the financial cost of SLAP repairs in MLB pitchers.MethodsA retrospective review of MLB pitchers with SLAP repair from 2004 to 2019 was conducted utilizing IL and financial contract data from the MLB website. Cost of injury was calculated from salary of the player. Performance metrics including earned run average, walks + hits per innings pitched, and innings pitched (IP) were averaged for one and all seasons played before and after injury. Return to play and return to prior performance rates were calculated and reported.ResultsOf the 55 players identified, 22 players (40%) returned to play and 18 of these 22 players (82%) returned to prior performance. Annual cost increased over the study period (R2 = 0.288) averaging $3.5 million, and a stable average of 172 days was spent on the IL (R2 = 0.001). Performance was negligible except IP (106.95 vs. 50.85; P < .01) for 1 season before and after injury. For all seasons, earned run average and walks + hits per innings pitched significantly increased (4.13 vs. 5.19; P = .030, and 1.36 vs. 1.53; P = .033, respectively), while IP downtrended without significance (P = .058).ConclusionSLAP repairs in MLB pitchers have significant financial impact and time spent on the IL, which surprisingly has not changed over time. It is encouraging to know return-to-play pitchers return without profound decline in performance level following SLAP repair.

Thoracic Outlet Syndrome in Major League Baseball Pitchers: Return to Sport and Performance Metrics After Rib Resection.

Background:Thoracic outlet syndrome (TOS) is a rare injury that affects Major League Baseball (MLB) pitchers and is often corrected with surgical resection of the first rib. There are limited return-to-play (RTP) data for this surgery in MLB pitchers.Hypothesis:It was hypothesized that MLB pitchers who undergo first rib resection for TOS will show (1) a high rate of RTP, (2) no difference in postoperative career length compared with controls, (3) no difference in pre- and postoperative performance, and (4) no difference in postoperative performance compared with controls.Study Design:Cohort study; Level of evidence, 3.Methods:This retrospective cohort study evaluated MLB pitchers with neurogenic or vascular TOS who underwent rib resection surgery between January 1, 2001, and December 31, 2019. Players were identified through public injury reports from press releases, the MLB website, MLB team injury reports, and blogs. A demographics- and performance-matched control group was generated for comparison. Each player in the control group was given an index year that corresponded to the surgery year of the case group. Performance data included innings pitched (IP), games played (GP), earned run average (ERA), complete GP, shutouts, saves, hits, runs, home runs (HR), walks, strikeouts (K), walks plus hits per IP (WHIP), and earned runs (ER).Results:We identified 26 MLB pitchers who underwent rib resection for neurogenic or vascular TOS; 21 players (81%) had a successful RTP. Pitchers were 30 ± 3.6 years old at the time of surgery and had played 6.2 ± 3.5 seasons before undergoing surgery. Average postoperative career length was 3.1 ± 2.0 seasons, with an average time from surgery to RTP being 10 ± 4.7 months. Pitchers who RTP showed no significant differences in performance metrics compared with controls. Players pitch 0.94 (P < .05) more IP/GP in the season directly following RTP compared with the season before surgical intervention.Conclusion:MLB pitchers undergoing rib resection for TOS demonstrated (1) high RTP rates following rib resection, (2) no difference in postoperative career length compared with controls, (3) improvement in postoperative performance, and (4) no difference in postoperative performance compared with controls.

Predicting Multiple Injuries to Major League Baseball Pitchers: A Logistic Regression Analysis over the 2009 – 2019 Regular Seasons

ABSTRACT In Major League Baseball (MLB), player injuries requiring injured list (IL) stints are common occurrences during the regular season. Injuries to pitchers may be of specific interest to prevent and detect as they may have a detrimental effect on team performance. In the present study, the effect between team wins and frequency of pitcher injuries is assessed over the 2009–2019 regular seasons (a total of n = 2,584 pitcher injuries were analysed). The study further aimed to determine if changes in pitcher performance, as quantified by changes in common pitching statistics, including strikeout and walk percentage, can predict whether a pitcher, who has already incurred an IL stint, will require a second IL stint over the same time period. Results suggest that while only a weak relationship exists between team wins and frequency of pitcher injuries, that a decrease in strikeout percentage for a pitcher returning from the IL is associated with an increased likelihood of a second IL stint. Future research should take into consideration a player’s value or contribution to their team’s success when assessing the effect injuries have on team performance as well as the type of injury sustained.