Pitch Count Research Articles

Game-Day Pitch and Throw Count Feasibility Using a Single Sensor to Quantify Workload in Youth Baseball Players.

Pitch count recommendations are used to reduce injury risk in youth baseball pitchers and are based chiefly on expert opinion, with limited scientific support. Furthermore, they only account for pitches thrown against a hitter and do not include the total number of throws on the day a player pitched. Currently, counts are recorded manually. To provide a method using a wearable sensor to quantify total throws per game that is compliant with Little League Baseball rules and regulations. Descriptive laboratory study. Eleven male baseball players (age, 10-11 years) from an 11U (players 11 years and younger) competitive travel team were evaluated over a single summer season. An inertial sensor was placed above the midhumerus of the throwing arm and was worn during baseball games across the season. A throw identification algorithm capturing all throws and reporting linear acceleration and peak linear acceleration was used to quantify throwing intensity. Pitching charts were collected and used to verify actual pitches thrown against a hitter in a game versus all other throws identified. A total of 2748 pitches and 13,429 throws were captured. On the day a player pitched, he averaged 36 ± 18 pitches (23%) and 158 ± 106 total throws (pitches in game as well as all warm-up pitches and other throws during game). In comparison, on a day a player did not pitch, he averaged 119 ± 102 throws. Across all pitchers, 32% of all throws were low intensity, 54% were medium intensity, and 15% were high intensity. The player with one of the highest percentages of high-intensity throws did not pitch as their primary position, while the 2 players who pitched most often had the lowest percentages. Total throw count can be successfully quantified using a single inertial sensor. Total throws tended to be higher on days a player pitched compared with regular game days without pitching. This study provides a fast, feasible, and reliable method to obtain pitch and throw counts so that more rigorous research on contributing factors to arm injury in the youth athlete can be achieved.

Most high school baseball pitchers are using weighted ball throwing programs to increase ball velocity: crosssectional analysis of US high school pitchers

Weighted-ball velocity training programs are popular but may be associated with increased injury risk. The purpose of this study was to determine the current frequency of these programs, as well as their association with range of motion, strength, velocity, injury, and utilization in high school baseball pitchers. This was a multicenter, prospective, community-based study including high schools from the Northeastern, Southeastern, Midwestern, and Western regions of the United States. Preseason pitchers were surveyed about their use of weighted ball velocity programs and history of injury. Preseason pitchers underwent standardized physical examinations and pitch velocity was measured. During a single high school season, pitch counts and injury incidence were prospectively collected. In total, 115 pitchers were recruited, of whom 63% had participated in a weighted ball program. There were no differences in range of motion or strength between groups who used weighted balls and those who did not. Pitchers that utilized weighted ball programs demonstrated a higher average fastball velocity (114.26 vs. 106.22 km/h [71 vs. 66 mph]; P < .001) as well as peak fastball velocity (115.87 vs. 109.44 km/h [72 vs. 68 mph]; P= .001) compared to those that did not use weighted ball programs. Pitchers that utilized weighted ball programs were no more likely to be single-sport athletes (44%) than those who were multisport athletes (49%, P= .667). Within the group who had used a weighted ball program 29% (13/45) reported a history of injury and within the group who had not used a weighted ball program 25% (10/40) reported a history of injury (P= .687). As only a single injury occurred in the entire cohort, comparison of injury rates could not be completed. In this prospective study, the majority of high school pitchers reported using weighted ball programs to increase velocity, and these programs were associated with increased average and peak velocity compared to pitchers who did not use weighted ball programs. There were no significant differences in injury history between the 2 groups. Further study is necessary to understand the injury risk associated with weighted ball programs.

Relationship Between Pitch Counts and Shoulder Strength in Collegiate Baseball Players.

Gagnon, A, Payette, J, Park, M, Juras, K, and Slater, L. Relationship between pitch counts and shoulder strength in collegiate baseball players. J Strength Cond Res 37(9): 1860-1864, 2023-Large volumes of throwing leads to changes in shoulder strength that have been associated with increased risk of injury. The purpose of this study was to investigate the relationship between throwing volume and eccentric shoulder strength. Twelve NCAA Division I baseball pitchers volunteered to participate. Prepractice and postpractice eccentric shoulder strength was measured using a handheld dynamometer at 30°/second. Change in strength was calculated as the prepractice strength measure subtracted from the postpractice strength measure. After initial testing, subjects self-reported pitch counts before completing postpractice strength testing. Subjects were separated into high-strength and low-strength groups based on the median external rotation strength. Paired t -tests were used to compare change in shoulder strength and Pearson's r correlations were used to quantify the association between pitches and change in strength. There were no changes between prestrength and poststrength assessments in external rotation strength or internal rotation strength for the entire group. When divided into strength groups, correlations between strength and total pitches were nonsignificant for the high-strength group but were strong for both external rotation ( r = -0.87, p = 0.025) and internal rotation ( r = -0.91, p = 0.013) in the low-strength group. Pitchers with lower shoulder eccentric strength at baseline demonstrated greater declines in strength, whereas pitchers with higher shoulder eccentric strength did not demonstrate changes in strength. Changes in strength during practice could lead to compensatory movement that may predispose athletes to injury. Sport performance professionals may benefit from obtaining eccentric shoulder strength to assist with performance periodization and rehabilitation after injury.

Sensor Location Matters When Estimating Player Workload for Baseball Pitching.

Estimating external workload in baseball pitchers is important for training and rehabilitation. Since current methods of estimating workload through pitch counts and rest days have only been marginally successful, clubs are looking for more sophisticated methods to quantify the mechanical loads experienced by pitchers. Among these are the use of wearable systems. While wearables offer a promising solution, there remains a lack of standards or guidelines for how best to employ these devices. As a result, sensor location and workload calculation methods vary from system to system. This can influence workload estimates and blur their interpretation and utility when making decisions about training or returning to sport. The primary purpose of this study was to determine the extent to which sensor location influences workload estimate. A secondary purpose was to compare estimates using different workload calculations. Acceleration data from three sensor locations-trunk, throwing upper arm, and throwing forearm-were collected from ten collegiate pitchers as they threw a series of pitches during a single bullpen session. The effect of sensor location and pitch type was assessed in relation to four different workload estimates. Sensor location significantly influenced workload estimates. Workload estimates calculated from the forearm sensor were significantly different across pitch types. Whole-body workload measured from a trunk-mounted sensor may not adequately reflect the mechanical loads experienced at throwing arm segments. A sensor on the forearm was the most sensitive to differences in workloads across pitch types, regardless of the calculation method.

Variability in Pitch Count Limits and Rest Day Requirements by State: Implications of Season-Long Pitch Counts in High School Baseball Pitchers

Background: It is unknown how different pitch count limits and rest day requirements affect cumulative pitch counts during a baseball season. Purpose: To determine (1) the variability of pitch count rules in high school baseball and (2) the theoretical effect of different pitch count limits and rest day combinations on game, weekly, and seasonal pitch totals in high school baseball pitchers. Study Design: Cross-sectional study. Methods: Pitch count rules for the 2019-2020 academic year for 48 sanctioned states were recorded from each state’s athletic association website. Maximum pitch count limits were recorded along with the number of pitches allowed before requiring 0 to 5 rest days before the next pitching outing. Rules were also analyzed for several distinctions, including the athlete’s level of competition, age, and grade. To determine the effect of pitch count rules and rest days, a theoretical 3-month season was calculated in the following scenarios: (1) variable maximum pitch count limits with a universal 3-day rest requirement, (2) universal 110 pitch count limit with variable rest day requirements (3, 4, or 5 days), and (3) actual pitch count limits and required rest days for every state assuming pitchers throw as many pitches as allowed. Analysis of variance and Student t tests were used to compare between-group and intragroup seasonal pitch totals based on variations in required rest days. Results: The most common maximum pitch count limit for a varsity high school athlete was 110 pitches (range, 100-125 pitches) with 4 rest days (range, 0-5 days). We found that 23 states (48%) did not make distinctions for pitch count rules based on the athlete’s level of competition, age, or grade. We noted a 25% increase in total seasonal pitch counts between the smallest and largest pitch count limit when assuming constant 3-day rest. We found a 53% difference in total seasonal pitch count when rest days varied between 3 and 5 days with a constant 110-pitch limit. Allowing 140 pitches in a 4-day span without a specific rest day requirement resulted in the highest seasonal pitch count (Nevada). There was a 49% difference in maximum seasonal pitch counts between the most and least restrictive states (P < .001). Submaximum pitch limits resulted in higher seasonal pitch counts than maximum pitch limits in 56% of states. Conclusion: Pitch count rules vary widely by state. Required rest days influenced total seasonal pitch counts more than maximum or submaximum pitch count limits.

Including Modifiable and Nonmodifiable Factors Improves Injury Risk Assessment in Professional Baseball Pitchers.

To (1) evaluate an injury risk model that included modifiable and nonmodifiable factors into an arm injury risk prediction model in Minor League Baseball (MiLB) pitchers and (2) compare model performance separately for predicting the incidence of elbow and shoulder injuries. Prospective cohort. A 10-year MiLB injury risk study was conducted. Pitchers were evaluated during preseason, and pitches and arm injuries were documented prospectively. Nonmodifiable variables included arm injury history, professional experience, arm dominance, year, and humeral torsion. Modifiable variables included BMI, pitch count, total range of motion, and horizontal adduction. We compared modifiable, nonmodifiable, and combined model performance by R2, calibration (best = 1.00), and discrimination (area under the curve [AUC]; higher number is better). Sensitivity analysis included only arm injuries sustained in the first 90 days. In this study, 407 MiLB pitchers (141 arm injuries) were included. Arm injury incidence was 0.27 injuries per 1000 pitches. The arm injury model (calibration 1.05 [0.81-1.30]; AUC: 0.74 [0.69-0.80]) had improved performance compared to only using modifiable predictors (calibration: 0.91 [0.68-1.14]; AUC: 0.67 [0.62-0.73]) and only shoulder range of motion (calibration: 0.52 [0.29, 0.75]; AUC: 0.52 [0.46, 58]). Elbow injury model demonstrated improved performance (calibration: 1.03 [0.76-1.33]; AUC: 0.76 [0.69-0.83]) compared to the shoulder injury model (calibration: 0.46 [0.22-0.69]; AUC: 0.62 [95% CI: 0.55, 0.69]). The sensitivity analysis demonstrated improved model performance compared to the arm injury model. Arm injury risk is influenced by modifiable and nonmodifiable risk factors. The most accurate way to identify professional pitchers who are at risk for arm injury is to use a model that includes modifiable and nonmodifiable risk factors. J Orthop Sports Phys Ther 2022;52(9):630-640. Epub: 9 July 2022. doi:10.2519/jospt.2022.11072.

Effect of Pitching Restrictions and Mound Distance on Youth Baseball Pitch Counts

Background:Studies have shown that higher pitch counts are directly related to a greater incidence of elbow and shoulder pain among youth baseball pitchers.Purpose/Hypothesis:The purpose of this study was to examine the effect of different pitching restriction rules on the number of pitches thrown in youth baseball leagues. We hypothesized that more pitches would be thrown in leagues with inning restrictions versus leagues with pitch count restrictions as well as in leagues with a longer mound distance (from pitching mound to home plate).Study Design:Cohort study; Level of evidence, 2.Methods:Pitch count data were collected for 2 consecutive years over a 10-week season from 3 different leagues of 9- to 12-year-old baseball players in a single city. The Eastern league had a pitch count restriction and 46-ft (14.02-m) mound distance. The Southeastern and South leagues’ pitching restrictions were based on innings per week. The Southeastern league had a 50-ft (15.24-m) mound distance, while the South league had a 46-ft mound distance. Comparisons of total seasonal pitches thrown were made of the 3 highest-volume pitchers on each team. League averages for each value were then compared utilizing analysis of variance with Bonferroni post hoc analysis. The number of pitchers in each league who threw >600 pitches per season was compared using the chi-square test.Results:No significant difference in seasonal pitch counts or innings pitched was noted between the Eastern and South leagues, which differed only in their pitching restrictions. The Southeastern league, with a longer mound distance, was found to have higher seasonal pitch counts per thrower (598 ± 195 pitches) than the South league (463 ± 198 pitches) for the 3 highest-volume throwers for each team (P = .004). The Southeastern league also had a significantly larger number of pitchers who threw >600 pitches per season (33 vs 20 for Eastern and 13 for South; P = .009).Conclusion:There was no significant difference in seasonal pitch counts when the leagues in this study differed based on pitching restrictions. However, the league with a greater mound distance (Southeastern) had higher seasonal pitch counts for the highest-volume throwers. Pitching restrictions based on pitch counts, as opposed to innings, may be advisable.

Poster 181: Pitching Regimens and Prevalence of Injuries in Youth Fastpitch Softball Windmill Pitchers

Objectives:Female youth fastpitch softball pitchers experience stresses to their pitching arms similar to overhand baseball pitchers, placing them at increased risk of overuse injuries. However, they continue to have demanding pitching regimens without tracking of pitch counts or dedicated days of rest. Unlike youth baseball, there is scarce literature documenting incidence of injuries and pitching regimens of female youth fastpitch softball pitchers. Our purpose was to perform an analysis of youth fastpitch pitchers reported pitching regimens, levels of competition and injuries to each major joint of both the upper and lower extremities.Methods:Institutional review board approval was obtained for this survey study. This approval included a waiver of parental or informed consent. A 2-part survey was created; the first part focused on pitching regimens while the second part focused on reported injuries. The web-based survey was managed by an online survey software system (Version 1.0, 2021 SurveyPlanet, LLC). Surveys were distributed to coaches and USA softball state commissioners with available email addresses found of the USA Softball website. they were then distributed to youth fastpitch softball pitchers age 7 to 21 years old. Responses were analyzed as a whole as well as broken up into four separate age groups; less than 10 years old (Group A), 10-13 years old (Group B), 14-17 years old (Group C) and 18-21 years old (Group D). Statistical analysis was performed with a univariable and multivariable regression analysis.Results:Regarding pitching regimens in all participants, more than 89% were right handed pitchers. Greater than 90% played on a travel team, year round and participated in private pitching lessons. The majority also pitched 3-4 days per week until the 18-21 age group. The number of innings pitched per game, pitches thrown per game and total games pitched per season increased with age. Days of rest per week decreased from 2-3 days to 0-1 day over the age of 18 (Table 1). From the reported pitching injuries per age group, no injuries were reported in pitchers under 10 years old, however injuries were reported in 51% of participants age 10-13, 80% age 14-17 and 96% age 18-21. More than 85% of all pitchers with reported injuries played on a travel team, year round and participated in private lessons. The majority pitched 3-4 days per week (B 89%, C 71%), increasing frequency especially in the 18-21 age group (D 59%). Greater than 65% of pitchers with reported injuries in all age groups threw 60-100 pitches per game. More than 50% of pitchers reported pitching in 21-30+ games per season, comparable to a starting position. Days of rest per week also decreased from 2-3 days to 0-1 day over age 18 (Table 2). The most common reported injury was to the shoulder. Elbow, knee, foot and ankle as well as back injuries were also reported in up to 40% of participants. Surgeries were reported only in participants over 14 years old about the shoulder, elbow and knee (Figure 1). Other important trends in pitchers with reported injuries were greater than 60% starting pitching before age 9 (B 89%, C 62%, D 64%). 62-68% of pitchers over 14 years old threw five or more different pitches. Unfortunately, approximately 10% (8/85) of injured pitchers did not return to pitching following their injury. Statistical analysis demonstrated pitchers were approximately two times more likely to have an injury if they threw 60-100 pitches per game (P 0.16, P 0.25). However, pitchers age 14-17 were 5-6 times more likely to have an injury than younger groups (P <0.001) and pitchers age 18-21 were 28-30 times more likely to have an injury than younger groups (P 0.002) As a single variable, participants who began pitching at less than 9 years old were two times more likely to have an injury than participants beginning over 10 years old (P 0.14, P 0.97) (Table 3).Conclusions:The windmill motion of fastpitch pitchers is not as benign as once thought. Young female pitchers are experiencing injuries at an exponentially increasing rate with age. These athletes are pitching more frequently at younger ages on year-round travel teams without concern for pitch counts or time for rest and recovery. As softball continues to grow in popularity and participation, the focus needs to turn to protecting youth pitching arms to allow for high level competition beyond high school without significant injury. A prospective study following regimens and pitch counts as well as injury surveys will help to identify risk of injury and provide guidelines for youth pitchers and coaches.Table 1.Pitching Regimens in All ParticipantsTable 2.Pitching Regimens in Injuried Participants Figure 1.Table 3.Univariable and Multivariable Regression Analysis (Outcome = Any Type of Injury)

Interval Throwing Programs at Distances Beyond 150 Feet Can Be Equivalent to Pitching Over Five Innings

To determine the cumulative elbow varus torque (EVT) experienced during created interval throwing programs (ITP) and derive innings pitched equivalent for each step. High school pitchers wearing the motusBASEBALL sensor who had at least 50 throws at 90, 120, 150, and 180 ft and game pitches were included in this analysis. Means for EVT per throw and torque per minute were calculated at each distance. Three throwing programs were created using a template of 1 phase at each distance with 2 steps per phase. Programs varied only by number of throws per set (20, 25, and 30 throws for Program A, B, and C, respectively). Total EVT for each step, phase, and program were calculated using mean EVT per throw at each distance. Total EVT for each step and program were converted to a mean inning pitched equivalent (IPE) and maximum pitch count equivalent (MPE), respectively, using in-game pitching torque values and expected mean pitch counts (15 pitches/inning and maximum 105 pitches/game). In total, 3,447 throws were analyzed from 7 subjects (16.7 years ± 0.8 years). EVT per throw increased at each distance (range 36.9-45.5 N·m), comparable to game pitches (45.7 N·m). Mean EVT per minute was highest for 90 ft throws (193.4 N·m/min) and lowest for game pitches (125 N·m/min). Throwing Program A had the lowest range of IPE (Step 1: 2.0 and Step 8: 3.7), and Program C had the highest range (Step 1: 3.0 and Step 8: 5.6). The phases of Program A never exceeded 1MPE. Program B exceeded this threshold after Phase 1, and Program C exceeded 1MPE at every phase. Total program MPE ranged from 3.5 to 5.2 (Program A and C, respectively). Programs requiring 25 or more throws per set reached approximately 5 IPE per day. Increasing throwing repetitions by 10 throws resulted in a nearly 50% increase in IPE and MPE. IV, retrospective cohort study.

Integral Plugged Blind via in Printed Wiring Boards

Adoption of fine pitch and high lead count area array components in high-reliability applications such as military and space electronics demands high-density interconnect (HDI) features in multilayer printed wiring boards (PWBs). Usage of cap-plated fine vias that are plugged with dielectric material is one of the approaches to meet the circuit density requirements. In this article, a novel method called &#x201C;integral plugged blind via&#x201D; without secondary processing steps, such as curing and planarization, is described to realize HDI multilayer PWBs. In this method, through vias are epoxy plugged during the lamination of inner layer circuits in vacuum-assisted hydraulic press cycle. Plugged blind vias are formed as an integral part of the fabrication process. It is observed that there is no excess ooze out of resin material from the blind vias in the laminated substrate and blind vias are found to have a negligible dimple and no voids. This is attributed to the gasket effect due to the elastomeric property of specialty release films, which conform (follow) to the contour of plated through vias during the vacuum lamination cycle. Plugged blind vias are subjected to critical thermomechanical stress to evaluate interconnection integrity. It is found that there is negligible change in the resistance of vias and resin plugged vias are free from defects such as barrel crack or knee crack of plated through hole (PTH) or delamination in the cured plugged material. Robustness of these resin-filled blind vias is attributed to anchored plated barrel with the additional support provided by plugged material, which restricts the thermomechanical deformation of plated copper.

Stride Length and Torso Biomechanics As They Relate To Medial Elbow Injuries In Adolescent Aged Baseball pitchers: A Clinical Commentary

There is a limited amount of literature examining torso biomechanics and stride length while addressing their relationship to medial elbow injuries in the adolescent baseball pitcher. Anatomical changes, growth, early sport specialization, multiple team participation, mound distance, mound height, and high pitch counts place adolescent pitchers at an exceptionally higher risk for medial elbow injuries. Existing evidence indicates that decreased stride length and altered trunk rotation is correlated with increased medial elbow loading for the adolescent overhead athlete. Further research is required to quantify adequate parameters for torso kinematics, control, and their correlation to stride length, in order to positively affect the biomechanical transfer of energy and potentially prevent injuries during the overhead throwing motion. The purpose of this clinical commentary is to examine and summarize the role of torso biomechanics and stride length in relation to medial elbow injuries in adolescent baseball pitchers. Level of Evidence 5

Pediatric Softball Injuries Presenting to Emergency Departments.

This study sought to characterize the mechanisms of injury responsible for common softball-related injuries in recent years. The National Electronic Injury Surveillance System database was queried for all pediatric softball-related injuries presenting to participating US emergency departments from 2010 to 2019. Patients were classified by age as children (7-12 years), adolescents (13-18 years), or young adults (19-21 years). The case narrative of each injury was used to establish the mechanism of injury: hit by bat, hit by ball, sliding into base, collision with another player, catching, running, and throwing. Statistical weights provided by the Consumer Product Safety Commission were used to produce national injury estimates. There were an estimated 511,117 pediatric softball injuries presenting to the emergency department over the study period, with a mean patient age of 14.3 years (95% confidence interval [CI], 14.1-14.4 years). The head/neck was the most commonly affected body part, making up 30.2% of cases (95% CI, 28.2%-32.2%). Injuries to the head/neck were most often caused by being hit by the ball (78.4%; 95% CI, 76.4%-80.3%) and most commonly resulted in a superficial injury (36.9%), internal injury (22.2%), or concussion (16.3%). Foot/ankle injuries were most frequently caused by sliding into base (51.5%; 95% CI, 47.0%-55.2%) and typically resulted in a sprain/strain (65.5%). The most frequent causes of shoulder/elbow injuries were being hit by the ball (33.3%; 95% CI, 28.6%-38.3%) and throwing the ball (27.6%; 95% CI, 22.8%-32.9%). These resulted most frequently in a sprain or strain (39.5%), followed by a superficial injury (28.2%). The proportion of softball injuries affecting the shoulder and elbow and the lower extremities increased with athlete age, whereas the proportion of injuries affecting the remainder of the upper extremities decreased with athlete age. Being hit by the ball was the most common mechanism of injury, especially in the head/neck region, and shoulder/elbow injuries increase with athlete age. Coaches and leagues may consider mandating helmets for infielders and pitch counts for pitchers, especially among adolescent athletes.

Pitching Behaviors in Youth Fast-Pitched Softball: High Pitching Volumes With Unequal Pitch Counts Among Pitchers are Common.

Softball is a popular sport among youth female athletes. While youth baseball has well-established, evidence-based pitching guidelines, youth softball pitching guidelines lack both evidence and enforcement. Adherence to pitch count limits in youth softball is infrequent and results in pitchers with exceedingly high pitching volumes. Pitch counts for youth fast-pitch softball teams competing for 1 consecutive year between January 2018 to December 2019 in age groups 8 and under (8U) to 14 and under (14U) were collected. Pitching volume was assessed based on individual games, single calendar days, and tournaments in which games are played on 2 or more consecutive days. Pitchers on teams were subdivided based on pitch count volumes and compared using a logarithmic transformation and geometric mean. Data was collected for 10 teams from each age division resulting in analysis of 538 pitchers on 70 teams. The average pitcher threw 813 pitches per year and appeared in 20.0% of games while the average highest volume pitcher threw 2500 pitches per year and appeared in 54.5% of games. On average, the highest volume pitcher on each team threw 40% of all team pitches, while the 3 highest volume pitchers combined threw 82% of all team pitches. The average and high-volume pitcher threw pitches in 2 or more games on the same day in 37.5% and 48.6% of possible games while pitching 2 or more consecutive days in 64.0% and 79.6% of possible games, respectively. Softball pitchers throw high volumes of pitches while also pitching multiple days consecutively. A disparity among pitchers on softball teams exists as 40% of team pitches are thrown by 1 player and over 80% of team pitches are thrown by the top 3 pitchers. These high-volume pitchers may be engaging in unsustainable pitching practices that could predispose to injury. Level IV-cross-sectional.

Medial elbow joint space gapping associated with repetitive baseball pitching in preadolescent baseball players.

The baseball pitching motion creates valgus stress to the medial elbow, which contributes to increased medial elbow joint space gapping. The musculoskeletal systems of preadolescent baseball players are immature compared with those of adults, but it is unclear whether the repetitive pitching action causes an increase in medial elbow joint space gapping. This study aimed to examine differences in medial elbow joint space gapping based on the pitch count of preadolescent baseball players compared with those of adult players. The participants were 11 healthy preadolescent baseball players and 12 college students with baseball experience. They threw 60 maximal-effort pitches arranged into 4 sets of 15 pitches. The medial elbow joint space was measured ultrasonographically with the forearm weight before pitching and following every set of 15 pitches. Repeated-measures analysis of variance and the Bonferroni post hoc test were used to compare the medial elbow joint space among the 5 pitching sets (before pitching and after 15, 30, 45, and 60 pitches) and between the groups of preadolescent baseball players and college students. There was no significant change in the medial elbow joint space gapping of the dominant elbow based on age/pitch count (F=0.42, P=.796). There was a significant effect of pitch count (F=30.28, P<.001) and between-group effects (F=4.56, P=.045). The medial elbow joint space gapping increased significantly after 60 pitches in preadolescent baseball players (P=.023) and college students (P=.021). The medial elbow joint space gapping in preadolescent baseball players was significantly wider than that in college students (P=.007 before pitching, P=.027 at 15 pitches). Sixty repetitive pitches contributed to an increase in the medial elbow joint space gapping, regardless of age. The results of this study provide further evidence when considering pitching limitations.

Survey with Innovations to Increase Response Rate Reveals Low Compliance with Guidelines among Youth Baseball Coaches - Including a Survey of Differences between Cities.

BackgroundCompliance rates of youth baseball team coaches with guidelines regarding pitch count limits have been reported, but response rates from previous surveys have not been high, which may introduce substantial non-response bias. In addition, differences between cities in guideline compliance rates have remained unclear.PurposeThe aim of the present study was to obtain data on coach compliance with guidelines for pitch count limits with a high survey response rate. Secondary aims were to determine compliance with guidelines other than pitch count limits, and to determine whether differences in compliance exists between cities.MethodsA questionnaire was developed for coaches of youth baseball teams in Gunma to assess knowledge of and compliance with the Japan Softball Baseball Association’s recommendations for preventing injuries. In the preparation, distribution, and collection of the questionnaire, four strategies were applied to increase the response rate. The questionnaire surveyed basic descriptive information about the team and coach and coaches compliance with guidelines. Survey items were compared between compliant and non-compliant groups for pitch count limits, and by city.ResultsValid responses to the questionnaire were obtained from coaches of 58 of 62 teams surveyed for a response rate of 93.5%. Despite the fact that almost all coaches were aware of the recommendations regarding pitch count limits and felt these limits were needed, only 15.5% were compliant. For guidelines other than the pitch count limits, the recommended values were exceeded for practice time on holidays. Differences between cities were evident in the compliance rate with the pitch count limit, but no differences between cities in other items were observed.ConclusionThe results of this research revealed that compliance with pitch count limits in this sample of youth baseball coaches was much lower than previously reported. Differences between cities were identified in rates of compliance with pitch count limits. These results suggest a need to increase compliance rates with guidelines for pitch count limits and to address differences between cities.Level of EvidenceCross-sectional survey study, 3b

Trends in pediatric baseball and softball injuries presenting to emergency departments

ABSTRACT Background Millions of youth participate in baseball and softball in the United States and these youth account for a large number of pediatric sports injuries. This study sought to characterize annual, seasonal, and age-related trends in pediatric softball and baseball injuries presenting to the Emergency Department (ED). Methods The National Electronic Injury Surveillance System (NEISS) database was retrospectively examined for all softball and baseball injuries from 2010 to 2019 involving pediatric patients aged 7–21 years. Patients were classified by age as children (ages 7–13), adolescents (ages 14–18), or young adults (ages 19–21). Case narratives were used to assign mechanisms of injury. National injury estimates were calculated using statistical weights provided by the Consumer Product Safety Commission. Results An estimated 1,372,573 pediatric softball and baseball ED visits occurred from 2010 to 2019. The mean age of the patient population was 13.6 years old (95% CI = 13.5–13.8 years), and baseball athletes were younger than softball athletes (13.2 years and 14.3 years) (p < 0.01). Moreover, baseball athletes hit by the bat were younger than their softball counterparts (11.8 years and 13.4 years). Most baseball and softball injuries were the result of being hit by the ball (52.8% and 54.2%) or sliding into a base (13.1% and 15.8%). The annual number of injuries decreased during the studied time period by 41.1% for baseball injuries and by 38.3% for softball injuries. The annual number of injuries related to all injury mechanisms decreased over the studied time period for both sports, with the exception of baseball throwing injuries, which increased by 8.6%. Baseball and softball injuries were both most likely to be present to the ED on Sunday (16.3% and 17.9%) and during the Spring (53.2% and 55.3%). Conclusion Safety guidelines should focus on reducing the prevalence of injuries acquired by younger baseball and softball players during practice and educating coaches and players on existing pitch count guidelines.

Magnetic Resonance Imaging Findings of the Asymptomatic Shoulder May Impact Performance, Not Future Injury List Placement in Major League Baseball Pitchers

PurposeTo evaluate preseason shoulder magnetic resonance images (MRIs) obtained from pitchers entering either major or minor league baseball (MLB) and correlate findings with subsequent injury, operative repair, and placement on the injured list (IL).MethodsPreseason-MRI of the throwing shoulders of professional-level baseball pitchers, taken during routine evaluations at a single organization (2004-2017) were retrospectively reviewed. Publicly available databases were queried to exclude pitchers with known injuries prior to pre-signing imaging. Three blinded reviewers reviewed all MRI scans independently to evaluate for the presence of abnormalities in the rotator cuff (RTC), labrum, capsule, long-head of the biceps tendon (LHBT), and humeral head. Binary imaging findings were correlated to future placement on the IL for subsequent shoulder complaints. Bivariate statistics using Student’s t-tests and Fisher exact tests (both α = .05) were used in this study.ResultsA total of 38 asymptomatic pitchers with shoulder MRIs were included. Pitchers had a mean (±SD) age of 28.2 ± 4.9 and had pitched an average of 119.6 ± 143.8 career games. Pitchers with partial articular-sided RTC tears (P = .04) or intra-articular BT hyperintensity (P = .04) on preseason MRI demonstrated an association with the need for future surgery. Pitchers with evidence of labral heterogeneity demonstrated greater total career pitch counts (10,034.1 vs 2,465.3; P = .04). Evidence of a posterior-superior humeral cyst was associated with decreased strikeouts per 9 innings (6.1 vs 8.0; P = .039) and total strikeout percentage (16.1% vs 23.2%; P = .04).ConclusionAlthough there was a significant difference in the percent of various radiographic findings between the injured and healthy cohort, no MRI findings were predictive of future IL placement or duration of placement. The presence of a posterior superior humeral cyst was associated with decreased strikeout rates at 2 and 3 years, the presence of a labral tear was associated with decreased earned run average (ERA) at 3 years and decreased career strikeout percentages, and increased capsular signal was associated with decreased 5-year ERA.Level of EvidenceLevel IV, retrospective study.

Vocalization and other behaviors as indicators of emotional valence: The case of cow-calf separation and reunion in beef cattle

Vocalization may communicate the emotional state in vocal animals. We aimed to describe and compare vocalization and other behavioral signs of cow-calf pairs in emotionally negative and positive situations, and the potential influence of genetic group, parity category and calf sex on these signs.Forty-two beef cows (16 primiparous and 26 multiparous), and their 24 h-old calves (24 males and 18 females), with no previous separation from their mothers, were studied in Southern Brazil. The dams were daughters of Taurine crossbred mothers, 16 with Limousin (LIMO), 15 Charolais (CHAR), six Brahman (BRAH) and five Blond d'Aquitaine (BLON) bulls. We recorded 3 minute-videos to analyse animal responses to three sequential treatments: AR – arrival of cow and calf together in corral one (C1); SE – separation of the pair, calf removal from C1, isolated in corral 2 (C2), not seeing but hearing the cow; RU – reunion of calf and mother in C1. For cows and calves, the vocalization count per minute, fundamental frequency (f0), duration of the vocal call and latency to vocal response in AR, SE and RU were measured, as well as selected behaviour signals. A significant interaction effect between treatment and genetic group was observed for duration, pitch and vocalization count per minute. In SE, LIMO and CHAR cows expressed longer vocal responses than during AR, 24.6% and 18.2%, respectively, and RU (LIMO 15.7% and CHAR 33.6%). In SE, LIMO (114.2Hz) and BRAH (124.6Hz) cows showed higher f(0). CHAR and BRAH cows vocalized 2.8 and 5.1 times more frequently during SE than RU. Cows showed higher frequency of tail movements and smelling the corral in SE than in AR and RU. Cows presented higher frequency of head movement in SE as compared with RU. Calves showed greater head and body movement during SE than during AR and RU. In SE, male calves showed higher frequency of ear movements than female calves. Body movements of the cow were also more frequent during SE than in RU. Overall, cows showed higher pitch, longer vocal calls and other behavioral changes in SE, such as tail flapping, sniffing the corral, and head and body movements; calves showed higher frequency of head and body movement in SE. The results suggest that the studied indicators may be useful to identify emotionally negative situations, with genetic group and calf sex as factors which deserve further studies.

Chronic Workload, Subjective Arm Health, and Throwing Injury in High School Baseball Players: 3-Year Retrospective Pilot Study.

Baseball workloads are monitored by pitch counts, appearances, innings per appearance, ball velocity, and distance, whereas current workload standards neglect throws made during nongame situations. The association between total workloads, subjective measures, and injury in baseball is poorly understood. The question remains whether baseball athletes are at higher risk of injury by throwing more often or if they generate injury resilience when appropriately transitioned into the higher demands of throwing. Increased chronic load, along with subjective arm health measures, are related to decreased injury risk. Clinical research. Level 3. A total of 49 male baseball players (age 17.9 ± 0.4 years, height 181.8 ± 6.8 cm, body mass 80.6 ± 9.1 kg) competing at the varsity high school level were included in this 3-year retrospective data analysis from 2016 to 2019. Players wore the motusTHROW sleeve and sensor during all throwing activities. A total of 898,492 throws and 9455 athletic exposures were captured with the motusTHROW sensors. There were 24 injuries recorded throughout the 3-year analysis, with 11 throwing-related and 13 non-throwing related injuries. Results of the 1-way analysis of variance found chronic load was significantly related to throwing-injury occurrence (P < 0.01). Six of the throwing-related injuries occurred when athletes had a chronic load greater than 11.3, marking 75th percentile across all observations. There was a relationship between arm health and throwing arm-related injury occurrence (P < 0.01). Higher chronic load was associated with increased throwing-related injuries even when adjusted for arm health (P = 0.01). Specifically, injuries were more likely to occur in pitchers (either as a combination player or pitcher only) with a chronic load greater than 9.2. This study revealed a significant relationship between chronic load, subjective arm health, and throwing-related injury in varsity high school baseball players. Contrary to our hypothesis, increased chronic load was associated with increased injury risk. However, subjective arm health measures remain a relevant factor in assessing injury risk. Normative data for this population also provide key information around positional demands along with overall demands of the sport during the competitive season and off-season.

Pitching Behaviors in Youth Baseball: Comparison With the Pitch Smart Guidelines.

Background:The Pitch Smart guidelines aim to limit youth baseball pitching behaviors associated with overuse injuries. Despite many youth baseball leagues being compliant with the guidelines, during tournaments, pitch count restrictions or guidelines are often not followed.Purpose:To perform a quantitative analysis of pitch counts in youth baseball players and evaluate compliance with regard to the Pitch Smart guidelines in the tournament setting.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Included in the analysis were 100 youth baseball teams that competed in the 8-and-under to 14-and-under age divisions during the 2019 tournament season. Pitching data were compared with the Pitch Smart guidelines. Violations were identified as (1) exceeding maximum daily pitch count, (2) inadequate rest between pitching events, and (3) pitching more than 1 event on the same day. Pitcher and game factors were analyzed for possible relationships to guideline violations using mixed-effects negative binomial regression models, with comparisons of violations using rate ratios (RRs).Results:Analysis included 1046 pitchers and 2439 games. There were 1866 total Pitch Smart guideline violations, with 48.6% of pitchers having at least 1 violation. Inadequate rest was the most common reason for violation, with noncompliance occurring in 43.3% of pitchers. The highest rate of any violation (0.32 per appearance) occurred in the 8-and-under age division. High-volume pitchers had increased violation rates in each category compared with low-volume pitchers (P < .001). Violation rates were increased more than twice the rate when pitchers participated in ≥5 consecutive games without a rest day when compared with a single game (RR, 2.48; P < .001).Conclusion:Noncompliance with Pitch Smart guidelines in tournament settings occurred in more than 90% of teams and almost half of all pitchers. Factors associated with noncompliance included younger pitcher age, high-volume pitching, and pitching in multiple consecutive games. Education of tournament directors, coaches, parents, and athletes regarding pitching guidelines is warranted in order to limit the risk of injury.