Pitch Count Research Articles

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.

Relationship Between Pitch Volume and Subjective Report of Injury in High School Female Fast-Pitch Softball Pitchers.

The relationship between pitch volume and injury is well-represented within baseball literature. However, the impact of softball pitch volume on injury epidemiology is limited. The purpose was to determine if increased pitch volumes in high school-aged softball pitchers are related to increased rates of subjectively reported pain/injury. We hypothesized that pitchers with increased volumes would have higher pain/injury rates. Cross-sectional study. Level 4. A total of 28 female softball pitchers (aged 14-18 years) completed an online survey of questions pertaining to pitching history, pitch volume, and subjective report of pain or injury in the back, shoulder, and elbow. An independent-samples t test was used to (1) compare pitch volumes in those who reported pain in individual body regions (shoulder, elbow, back) compared with those who did not; (2) compare pitch volumes in those who reported pain in 0 or 1 of the regions of interest compared with 2 or 3 regions; and (3) compare the reported percentage of the past year that players reported playing through pain in players who averaged >85 compared with <85 pitches per game. Chi-square analysis was used to compare those who pitched either >85 or <85 pitches per game with regard to frequency of shoulder pain, elbow pain, back pain, seeking of medical attention, and actual injury diagnosis. Type I error was set at α = 0.05. Weekly and yearly pitch counts were higher in those reporting pain or injury (YES) than those who did not (NO) in the shoulder (pitches per week: NO = 219 ± 35; YES = 429 ± 101; P = 0.027) (pitches per year: NO = 8876 ± 946; YES = 19,195 ± 4944; P = 0.022) and back (pitches per week: NO = 188 ± 16; YES = 426 ± 90; P = 0.014) (pitches per year: NO = 8334 ± 793; YES = 18,252 ± 4340; P = 0.027). Similar results were observed for those with pain or injury reported in 2 or 3 regions compared with 0 or 1 regions (pitches per week: NO = 220 ± 38; YES = 414 ± 95; P = 0.039) (pitches per year: NO = 8765 ± 1010; YES = 18,661 ± 4623; P = 0.028). Those reporting shoulder pain or injury also reported higher pitch counts per game (NO = 71.4 ± 5.2; YES = 83 ± 4; P = 0.049), and those reporting back pain also reported playing more games per week (NO = 2.7 ± 0.2; YES = 5.2 ± 1.1; P = 0.034). Those with pitch counts of >85/game were more than twice as likely to see a physician regarding pain/injury (P = 0.027) and reported playing through pain a higher percentage of the year (>85, 49.3% ± 10%; <85, 25.2% ± 6%; P < 0.05). High pitching volumes commonly prevalent in high school-aged softball pitchers may be associated with increased pain/injury and appear related to cumulative volume. This study provides recommendations for cumulative pitch volume guidelines in softball pitchers.

Comparison of Elbow Varus Torque During Interval Throwing Programs and Gameday Pitching in High School Baseball Pitchers (125)

Objectives:Completion of an interval throwing program (ITP) is a common benchmark for return to full competition following an injury to the dominant extremity of an overhead throwing athlete. While workload management for overhead athletes has evolved, the general structure of the ITP remains relatively unexamined. Furthermore, the daily and cumulative workload of ITPs is generally unknown. An ideal ITP would allow for a gradual increase in workload that eventually approximates, but does not exceed, workload measurements attained during competition. It is currently unknown if ITPs achieve this critically important objective. Therefore, the current study sought to 1) determine the daily and cumulative workload for common ITPs using elbow varus torque (EVT), and 2) compare EVT experienced during completion of ITPs to game pitching EVT values.Methods:A retrospective review identified high school pitchers with at least 50 throws at distances of 90, 120, 150, and 180 feet plus game pitches while wearing a MotusBASEBALL sensor. Averages for EVT per throw and torque per minute were calculated at each distance. Three throwing programs were created using a template of one phase at each distance with two steps per phase (Table 1). Programs varied only by number of throws per set (20, 25, and 30 throws for Programs A, B, and C, respectively). Total EVT for each step, phase, and program were calculated using average EVT values for each distance. Total torque for each step and program was converted to an average inning pitched equivalent (IPE) and maximum pitch count equivalent (MPE), respectively, using pitching EVT values and expected average pitch counts (16 pitches/inning and maximum 105 pitches/game).Results:3,447 throws were analyzed from 7 pitchers with an average age of 16.7 yrs (0.8 yrs SD). EVT progressively increased with distance (range 36.9-45.5 N·m), comparable to game pitching (45.7 N·m). Average torque per minute was highest for 90 ft throws (193.4 N·m/min) and lowest for game pitches (125.0 N·m/min). Program A demonstrated the lowest range of IPE per step (2.0-3.7), and Program C had the highest range (3.0-5.6) (Figure 1). The phases of Program A never exceeded 1MPE. Program B exceeded this threshold after phase 1, and Program C exceeded 1MPE at every phase (Figure 2). Total program MPE ranged from 3.5 (Program A) to 5.2 (Program C).Conclusions:Performing long-toss throwing led to greater torque per minute compared to gameday pitching. Additionally, ITPs requiring 25 or more throws per set led to increased cumulative EVT, especially at distances greater than 150 ft, which can exceed typical values from gameday pitching. ITPs should be adjusted accordingly to encourage a slower pace of long-toss throws and less than 25 throws per set, especially at distances greater than 120 ft. Most ITPs currently recommend one rest day between steps. However, cumulative EVT at longer distances can exceed 5 IPE. Most pitch count rules require more than one rest day after a pitching outing that exceeds multiple innings pitched. Therefore, days off between steps and phases of an ITP should reflect these demands. We advocate for multiple days off between steps that require more than 3 IPE. Table 2 presents a novel ITP based on the findings of the current study.

Risk Factors for Throwing-Related Shoulder and Elbow Pain in Adolescent Baseball Players: A Prospective Study of Physical and Developmental Factors.

Background:Throwing-related shoulder and elbow pain continues to be reported among adolescent baseball players. Few prospective studies have specifically examined the association between throwing-related shoulder and elbow pain and physical and developmental changes.Purpose:To evaluate the changes in physical and developmental characteristics during 1 year with respect to throwing-related shoulder and elbow pain in adolescent baseball players.Study Design:Case-control study; Level of evidence, 3.Methods:This 1-year prospective follow-up study investigated 164 baseball players aged 7 to 13 years. Player data (age, height, weight, field position, and pitch count), lower extremity muscle tightness, and range of motion (ROM) of the shoulder, elbow, and hip joints were assessed during the 2016 and 2017 preseason medical examinations. After the 2016 season, the participants completed questionnaires related to throwing-related shoulder and elbow pain, defined as an inability to play for ≥1 week because of elbow or shoulder difficulties. For study participants with and without throwing-related shoulder or elbow pain during the 2016 season, we conducted univariate and multivariate logistic regression analysis to identify risk factors for throwing-related shoulder or elbow pain.Results:Overall, 21 players (12.8%) reported a shoulder pain episode, 56 players (34.1%) had an elbow pain episode, and 70 players (42.7%) reported having experienced shoulder and/or elbow pain during the 2016 season. In multivariate logistic regression analysis, (1) shoulder pain was associated with 2016 preseason height (odds ratio [OR], 1.06; 95% CI, 1.01-1.11; P = .01) and change in dominant-side elbow extension ROM from 2016 to 2017 (OR, 1.12; 95% CI, 1.02-1.24; P = .02); (2) elbow pain was associated with change in weight from 2016 to 2017 (OR, 1.21; 95% CI, 1.04-1.41; P = .014); and (3) throwing-related shoulder and/or elbow pain was associated with greater 2016 preseason height (OR, 1.04; 95% CI, 1.003-1.68; P = .03) and an increase in height from 2016 to 2017 (OR, 1.17; 95% CI, 1.01-1.35; P = .03).Conclusion:Our results indicated that adolescent baseball players who were taller in the preseason and those with an increase in height over the 1-year study period faced significant risks for developing throwing-related shoulder and/or elbow pain.

Decreased Shoulder and Elbow Joint Loads During the Changeup Compared With the Fastball and Curveball in NCAA Division I Collegiate Softball Pitchers.

Background:Baseball leagues have implemented pitch count and pitch type restrictions based on biomechanical concepts associated with pitch type. Softball has not yet adopted these practices, although softball pitchers continue to pitch at a high volume and learn multiple pitches at a young age.Purpose:To examine shoulder and elbow kinetics between the fastball, curveball, and changeup, as well as to provide descriptive upper extremity pain data in National Collegiate Athletic Association (NCAA) softball pitchers.Study Design:Descriptive laboratory study.Methods:Study participants consisted of 27 female NCAA Division I softball pitchers (age, 20.2 ± 1.9 years; height, 175.7 ± 5.7 cm; weight, 83.6 ± 12.7 kg). The participants pitched 3 balls of each pitch type, and kinetic data were recorded. A one-way within-participants repeated-measures multivariate analysis of variance was used to determine significant differences in kinetics and pitch speed between pitch types.Results:Results revealed a statistically significant main effect for pitch type (Wilks λ = .087; F = 36.523; P < .001). Post hoc testing showed that the changeup produced less anterior elbow force compared with the fastball (P < .001) and the curveball (P = .012). In addition, the changeup produced less shoulder distraction force compared with the fastball (P < .001) and the curveball (P = .001). Additionally, there was a significant difference in pitch speed between all 3 pitch types (P = .006). The curveball revealed no statistically significant kinetic differences compared with the fastball.Conclusion:The fastball and curveball placed similar stress on the upper extremity in collegiate softball pitchers. However, in comparison with the changeup, the fastball and curveball placed increased stress on the upper extremity. More research is needed to fully explain the differences seen between pitch type and injury risk.Clinical Relevance:Sports medicine professionals, coaches, and athletes should use the current study results to note these differences in shoulder distraction and elbow anterior forces between softball pitch types. The study results can be used as a reference and basis for future research investigating kinetic differences across varying pitch types.

Rest Day Requirements Have a Greater Effect on Season-Long Workload Expenditure by High School Pitchers than Pitch Count Limits: Implications for High School State Pitch Count Regulations

Objectives:High school baseball pitch count limits vary widely by state; however, it is unknown how these variations impact cumulative elbow varus torque (EVT) throughout a season. Specifically, pitch count limits are a popular method for preventing overuse in youth baseball players, but rest day requirements for different pitch count limits are often highly variable and less frequently analyzed. Therefore, the objectives of the current study were to (1) investigate variations in pitch count rules across all 50 states, (2) calculate maximum game, monthly and season-long EVT across all pitch count limits, and (3) calculate EVT across all pitch count limits after adjusting for rest days required by each state. We hypothesized that the number of required rest days based on gameday pitch count limits would lead to large variations in cumulative EVT workload over the course of a season.Methods:Pitch count allowances and required rest days for high school baseball pitchers were recorded from the athletic association website of each state. The Motus Global database was queried for all high school pitchers. Average EVT for game pitches was quantified and used to calculate cumulative game, weekly, monthly, and season EVT during a projected 3-month season for each maximum pitch count limit assuming a three-day rest period. Values were subsequently recalculated for each group of states based on pitch count allowances and actual required rest days.Results:The Motus Global database provided 65,928 pitches from 45 high school pitchers with an average age of 16.9 ± 0.8 years. Average EVT per pitch was 45.04 ± 10.46 N•m. High school baseball is not a sanctioned sport in 2 states (Montana and Wyoming), leaving 48 states for analysis. The most common midseason maximum pitch count limit was 110 pitches (19 states, range 100-125 pitches), and the most common required rest days was 4 days (24 states, range 0-5 days) (Table 1). Assuming three-days rest between maximum pitch outings, there was a 20% difference in cumulative EVT during a season between 100 and 125 maximum pitches. When maximum pitch counts were projected with required rest days, allowing a maximum of 140 pitches in a 4 day span without a specific rest day requirement resulted in the most EVT during a season (Nevada), followed by allowing a maximum pitch count of 125 pitches with a rest requirement of 3 days (Louisiana/Ohio, Figure 1). Pennsylvania and Wisconsin allowed the least amount of pitches (i.e. 100 pitches) with the shortest required rest days (i.e. 3 days), resulting in the lowest EVT for a game and week but the sixth highest season EVT. Conversely, South Carolina allowed 110 pitches but required the most rest days (5 days), resulting in the lowest season EVT. Overall, there was a 48.8% difference in EVT during a season between the most and least restrictive states. A greater seasonal EVT in the lowest pitch count range with 1 required rest day compared to the highest pitch range was observed in 28 states (58%). Average seasonal workload of every pitch count range per required rest days for all states is summarized in Figure 2. This generally demonstrates an inverse trend with a 30% greater EVT differential between the lowest pitch range with one required rest day and the highest pitch range with 5 required rest days. Only 1 state had equal seasonal EVT at both maximum and minimal pitch ranges (Pennsylvania).Conclusions:There is wide variability in pitch count rules between states. Required rest days are often an underappreciated aspect of pitch count rules, yet they may influence season-long EVT more than maximum pitch count allowances. For example, the maximal seasonal EVT did not occur at maximal pitch limits for the majority of states. Instead, it most frequently occurred at the lowest pitch count allowance with 1 rest day (58% of states). A primary example is Indiana, which has a 20% greater potential seasonal EVT in the lowest pitch range (36-60 pitches, 1 rest day requirement) compared to its maximal pitch limit (101-120 pitches, 4 rest day requirement). Pitch count rules should be analyzed to ensure that projected workload across all pitch count and rest day allowances are proportional. Therefore, standardization of pitch count rules across states should be considered with increased emphasis on rest day restrictions.

PITCHING IN YOUTH SOFTBALL: HOW MUCH ARE PITCHERS THROWING?

Background:Softball is a popular sport among youth female athletes. While multiple youth baseball studies have evaluated the relationship of injury to pitch counts, there is a paucity of literature for youth softball. In contrast to the numerous youth baseball leagues adhering to pitching guidelines, pitch counts are frequently not enforced in youth softball which results in pitchers with exceedingly high volumes.Purpose:The purpose of this study was to perform a quantitative analysis of pitching volume in youth softball players. We hypothesized that the majority of pitches would be thrown by a small proportion of pitchers on each team.Methods:Seventy youth softball teams including 538 pitchers competing in age brackets eight and under (8U) to fourteen and under (14U) between Spring 2017 and Fall 2019. Game dates and pitch counts were collected for each player using an electronic application. Games played on two or more consecutive days were defined as a tournament. The three highest-volume pitchers from each team defined by total season pitches were analyzed for comparison to the average pitcher.Results:538 pitchers on 70 teams were included. The average pitcher threw 813 pitches per year and appeared in 20.0% of games and the average high-volume pitcher threw 2500 pitches per year and appeared in 54.5% of games. The highest-volume pitcher from each team threw 40% of all recorded pitches, the second highest 27.2%, and the third highest 15.2%, totaling 82.4% of all team pitches. Single day pitch counts of >100 and >200 occurred in 17.7%, and 1.1% of same day games with the average pitcher and in 31.2%, and 2.4% of same day games with the average highest-volume pitcher. Tournament pitch counts of >100 and >200 occurred in 51.0% and 13.8% of tournaments with the average pitcher and in 81.4% and 30.8% of tournaments with the average highest-volume pitcher. The average and highest-volume pitcher threw pitches in two or more games on the same day in 37.5% and 48.6% of possible games while pitching two or more consecutive days in 64.0% and 79.6% of possible games, respectively.Conclusion:Softball pitchers throw high volumes of pitches while also pitching multiple days consecutively. A disparity among pitchers on softball teams exists as 82.4% of team pitches are thrown by three pitchers. These high-volume pitchers may be engaging in unsustainable pitching practices that could predispose to injury.Tables:

Adolescent Pitcher Fatigue: Ulnar Collateral Ligament Stress, Flexor-Pronator Mass Energy Depletion, and Correlation to Pitch Count

Objectives:There has been a rise in elbow ulnar collateral ligament (UCL) injuries in youth pitchers over recent years. With forearm flexor-pronator mass fatigue, the dynamic stability provided could be diminished placing greater stress on the UCL. Pitch count limits have been instituted in an attempt to help curtail this rise in throwing injuries, especially in youth athletes. In order to provide more objective data regarding current pitch count limits for youth pitchers, the purpose of this pilot study was to evaluate for potential fatigue of the flexor-pronator mass by assessing changes in medial elbow laxity, noninvasively characterizing changes in muscle glycogen storage within the forearm flexor-pronator mass, and evaluating changes in subjective fatigue, strength, range of motion (ROM), pitching velocity, and accuracy with increasing number of pitches thrown by 10-year-old pitchers up to their recommended 75 pitch count limit.Methods:After appropriate power analysis, male pitchers 10 years of age were recruited for the study (n=22). Pitchers threw a total of 75 pitches divided into sets of 25 pitches, with standardized periods of rest in between throws and sets to best simulate a game. Bilateral medial elbow laxity was measured by applying 10 decanewtons of valgus force with a standardized stress device and utilizing ultrasound imaging (Figures 1A-B) prior to pitching and after each pitching set. The change in medial ulnohumeral joint distance (Figure 1C) after stress was applied was calculated from baseline without stress. Relative changes in muscle glycogen storage, detected as changes in echogenicity, within the flexor carpi radialis (FCR) and the flexor digitorum superficialis (FDS)/flexor carpi ulnaris (FCU) muscles were measured non-invasively with ultrasound-based software (Figures 1D-E) and recorded as fuel percentile. Repeated measures analysis of variance and post-hoc testing were used to determine statistical significance (alpha=0.05).Results:There were no significant differences in medial elbow laxity between arms or time points. There was a trend for similar decline in FCR fuel percentile values between each arm, indicating relative decreases in glycogen storage bilaterally. However, only the throwing arm demonstrated a statistically significant decline in fuel percentile from baseline to after 75 pitches (p=0.05). There were no statistically significant differences across time points for FDS/FCU fuel percentile values. Fatigue measurements for both arms were significantly higher at all time points compared to baseline (p≤0.03). Grip strength of the dominant arm after 75 pitches was significantly decreased compared to after 25 pitches (p=0.02). There were no statistically significant changes in other strength measurements, ROM, velocity, or accuracy between all time points.Conclusions:By the recommended 75 pitch count limit in 10-year-olds, subjective fatigue and a decrease in grip strength had occurred. Furthermore, relative glycogen storage of the flexor-pronator mass of the throwing arm decreased between pitching 50 to 75 pitches, but without an increase in medial elbow gapping. This study provides a foundation and raises questions for further objective testing of physiologic changes that occur throughout increasing pitching to better guide pitch count limits and ensure the safety of young athletes

Limiting the Pitch Count in Youth Baseball Pitchers Decreases Elbow Pain.

Background:Reducing the number of pitches thrown is regarded as the most effective way to prevent throwing injuries in youth baseball pitchers. However, few studies have compared the effectiveness of limiting the pitch count versus the limiting the number of innings pitched in terms of elbow injuries.Hypothesis:We hypothesized that, compared with inning limits, pitch count limits would lead to greater decreases in elbow pain, range of motion deficits, positive moving valgus stress test results, and the risk of capitellar osteochondritis dissecans (OCD).Study Design:Cohort study; Level of evidence, 3.Methods:This study retrospectively reviewed baseball pitchers aged 8 to 12 years in 2017 and 2018. Inning and pitch count limits in games were set to a daily maximum of 7 innings in 2017 and 70 pitches in 2018. Elbow pain, range of motion, and moving valgus stress test results were evaluated. The presence of capitellar OCD was assessed on ultrasonographic and radiographic images.Results:A total of 352 pitchers in 2017 and 367 pitchers in 2018 participated. The mean pitch count per game was lower in the pitch count limit (CL) group (52.5 ± 16.0) than in the inning limit (IL) group (98.2 ± 19.5) (P < .001). Compared with the IL group, the CL group had significantly lower rates of elbow pain (40.9% vs 31.9%, respectively; P = .01) and reduced flexion (19.0% vs 10.6%, respectively; P = .001). Multivariate analysis revealed a significant association between elbow pain and age in both the IL and the CL groups (P < .0001 and P = .02, respectively) and between OCD and elbow pain in the CL group (P = .04).Conclusion:A pitch count limit of ≤70 pitches per day for baseball pitchers ≤12 years could be more protective against elbow pain and reduced flexion than a limit of ≤7 innings per day, but it may not be effective for reducing the risk of capitellar OCD.

Immediate Changes and Recovery of the Supraspinatus, Long Head Biceps Tendon, and Range of Motion after Pitching in Youth Baseball Players: How Much Rest Is Needed after Pitching? Sonoelastography on the Supraspinatus Muscle-Tendon and Biceps Long Head Tendon.

BackgroudBaseball players are subjected to repeated loads on the supraspinatus and long head biceps tendon from youth, and repetitive pitching motions can cause shoulder injuries. The purpose of this study was to evaluate the immediate changes caused by pitching in the supraspinatus muscle-tendon, long head of the bicep tendon (LHBT), and shoulder range of motion (ROM) and to verify their recovery over time in youth baseball players.MethodsFifteen youth baseball players (mean age, 11.5 ± 1.3 years) were enrolled. The thicknesses of the supraspinatus tendon and LHBT and the strain ratios (SRs) of supraspinatus muscle and tendon were measured by sonoelastography. ROMs of shoulder joints (abduction, external rotation at 90° of abduction [ABER], and internal rotations at 90° of abduction [ABIR]) and horizontal adduction (HA) were measured using a goniometer. All measurements were performed on the throwing shoulders before and immediately after pitching (mean pitch count, 78.3 ± 13.3) and at 30 minutes, 24 hours, and 72 hours after pitching.ResultsThe thickness of supraspinatus tendon (6.64–6.27 mm, p = 0.026) and that of LHBT (2.56–2.26 mm, p = 0.021) significantly decreased immediately after pitching. The SRs of supraspinatus muscle tended to decrease, whereas SRs of supraspinatus tendon tended to increase immediately after pitching. ABER increased (119.7°–127.3°, p = 0.001) and HA decreased (34.7°–29.3°, p = 0.023) immediately after pitching. All immediate changes recovered 72 hours after pitching.ConclusionsThe immediate effects of pitching on the supraspinatus muscle-tendon, LHBT, and shoulder ROM in youth baseball players were confirmed in the current study. These changes were recovered to pre-pitch levels 72 hours after pitching. Therefore, we recommend that youth baseball players should rest for three days after pitching to minimize the risk of shoulder injury.

Limiting the Pitch Count in Youth Baseball Pitchers

Limiting the Pitch Count in Youth Baseball Pitchers

Biceps Tendon Changes and Pitching Mechanics in Youth Softball Pitchers.

With the lack of pitch count regulation, youth softball pitchers are experiencing unremitting high stresses on the anterior shoulder. The purpose of this study was to examine the association of acute changes in the long head of the biceps tendon with pitching kinematics and kinetics in youth softball pitchers following an acute bout of pitching. Twenty-three softball pitchers (12.17±1.50 yrs.; 160.32±9.41 cm; 60.40±15.97 kg) participated. To investigate the association between biceps tendon changes and kinematic and kinetic changes from pre- to post-simulated game, each biceps tendon measure was split into those whose biceps tendon thickness, width, and/or area increased pre- to post-simulated game, and those whose did not. There were significant differences in biceps tendon longitudinal thickness (Z=- 2.739, p=0.006) and pitch speed; as well as a difference between groups in biceps tendon transverse thickness and the amount of change in trunk rotation at the start of the pitching motion (p=0.017) and the amount of change in trunk flexion at ball release (p=0.030). This study illustrates the association of trunk and lower extremity kinematics and shoulder kinetics with morphologic changes in the biceps tendon with an acute bout of windmill softball pitching.

Accelerated Muscle Recovery in Baseball Pitchers Using Phase Change Material Cooling.

The purpose of this study was to document recovery after a pitching performance and determine whether prolonged postgame phase change material (PCM) cooling of the shoulder and forearm accelerates recovery. Strength, soreness, and serum creatine kinase (CK) activity were assessed before and on the 2 d after pitching performances in 16 college pitchers. Pitchers were randomized to receive either postgame PCM cooling packs on the shoulder and forearm or no cooling (control). PCM packs were applied inside compression shirts and delivered cooling at a constant temperature of 15°C for 3 h. Strength was assessed for shoulder internal rotation (IR), external rotation (ER), empty can (EC) test, and grip. Total pitch count was 60 ± 16 for 23 PCM cooling games and 62 ± 17 for 24 control games (P = 0.679). On the days after pitching, IR strength (P = 0.006) and grip strength (P = 0.036) were higher in the PCM cooling group versus control. One day after pitching, IR strength was 95% ± 14% of baseline with PCM cooling versus 83% ± 13% for control (P = 0.008, effect size d = 0.91) and 107% ± 9% versus 95% ± 10% for grip strength (P = 0.022, effect size d = 1.29). There was a trend for greater ER strength with PCM cooling (P = 0.091, effect size d = 0.51). The EC strength was not impaired after pitching (P = 0.147) and was therefore unaffected by PCM cooling (P = 0.168). Elevations in soreness and CK were not different between treatments (treatment-time CK P = 0.139, shoulder soreness P = 0.885, forearm soreness P = 0.206). This is one of the first studies to document impairments in muscle function on the days after baseball pitching, and the first study showing a novel cryotherapy intervention that accelerates recovery of muscle function in baseball pitchers after a game.

Lower Extremity Strength and Recovery Time in Youth Baseball Pitchers: A Pilot Study.

Livingston, JL and Tavoukjian, NM. Lower extremity strength and recovery time in youth baseball pitchers: a pilot study. J Strength Cond Res 34(7): 1990-1998, 2020-The purpose of this study was to investigate the Little League pitching regulations by measuring the change in lower extremity force production after a pitching performance and the subsequent days of rest required for youth baseball pitchers to recover. Bilateral manual muscle testing of the gluteus maximus, hamstrings, gluteus medius, triceps surae, and quadriceps was conducted using a handheld dynamometer. Fifteen healthy, youth baseball pitchers (9.80 ± 1.08 years) threw a submaximal number of pitches and were tested before, immediately after, and for the next 4 consecutive days. Time in days required per muscle group to return to baseline force production levels were compared with Little League rest guidelines for pitchers. Results indicated that Little League rest requirements did not allow for sufficient recovery of lower extremity strength (p = 0.017). Results suggest that current Little League pitching guidelines provide an inadequate recovery period for youth pitchers, even when pitching a submaximal volume. Little League pitch count regulations and associated rest days may require revisions to avoid having youth athletes pitch while fatigued.

Quantification Of On-ice Figure Skating Jumps Using Data From A Wearable Device

The number of jumps figure skaters perform daily has never been formally quantified, though it has been suggested that skaters perform 50-100 jumps per training day. The magnitude of force, high loading rates, and frequent repetitions likely contribute to the high injury rate of competitive skaters. Monitoring the number of jumps performed may help decrease risk of injury, similar to the institution of pitch counts in youth baseball. Activity monitors that are commonly used for activities such as walking and running record many false positives during figure skating jump quantification due to the variety of skating movements that generate similar acceleration profiles. Previously, we developed an algorithm that successfully counted 39 of 40 jumps performed during the competitive routines of 7 local skaters whose isolated jumps were used to create the algorithm. PURPOSE: To test the performance of the algorithm on an independent sample of skaters of varying skill levels. METHODS: 18 healthy competitive figure skaters participated in this study (ages 8-26y, 12 female). Each skater wore an IMU affixed to the lower back while they performed a variety of jumps, spins, and footwork. A high speed video camera recorded all trials for validation purposes. Custom software was used to analyze the IMU data to quantify the number of jumps performed with >1 rotation. RESULTS: Analysis of the videos showed that we recorded a total of 200 jumps with >1 rotation. The algorithm correctly quantified 94.5% of the jumps in this dataset (189 successful jumps). It also identified 11 jumps with ≤1 rotation. CONCLUSIONS: These results show that this algorithm can be successfully applied to a unique dataset. Many of the jumps with ≤1 rotation that were counted were “popped” jumps, where a skater intends to perform a multi-revolution jump prior to take-off, but perform a single instead. Multi-revolution jumps that were not counted included falls and those with too much rotation that occurs on the ice prior to take-off. Finally, this dataset showed that the algorithm may need to be customized for smaller and/or low-level skaters as it failed to identify 7 of 12 jumps performed by a small, beginning level skater (8y, 122cm, 23.6 kg). Further improvements may be made by using machine learning algorithms to differentiate types of jumps as well as jump count.

PITCH COUNTS IN YOUTH BASEBALL PLAYERS: A COMPARISON TO PITCH SMART GUIDELINES

Background:Overthrowing injuries in youth baseball players have been linked with pitching behaviors such as as high pitch counts, inadequate rest, and participating in throwing activities throughout the year. Pitch Smart guidelines were developed as an initiative between Major League Baseball and USA Baseball to provide recommendations for youth baseball athletes to help decrease the risk of injuries from overthrowing.Purpose:The purpose of this study was to perform a quantitative analysis of pitch counts in youth baseball players and evaluate compliance with Pitch Smart guidelines.Methods:Local youth baseball teams competing in nine and under (9U) to fourteen and under (14U) age brackets were recruited to track pitches during the summer baseball season. A tablet with a pitch counting application was used to record pitches for each pitcher of the study team and their opponents. Days of rest between games was calculated for the study teams only and not opponents. Pitch counts and days of rest for each pitcher were compared to the recommended Pitch Smart guidelines. Continued prospective collection of data is ongoing through the 2019 summer.Results:Interim review of 23 youth baseball teams using a tablet allowed analysis of 181 pitchers of the 23 study teams using tablets and 285 pitchers of 98 opponent teams. Violation of Pitch Smart guidelines occurred in 14 (60.9%) study teams and 29 (16.0%) pitchers. Of these violations, 27 (93%) pitchers had insufficient rest between games while 2 (7%) pitchers exceeded daily maximum pitches. Further, 8 (35%) teams had more than one player violate guidelines. Pitch smart daily maximum pitch counts were violated in 2 of 98 (2.0%) opponent teams and 2 of 285 (0.7%) of opponent pitchersConclusion:A total of 61% of youth baseball teams and 16% of pitchers in this study violated Pitch Smart guidelines at interim analysis. The vast majority of guideline violations were due to inadequate rest between games. The high rate of Pitch Smart violations suggests that further education of coaches, parents, and athletes regarding these guidelines, with emphasis on rest recommendations, is necessary to prevent overthrowing injuries in youth baseball players.Table:.Age Group# Study Team Violations# Study Pitcher Violations (Rest)# Study Pitcher Violations (Daily Max)# Opponent Team Violations# Opponent Pitcher Violations (Daily Max)9U5 / 6 (83%)10 / 52 (19%)1 / 52 (2%)1 / 20 (5%)1 / 58 (2%)10U4 / 5 (80%)10 / 42 (24%)0 / 42 (0%)0 / 30 (0%)0 / 101 (0%)11U0 / 0 (0%)0 / 0 (0%)0 / 0 (0%)0 / 0 (0%)0 / 0 (0%)12U0 / 3 (0%)0 / 21 (0%)0 / 21 (0%)0 / 7 (0%)0 / 18 (0%)13U5 / 8 (63%)7 / 60 (12%)1 / 60 (2%)0 / 32 (0%)0 / 87 (0%)14U0 / 1 (0%)0 / 6 (0%)0 / 6 (0%)1 / 9 (11%)1 / 21 (5%) 14 / 23 (60.9%)27 / 181 (14.9%)2 / 181 (1.1%)2 / 98 (2.0%)2 / 285 (0.7%)

EFFECTS OF A SIMULATED GAME ON PITCHING KINEMATICS IN YOUTH FEMALE SOFTBALL PITCHERS

Background:Despite evidence that overuse is the most common mechanism of injury, softball pitchers currently have no pitch count regulations. Pain has been associated with certain pitching pathomechanics, and some reports indicate increased pain following a single pitching bout.Hypothesis/Purpose:The purpose of this study was to analyze kinematic variables such as center of mass (COM), trunk, and stride length during the first and last inning of a simulated game in youth softball pitchers. We hypothesized COM to be shifted back toward the drive leg, stride length would be increased, and trunk kinematics would be altered during the last inning of a simulated game as compared to the first inning.Methods:Participants included thirty-two softball pitchers (12.4±1.6yrs., 159.4±8.9cm, 62.0±13.6kg). Participants were deemed injury and surgery free for the past six months and were currently active as a pitcher on their teams’ roster. Kinematic data were collected at 100Hz using an electromagnetic system. After warm-up, participants were instructed to throw random game situations, provided by the investigator, with the catcher located at regulation distance (43ft). Participants were required to produce three outs an inning as per a regulation softball game. Three fastballs from the first and last inning were recorded and used for analysis. Kinematics were analyzed at five different pitch events including: start of pitch, top of pitch, foot contact, ball release, and follow through.Results:A paired samples t-test revealed a statistically significant difference in trunk rotation during the first three pitching events from the first and last inning. Specifically, pitchers exhibited less trunk rotation towards the pitching arm side. A bivariate Pearson’s correlation showed volume of pitches was correlated with stride length (r=.367, p=.039) and COM (r=.364, p=.041) at the start of the pitch, and trunk flexion at top of pitch (r=-.392, p=.026), foot contact (r=-.413, p=.019), and follow-through (r=-.436, p=.013).Conclusion/Significance:Trunk kinematics, stride length, and COM were altered as pitch volume increased. These results provide clinical importance as the trunk pathomechanics seen may be indicative of poor trunk control and fatigue. Although it is out of the realm of this study to state whether the kinematic changes seen are associated with injury, we do know that deficits in the kinetic chain are associated with injury and that trunk pathomechanics are associated with pain in collegiate softball pitchers. Research should continue to investigate the effects of pitch count, pitch mechanics, and injury in youth softball pitchers.

The Pitching Problem: Proxy Measures for the Identification of Pitcher Fatigue

ObjectiveThis study assessed the utilization of accessible records and metrics in developing proxy measures for fatigue in professional starting pitchers, and to understand the associated effects within lapses in short‐term and long‐term performance.Design and MethodsLeveraging MLB Statcast AI, we pulled relevant data relating to pitches thrown during the 2015 – 2018 regular and postseasons. The available data was then analyzed in three separate iterations to better understand and isolate the impact of critical metrics. This iterative approach isolated the data based on the following subcategories: anecdotal game, seasonal, and aggregate sets.ResultsThrough the prior detailed approach, we established the significance of three unaccounted for workload factors that represented suitable proxies for the identification of fatigue in starting pitchers. These factors included: strike‐to‐ball ratio, rest period, and a hit‐to‐strike ratio. These metrics represent a means of analyzing fatigue in relation to a pitcher’s performance through the course of a single game, and subsequently, inform optimal strategies as to bullpen management.ConclusionsAs a starting pitcher approaches a pitch count of thirty, management staffs can begin to utilize the prior mentioned proxy metrics as indicators of the impact of fatigue on a pitcher’s performance. These measures represent an alternative to traditional methods and an accessible solution.

What Can a Jump Tell Us About Elbow Injuries in Professional Baseball Pitchers?

Background: The incidence rate of elbow injuries has been rising in recent years among professional baseball pitchers. Determining valid screening procedures that allow practitioners to identify pitchers at an increased risk of such injuries is therefore of critical importance. Purpose: To validate the use of countermovement jump (CMJ) tests as a diagnostic tool for pitcher conditioning. Study Design: Case-control study; Level of evidence, 3. Methods: More than 500 pitchers at a single professional baseball organization performed preseason CMJ assessments on a force plate before the 2013 to 2018 seasons. Three measurements were extracted from ground-reaction force data during the test: eccentric rate of force development (ERFD), average vertical concentric force (AVCF), and concentric vertical impulse (CVI). Athletic trainers at the organization collected detailed information on elbow and shoulder injury rates as well as workload (pitch count) throughout the rest of the season. Poisson regression models were fit to investigate the dependency of injury rates on CMJ test performance. Results: ERFD, CVI, and AVCF were all significant predictors of elbow injury risk after accounting for pitcher age, weight, and workload. The analysis identified 3 specific indicators of heightened risk based on the results of a CMJ scan: low ERFD, a combination of low AVCF and high CVI, and a combination of high AVCF and low CVI. In contrast, shoulder injury risk was roughly independent of all 3 CMJ test measurements. Conclusion: This study supports the hypothesis of the entire kinetic chain’s involvement in pitching by establishing a link between CMJ test performance and elbow injury risk in professional baseball pitchers. CMJ assessment may be a powerful addition to injury risk alert and prevention protocols. Pitchers in high-risk groups can be prescribed specific exercise plans to improve movement imbalances.

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

The primary purpose of this study was to compare the number of pitches thrown by youth baseball players under the official league guidelines versus the number of "high-effort" throws recorded by a validated digital sensor worn by the players during a season. In total, 11 and 12-year-old youth baseball players from a single league were provided an elbow sleeve and sensor to wear each time they threw a baseball for an entire baseball season. The sensor tracked total throws and pitch-equivalent high-effort throws for the season. Official pitch counts were collected at each game from the official scorekeepers. A total of 19 players participated in the study. The sensor-determined mean total throw count (1666.2±642.2) and mean high-effort throw count (576.9±329.3) per player were both significantly higher, P<0.0001 and P=0.02, respectively, than the mean official pitch count (168.1±122.4). Our findings demonstrate that youth players make significantly more total throws and high-effort, or pitch-equivalent, throws, than what is recorded by the official pitch counts. Further research is needed to determine a safe annual "throw count" for young throwing athletes and to determine which types of throws, in addition to pitches, put youth throwers at risk for injury. Level IV.