Professional Baseball Players Research Articles

Effect of Weather and Game Factors on Injury Rates in Professional Baseball Players

Background: Injury rates in baseball players of all ages are increasing. Identifying modifiable risk factors is paramount to implementing injury prevention programs. Purpose/Hypothesis: The purpose was to evaluate the influence of weather (temperature, humidity, atmospheric pressure, and heat index) and game factors (start time, duration, single vs doubleheader) on injury rates in professional baseball players. We hypothesized that colder temperatures would be associated with significantly more injuries per game. Study Design: Case-control study; Level of evidence, 3. Methods: This was a retrospective database study. Two data sets were combined: 1 containing all injuries in Major and Minor League Baseball between 2011 and 2017 and 1 containing all games played in Major and Minor League Baseball during the same period to determine the number of injuries per game. Temperature, humidity, atmospheric pressure, and heat index were determined for each game using the data from the US Environmental Protection Agency. Additional game variables included the level of play, the turf type (natural vs artificial grass), the stadium type (open vs dome vs retractable), the game start time, the game duration, and whether the game was a doubleheader. Then, a multivariate analysis was conducted to determine which factors were associated with the number of injuries per game. Results: In total, our analysis included 33,587 injuries and 76,747 games. A total of 25,776 (33.6%) games contained an injury, and 41% of injuries occurred as multiples per game, with up to 9 injuries per game. The multivariate analysis identified significant associations between game duration and injuries per game (P < .001; effect size, 0.013) and the level of play and injuries per game (P < .001; effect size, 0.011). There were significant associations between the venue type (P < .001), the game start time (P < .001), humidity (P < .001), the turf type (P = .016), and barometric pressure (P = .031); however, the effect size for each was <0.001, suggesting that these factors are clinically unimportant. Our overall model produced an R2 of 0.04, indicating that these variables only predicted 4% of the variance in injury risk. Conclusion: In professional baseball, the weather is not associated with injury risk; however, game duration may contribute to injury risk.

Cryoneurolysis for Digital Neuralgia in Professional Baseball Players: A Case Series

We describe a non-surgical approach to refractory digital neuralgia using cryoneurolysis in a series of 3 professional baseball players. Thumb injuries are common in baseball players and can sometimes be challenging to effectively manage. Depending on the injury, current treatments include anti-inflammatories, immobilization, physical therapy, corticosteroid injections, and/or surgery. A subset of patients, however, fail nonoperative management yet do not have a clear indication for surgery. Cryoneurolysis or cyroanalgesia is an FDA-approved form of neuromodulation, which has been used safely and effectively on a variety of peripheral nerves. The mechanism of action involves percutaneous introduction of a small probe under local anesthetic to nerve tissue using ultrasound guidance. The probe is then cooled to -88°C using nitrous oxide, which results in secondary Wallerian degeneration. Axonal and myelin regeneration occurs completely in 3-6 months. Visualization of the superficial radial sensory and ulnar digital nerve were obtained under ultrasound. The skin was prepared in sterile fashion. A 22-gauge 1-½ inch needle was then advanced with ultrasound guidance, and local anesthetic was applied. Both treatment sites were marked with skin marker. Cryoneurolysis was employed using a 5 mm tip. 60-second treatment cycles were performed at each site. Each of the cycles resulted in a 5 × 7 mm lesion visible as hypoechoic signal. All 3 players endorsed significant and prolonged relief and were able to return to an elite level of play. This manuscript is subject to all of the limitations of a case series, and larger rigorous studies are needed to illuminate causal inferences. Novel, complex technologies may also be more susceptible to placebo effect. Nonetheless, we are able to report marked efficacy and safety from cryoneurolysis of the ulnar digital nerve and the superficial radial sensory nerve in a small group of elite baseball players with refractory digital neuralgia.

How does the All-Star break affect injury rates in professional baseball?

Injury rates in professional baseball players are increasing. It is unclear if the time of rest from the All-Star break affects injury risk. Every professional baseball game (A-, A+, AA, AAA, and Major League Baseball) played between 2011 and 2017 was included. Each game was then classified as control game (games played in April, May, June, and September) or game within one month after the All-Star break. Incidence of injuries in games within one month of the All-Star break was compared with the control games. Our analysis included 66,642 games: 46,630 control games and 20,012 games played within one month after the All-Star break. On univariate analysis, there was a mean ± standard deviation of 0.45 ± 0.72 injuries per game in control games and 0.41 ± 0.68 injuries per game in games played within one month after the All-Star break (P<.001). On multivariate analysis, there was a significant association between games played within one month after the All-Star break and number of injuries per game (P<.001) after adjusting for the level of play and game duration. However, the effect size was 0.001, suggesting this effect is clinically insignificant. There does not appear to be a clinically significant difference in injury rates per game in professional baseball players between games played in the month after the All-Star break and all other games played during the season. Although the All-Star break provides most players with a chance to rest, it does not appear to have an effect on injury rates.

Comparison of Glenohumeral Range of Motion Deficits in Youth, Collegiate, and Professional Baseball Players.

BackgroundExamining range of motion deficits across levels of baseball competition can result in a better understanding of the extent of altered range of motion patterns and identify competition levels that may require preventative interventions that target the deficits.PurposeThe purpose of this study was to compare shoulder range of motion in baseball players across levels of competition and compare the prevalence of glenohumeral internal rotaton deficit (GIRD) and total arc of motion differences (TAMD) between competition levels in pitchers and position players.Study DesignProspective descriptive cohortMethodsPassive internal and external rotation range of motion was measured bilaterally. Individuals with current pain in the arm, shoulder, elbow or shoulder surgery within the prior two years were excluded. Measurements were taken during pre-season physical examinations. Players were divided into seven groups: 12u (11-12 years; n=30), 14u (13-14 years; n=30), High School 1 (HS 1; 15-16 year; n=42), High School 2 (HS 2; 17-18 years; n=25), College (n=22), Professional 1 (Pro1; 17-22 years; n=37) and Professional 2 (Pro2; 23 and older; n=37). Multiple one-way analyses of variance were performed to determine differences between groups. Tukey test for post-hoc analysis was employed to determine which competition levels were significantly different.ResultsTwo-hundred and twenty-three male baseball players ages 11-26 participated. The 12u (53.7°) and 14u (54.2°) groups had significantly less internal rotation than HS1 (65.2°), HS2 (63.9°), College (62.3°), Pro1 (64.9°), and Pro2 (64.5°) players (p<0.0001). The 12u, 14u, HS1, college, and Pro2 groups had greater than 50% of players with total arc of motion differences >5°. Conclusions: Range of motion alterations exist across ages and levels of competition with 12u and 14u players having less internal rotation than the older groups and youth pitchers having less total range of motion than HS1.Level of Evidence2

Health Conditions, Substance Use, Physical Activity, and Quality of Life in Current and Former Baseball Players.

Background:A comprehensive understanding of lifestyle (health conditions and substance use), health-related quality of life (HRQoL), flourishing (holistic representation of health), and physical activity can inform stakeholders (players, coaches, and clinicians) and help improve long-term health across the life span.Purpose:To describe health conditions (comorbidities or diagnoses), substance use, physical activity, HRQoL, and flourishing in current and former collegiate and professional baseball players and to assess the relationship between playing position and HRQoL/flourishing in former baseball players.Study Design:Descriptive epidemiology study.Methods:Eligible participants were those ≥18 years old with ≥1 season of collegiate or professional baseball experience. Participants completed a survey on health conditions (asthma, diabetes, hypertension, hypercholesterolemia, and depression), substance use (tobacco, alcohol, and energy drinks), physical activity (International Physical Activity Questionnaire–Short Form), HRQoL (Veterans Rand 12-Item Health Survey [VR-12] physical and mental component scores), and flourishing (Flourishing Scale). Adjusted multivariable regressions were performed for HRQoL and flourishing.Results:Overall, 260 baseball players opened the survey, and 214 (current players, 97; former players, 117) participated for an 82% response rate. Of the former players, 32% had hypertension or hypercholesterolemia. In addition, 26% of current players had used smokeless tobacco (median, 3 years; interquartile range [IQR], 1-5 years) as compared with 34% of former players (median, 15 years; IQR, 5-25 years). In addition, 14% of current players had used electronic cigarettes (median, 2 years; IQR, 0-4 years) as opposed to 3% of former (median, 3 years; IQR, 2-4 years). Energy drinks were consumed by 31% and 14%, respectively, of current and former players on at least a weekly basis. Current baseball players performed 8667 metabolic equivalents per week of physical activity as opposed to 3931 in former players. Pitching was associated with worse VR-12 Mental Component Scores (–5.0; 95% confidence interval, –9.0 to –1.0). Playing position was not related to VR-12 Physical Component Scores or flourishing in former baseball players.Conclusion:The similar smokeless tobacco prevalence between current and former baseball players suggests that they may start using tobacco products during baseball participation and continue after retirement. Similar reported HRQoL as compared with the general US population and high flourishing and physical activity levels suggest that baseball players may present with good musculoskeletal and psychological health.

Union Activism and the Baseball Hall of Fame Voting Process: Labor-Management Conflict and Media Bias

Media bias is well documented in the industrial relations domain. This paper extends this research by exploring whether union participation among former professional baseball players affects the likelihood of moving through two stages of the selection process for the Major League Baseball Hall of Fame (HOF), a selection process controlled by sports media. At the HOF ballot inclusion stage, union activism increased position players’ and pitchers’ likelihoods of inclusion, regardless of time period. Conversely, at the HOF voting stage, position players who were union representatives during labor-management conflict (i.e., strikes and lockouts) received significantly less votes than non-activists, while position players who were representatives during labor-management cooperation received significantly more votes. Union activism did not affect pitchers at this stage. We conclude that union activists can be subject to negative media bias during labor-management conflict that, in turn, negatively affects post-employment outcomes.

Do Injury Rates in Position Players Who Convert to Pitchers in Professional Baseball Differ From Players Who Have Always Been Pitchers?

Background:There are some professional baseball players who begin their career as a position player and later convert to a pitcher; injury rates in these players are unknown.Purpose:To compare injury rates of professional baseball players who started their career as position players and converted to pitchers with a control group of pitchers who have been only pitchers throughout their professional career.Hypothesis:Injury rates would be lower in the conversion players.Study Design:Cohort study; Level of evidence, 3.Methods:All players who began their professional baseball career as position players and converted to pitchers between 2011 and 2018 were included. All injuries that occurred after they converted to pitchers were included. The conversion players were matched 1 to 1 with a control group of pitchers who entered professional baseball as pitchers and never changed position. Injury rates were compared between groups. The performance between groups was also compared.Results:Overall, 221 players were identified who converted from position players to pitchers. There were significantly more injuries per year in the control pitcher group (0.8 ± 0.9) than in the conversion pitcher group (0.7 ± 0.9; P = .015). Injuries in the control group resulted in 61 ± 112 days missed per injury, while injuries in the conversion player group resulted in 54 ± 102 days missed per injury (P = .894). Injury characteristics differed between groups. However, in both groups, most of the injuries were related to pitching or throwing, were noncontact or gradual overuse injuries, and involved the upper extremity. Converted pitchers had lower pitcher usage, with fewer games and innings pitched (P < .001), with significantly worse statistics for walks plus hits per inning pitched (P = .018).Conclusion:Professional baseball players who convert from position players to pitchers are injured at lower rates than control pitchers. Conversion pitchers have lower pitcher usage, which may contribute to their reduced injury rates.

Is Workload Associated with Internal Impingement in Professional Baseball Players? An Analysis of Days of Rest, Innings Pitched and Batters Faced (221)

Objectives:Determine if workload; as measured by number of days rest between outings, innings pitched, batters faced, and being a starting pitcher; associates with risk for internal impingement in professional baseball pitchers.Methods:All professional baseball pitchers who were diagnosed with internal impingement between 2011-2017 were identified using the major league baseball (MLB) Health and Injury Tracking System (HITS). A separate player usage dataset was used to determine workload. We then compared workload variables between pitcher-games 2, 6, 12, and >12 weeks prior to documented internal impingement and pitcher games from a control group who were never diagnosed with internal impingement. In a paired analysis, we compared the acute workload (2, 6, 12 weeks) prior to injury and the injured pitcher’s workload >12 weeks prior to injury.Results:There were 624 pitchers who suffered from internal impingement in professional baseball. Across all time points, players with more innings pitched per game, more batters faced per game, and fewer days rest in between games were associated with a subsequent internal impingement compared to controls. Pitchers who threw four or more innings per game had a 1.3-fold increase in percent of players with subsequent internal impingement compared to pitchers who threw only one inning per game. Significantly more starting pitchers were diagnosed with internal impingement over multiple time points compared to controls.Conclusions:Greater pitcher workload was associated with increased risk for internal impingement in professional baseball players. Throwing four or more innings per game increase a pitcher’s risk for internal impingement 1.3-fold compared to pitchers who threw one inning per game. Starting pitchers are more likely to sustain a LD/TM tear than control pitchers.

Update On Performance And Return To Sport After Biceps Tenodesis In Professional Baseball Players (226)

Objectives:Determine the return to sport (RTS) rate and performance upon RTS in professional baseball players who underwent biceps tenodesis.Methods:All professional baseball pitchers who underwent biceps tenodesis between 2014 and 2017 were included. Players with concomitant rotator cuff repair were excluded. Demographic and performance data (preoperative and postoperative) were recorded for each player. Performance metrics were then compared between the biceps tenodesis and matched control (no history of biceps tenodeses) groups.Results:14 players (average age 27±4 years; 12 pitchers, 2 position outfielders) were included. Most (79%) were open subpectoral tenodeses while one was an arthroscopic biceps transfer and one was arthroscopic suprapectoral. Fixation methods included cortical button (42%), interference screw (25%), suture anchor (25%) and drill holes (8%). Most players (79%) underwent concomitant procedures (43% underwent SLAP repair). Among the 14 players, 2 were unable to RTS, 5 RTS but to a lower level, and 7 RTS at the same or a higher level. Thus, overall, while 86% (12/14) were able to RTS, 50% (7/14) were able to return to the same or a better level and 50% were either unable to return or returned to a lower level. Among pitchers specifically, 100% (12/12) were able to return to play, but only 50% (6/12) were able to return to the same or a higher level. For those players who did return to play, it took 245±84 days, their performance was unchanged and did not differ from matched controls.Conclusions:While 86% of professional baseball players returned to sport following biceps tenodesis, only 50% returned at the same or higher level. No decline in performance was noted in players who successfully returned. Open subpectoral tenodesis is the most common tenodesis technique performed on professional baseball players.

Is Workload Associated with Ulnar Collateral Ligament Tears in Professional Baseball Players? An Analysis of Days of Rest, Innings Pitched and Batters Faced (126)

Objectives:To determine if workload; as measured by number of days rest between outings, innings pitched, batters faced, and being a starting pitcher; associates with risk for sustaining a subsequent UCL tear in professional baseball players.Methods:All professional baseball pitchers who sustained a UCL tear between 2011-2017 were identified using the major league baseball (MLB) Health and Injury Tracking System (HITS). A separate player usage was used to determine workload . We then compared these variables between player-games 2, 6, 12, and >12 weeks prior to a documented UCL tear and player games from a non-UCL tear control group. In a paired analysis, we compared the acute workload (2, 6, 12 weeks) prior to injury and the injured player’s workload >12 weeks prior to injury.Results:There were 2,204 elbow injuries within MLB, 369 of which were unique UCL tears in pitchers. In all time periods, player-games with more days rest, more innings pitched, and more batters faced associated with a subsequent UCL tear. Players who pitched 4 of more innings per outing had a 1.78-fold increase in percent of players with a subsequent UCL tear as compared to players with one inning pitched. Being a starting pitcher carried a relative risk of 1.51 (p<0.001) of subsequent UCL injury. In a paired analysis there were significantly more innings pitched and batters faced in the player-games 2 weeks prior to UCL injury than in the player-games >12 weeks prior to UCL injury (p=0.028 and p=0.017).Conclusions:Being a starting pitcher, pitching more innings per game, and facing more batters per game increased the risk of a UCL tear. An increase in workload in the 2 weeks prior to injury over that player’s baseline also significantly increased the risk for injury.

Ulnar collateral ligament reconstruction of the elbow at minimum 48-month mean follow-up demonstrates excellent clinical outcomes with low complication and revision rates: systematic review

ImportanceTears of the ulnar collateral ligament (UCL) of the elbow occur predominantly as an overuse injury, most commonly affecting throwing athletes, particularly baseball players. UCL reconstruction (UCLR) has been described as an effective treatment modality in the short term.ObjectiveThe purpose of this study was to systematically review the evidence in the literature to ascertain the clinical outcomes, complication and revision rates in baseball players following UCLR of the elbow at a minimum of 48 months of follow-up.Evidence reviewTwo independent reviewers performed a search of the literature based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the EMBASE, PubMed and Scopus databases. Clinical studies were included if they reported outcomes of baseball players at a minimum of 48 months following UCLR.FindingsOur review included 8 studies including 1104 baseball players (1105 elbows) at mean 69.9 months (48–205) following UCLR. The majority of baseball players were pitchers (92.3%), with a mean age of 22.2 years (13–42). At final follow-up, the overall return to play (RTP) was 95.3%%, with 85.3% returning at pre-injury level. In addition, the mean reported Conway-Jobe score was 86.8%, the revision rate was 6.0% with postoperative neuropathy reported in 2.4% of patients. A total of 479 (43.4%) were professional baseball players, with an overall RTP rate of 97.5% and 82.3% managing to RTP at their pre-injury level. The mean number of career years following UCLR was 4.7 years (0–22).Conclusion and relevanceUCLR provides excellent patient-reported and clinical outcomes to patients at medium-term follow-up with low complication and revision rates. In addition, high rates of RTP at pre-injury level and career longevity were reported by baseball players following UCLR.Level of evidenceLevel IV; Systematic Review

Professional Baseball Player Type and Geographic Region of Origin Impacts Shoulder External and Internal Rotation Strength.

BackgroundShoulder strength deficits are implicated in arm injuries and performance deficits in baseball players.PurposeTo characterize shoulder external (ER) and internal (IR) rotation strength in professional baseball players, and compare strength across player type (pitchers, position players) and geographic origin (North America, Latin America).Study DesignCross-sectional.MethodsMinor league professional baseball players from North America and Latin America (n=242; age=22.4±2.3 years; n=135 pitchers and n=107 position players; n=162 North American and n=80 Latin American players) volunteered at spring training. Bilateral shoulder IR and ER isometric strength was measured in sitting with the arm at the side using a handheld dynamometer stabilized on a wall via a specialized jig. Strength was normalized to body weight, and compared using t-tests between player type and geographic area of origin (p < 0.05).ResultsPosition players had greater strength in ER, IR and ER:IR (ER:0.7-2.7N/kg; IR:1.3-3.8N/kg; ER:IR ratio 0.36-1.22) compared to pitchers (ER:0.5-2.5N/kg; IR:0.6- 4.2N/kg; ER:IR ratio 0.44-1.16) on the throwing arm. North American pitchers had lower ER [MD= -0.4 (95%CI:-0.7,-0.2);p=0.002] and IR [MD= -0.2 (95%CI:-0.4,-0.1);p=0.006] than Latin American pitchers on the throwing arm. There were no differences between geographic groups for position players.Discussion/ConclusionsPlayer position and geographic origin influence shoulder rotational strength values in professional baseball players. Position players have 14 – 20% higher ER and IR isometric strength than pitchers. Moreover, Latin American pitchers exhibited 11.8% greater ER strength and 16.7% greater IR strength as compared to North American pitchers. Normative values can be used to determine player deficits, declines in performance, and targets for return to play after injury.Level of EvidenceLevel II

Rotational Shoulder Strength Profiles In North And Latin American Professional Baseball Pitchers And Position Players

Musculature of the shoulder acts to accelerate, decelerate and stabilize the arm during throwing. Shoulder rotational strength profiles can be leveraged to identify deficits that may explain a change in performance and injury risk. Previous studies of professional baseball players have not distinguished strength profiles across geographic areas of origin, and often only consider pitchers. PURPOSE: To characterize the effects of player position (Pitcher, Position Player) and geographic origin (North American, Latin American) on shoulder external (ER) and internal (IR) rotation strength in professional baseball players. METHODS: Minor league baseball players (N = 242, N = 135 Pitchers, N = 162 North American) participated. Each athlete completed two trials of maximal isometric ER and IR strength (arm at 0° abduction) using a handheld dynamometer. Strength data were normalized to bodyweight. RESULTS: Across both origins, position players were significantly stronger in ER (p < 0.001) and IR (p < 0.001) with higher ER:IR strength ratios (0.77 ± 0.17 vs. 0.73 ± 0.14, p < 0.043) compared to pitchers. Across all positions, Latin American athletes were significantly stronger in ER (mean difference (MD) = 0.3 N/kg, p < 0.001) and IR (MD = 0.2 N/kg, p < 0.001) compared to North American athletes. Specifically, Latin American pitchers were stronger in ER (MD = 0.4 N/kg, p = 0.002) and IR (MD = 0.2 N/kg, p = 0.006) compared to North American pitchers. No differences were found between position players of each region. North American pitchers were taller (189.3 cm ± 6.4 vs. 186.8 cm ± 5.6, p = 0.001) and heavier (94.6 kg ± 9.5 vs. 85.8 kg ± 13.4, p = 0.041) than Latin American pitchers. North American position players had similar heights but increased weight (89.1 kg ± 7.7 vs. 83.0 kg ± 11.5, p = 0.003) compared to Latin American position players. CONCLUSION: Player position and geographic origin are related to shoulder rotational strength values in professional baseball players. Latin American pitchers were stronger than North American pitchers when strength was normalized to bodyweight. These normative values can be used to determine player deficits, declines in performance, targets for return to play after injury, and advance strength and conditioning practices. Supported by a Major League Baseball research grant.

A Systematic Review of the Orthopaedic Literature on Truncal and Lower Extremity Injuries in Major League Baseball Players.

Background:Orthopaedic injuries in Major League Baseball (MLB) players can have a tremendous impact on player health, longevity, salaries, and time lost from play.Purpose:To summarize all data published between January 1980 and August 2019 on truncal and lower extremity orthopaedic injuries sustained by MLB players.Methods:A literature review of studies examining injuries in MLB was performed using the PubMed and Embase databases. Included studies focused on truncal and lower extremity injuries in professional baseball players. Studies pertaining to nonorthopaedic injuries, and case reports, were excluded.Results:A total of 41 articles met the inclusion criteria and were selected for the final analysis. Articles were divided based on anatomic region of injury: hip and pelvis (16%), thigh (15%), truncal (14%), knee (13%), and ankle (11%). Most studies (83.7%) were level 3 evidence. Most studies obtained data using publicly available internet resources (29.8%) compared with the MLB Health and Injury Tracking System (22.1%).Conclusion:This review provides physicians with a single source of the most current literature regarding truncal and lower extremity orthopaedic injuries in MLB players. Most research was published on hip and pelvic, truncal, and thigh injuries and consisted of level III evidence.

Epidemiology of Spine-Related Neurologic Injuries in Professional Baseball Players.

A retrospective case series study. To analyze the epidemiology of diagnoses of degenerative cervical and lumbar spinal conditions among Major League Baseball (MLB) and Minor League Baseball (MiLB) players. Repetitive high-energy forces in professional baseball players may predispose them to degenerative cervical and lumbar spinal conditions. There is a lack of data concerning the epidemiology of these injuries in professional baseball. Deidentified data on spine injuries were collected from all MLB and MiLB teams from 2011 to 2016 from the MLB-commissioned Health and Injury Tracking System database. Rates of diagnoses of common degenerative spinal conditions as well as their impact on days missed due to injury, necessitation of surgery, and player participation and career-ending status were assessed. Injury rates were reported as injuries per 1000 athlete-exposures in concordance with prior studies. Over 2011 to 2016, 4246 days of play were missed due to 172 spine-related injuries. 73.3% were related to the lumbar spine and 26.7% to the cervical spine. There were similar rates of surgery required for these injuries (18.3% of lumbar injuries vs. 13.0% of cervical injuries, P = 0.2164). Mean age of players with cervical injuries was higher compared with the lumbar group (27.5 vs. 25.4, P = 0.0119). Average number of days missed due to lumbar injuries was significantly higher than those due to cervical injuries (34.1 vs. 21.6 d, P = 0.0468). Spine injury rates for pitchers were significantly higher than those of other position players (0.086 per 1000 athlete-exposures vs. 0.037, P < 0.0001). Neurologic diagnoses relating to the cervical and lumbar spine lead to substantial disability among MLB and MiLB players as well as days missed from play. Pitchers have over double the rates of injury compared with other position players. Lumbar conditions were associated with significantly higher numbers of days missed from play.Level of Evidence: 4.

Lower Extremity Biomechanics Predicts Major League Baseball Player Performance.

Background:Although lower extremity biomechanics has been correlated with traditional metrics among baseball players, its association with advanced statistical metrics has not been evaluated.Purpose:To establish normative biomechanical parameters during the countermovement jump (CMJ) among Major League Baseball (MLB) players and evaluate the relationship between CMJ-developed algorithms and advanced statistical metrics.Study Design:Cohort study; Level of evidence, 3.Methods:MLB players in 2 professional organizations performed the CMJ at the beginning of each baseball season from 2013 to 2017. We collected ground-reaction force data including the eccentric rate of force development (“load”), concentric vertical force (“explode”), and concentric vertical impulse (“drive”) as well as the Sparta Score. The advanced statistical metrics from each baseball season (eg, fielding independent pitching [FIP], weighted stolen base runs [wSB], and weighted on-base average) were also gathered for the study participants. The minimal detectable change (MDC) was calculated for each CMJ variable to establish normative parameters. Pearson coefficient analysis and regression trees were used to evaluate associations between CMJ data and advanced statistical metrics for the players.Results:A total of 151 pitchers and 138 batters were included in the final analysis. The MDC for “load,” “explode,” “drive,” and the Sparta Score was 10.3, 8.1, 8.7, and 4.6, respectively, and all demonstrated good reliability (intraclass correlation coefficient > 0.75). There was a weak but statistically significant correlation between the Sparta Score and wSB (r = 0.23; P = .007); however, there were no significant correlations with any other advanced metrics. Regression trees demonstrated superior FIP with higher Sparta Scores in older pitchers compared with younger pitchers.Conclusion:There was a positive but weak correlation between the Sparta Score and base-stealing performance among professional baseball players. Additionally, older pitchers with a higher Sparta Score had statistically superior FIP compared with younger pitchers with a similar Sparta Score after adjusting for age.

Comparison of pain in the left and right shoulder joints, range of motion, and isokinetic strength in professional baseball players

Objective: This study investigated the pain of the shoulder joint in professional baseball players, the range of motion of the left and right inner and outer rotational rotations, the symmetry of the isokinetic muscle strength, and the correlation with pain. Method: In 30 professional baseball players, pain, left and right inner and outer rotational joint motion ranges, and isokinetic muscle strength were evaluated using the visual pain index for the shoulder joint. Independent t-test was performed to determine the difference between the permeable group and the non-permeable group, and Pearson correlation analysis was performed for the correlation with pain. Results: The correlation between pain and the symmetry of the range of motion of the left and right shoulder joints showed significant correlations for the inner and outer rotations, r=.725 and r=.746, respectively. The correlation between pain and the 120° isokinetic muscle strength symmetry was statistically significant, with r=.635 r=.698, respectively, in the inner and outer rotations, respectively. Conclusion: The symmetric ratios of the inner and outer rotational motion ranges of the left and right shoulder joints and the isokinetic muscle strength were not statistically significant in the two groups. The asymmetry of the permeable group was greater than that of the non-permeable group, and pain was correlated with the range of motion of the joint and the isokinetic muscle strength.

Stress-Distribution Pattern Across the Glenohumeral Joint in Collegiate and Professional Baseball Players: A Computed Tomography Osteoabsorptiometry Study.

Background:The influence of long-term loading conditions on the articular surfaces of the glenohumeral joint can be determined by measuring stress-distribution patterns. Long-term pitching activity changes the stress distribution across the glenohumeral joint surface; however, the influence of competitive level on stress-distribution patterns remains unclear.Purpose:To use computed tomography (CT) osteoabsorptiometry (CTOAM) to evaluate the distribution of subchondral bone density across the glenohumeral joint in collegiate and professional baseball players as well as to determine the effects of pitching activity on the articular surfaces.Study Design:Descriptive laboratory study.Methods:We evaluated 73 shoulders in 50 baseball players. CT imaging data were obtained from the dominant-side shoulder of 12 professional pitchers (PP group) and 15 professional fielders (PF group). CT imaging data were also obtained from both shoulders of 12 asymptomatic collegiate pitchers (CP group) and 11 collegiate fielders (CF group). The pattern of distribution of subchondral bone density across the articular surfaces of each glenohumeral joint was assessed by CTOAM. As a measure of bone density, the mean Hounsfield units (HU) were obtained for each joint surface, and the absolute values of the dominant shoulder were compared for each group.Results:Stress-distribution patterns over the articular surfaces differed between the dominant and nondominant sides in the CP group as well as between both collegiate groups versus the PP group. In the CP group, the mean HU of the humeral head surface were greater on the nondominant versus dominant side (P = .035). On the dominant side, the mean HU of the humeral head surface and glenoid were greater in the CP versus the PP group (P = .001 and .027, respectively).Conclusion:Stress distribution on the articular surface of the glenohumeral joint was affected by pitching ability and competitive level. Our analysis indicates that the traction force on the glenohumeral joint surface might be greater than compression force during pitching.Clinical Relevance:The present findings suggest that pitching activity results in low stress to the articular surfaces of the glenohumeral joint. This supports the notion that mechanical conditions play a crucial role in the etiology of disorders specific to pitching activity.

Structural Relationship between Physical Self-Concept, Occupational Instability, and Retirement Intention among South Korean Minor League Baseball Players

This study aimed to verify the structural relationship between physical self-concept, occupational instability, and retirement intention among South Korean minor league baseball players. Snowball sampling was used to recruit 180 minor league players who belonged to the South Korean professional baseball team and were active as of December 2020; data were collected through an online survey. Frequency analysis, psychometric validation, descriptive statistical analysis, and path analysis were performed. The results revealed that for these participants, (1) physical self-concept had a significant negative effect on their occupational instability; (2) physical self-concept did not directly affect their retirement intention; and (3) occupational instability had a significant positive effect on their retirement intentions. These results suggest the need to devise a plan addressing the practical difficulties experienced by professional minor league baseball players and improve the physical self-concept of these players to adapt to involuntary retirement. Additionally, a supportive environment should be created to reduce mental health risks.

Hook of Hamate Fractures in Major and Minor League Baseball Players

The purpose of this study was to describe an approach to surgical management of the hook of hamate fractures in professional baseball players. A retrospective chart review was performed on Major and Minor League Baseball players who underwent surgical excision for the hook of hamate fracture between the years 2003 and 2019 by a single surgeon. Patient demographics, the mechanism and timing of the injury, diagnostic and operative details, postoperative complications, and timeline to return to baseball activities were recorded. A total of 145 professional baseball players affiliated with 17 Major League Baseball organizations were studied, with the majority of athletes playing at the Minor League Baseball level (91.7%). Subacute or chronic patterns of injury (81.7%) were found to be more common than acute patterns based on radiographic and intraoperative findings. Two patients reported transient numbness in the fourth and fifth digits after surgery, 6 patients reported pisotriquetral pain when returning to a hitting program, and 1 patient developed heterotopic ossification after surgery. All complications resolved during a strength and conditioning program. On average, players in our cohort began a hitting program at 4.6 weeks after surgery and were released into full baseball activities at 7.1 weeks after surgery. Surgical excision remains an effective method of management, with a low risk of minor complications for both acute and chronic hook of hamate fractures in professional baseball players. Therapeutic Level IV.