Impact of Climate on Stress Ultrasound Findings of the Elbow Ulnar Collateral Ligament in Professional Baseball Pitchers: An 18-Year Study.

Background: The ulnar collateral ligament (UCL) is the primary soft tissue stabilizer to valgus stress in the elbow and is placed under this valgus stress during the throwing motion. Although there are known risk factors for UCL injury, it is unknown whether the UCL undergoes adaptive changes in athletes from different climates. Purpose: To compare elbow stress ultrasound (SUS) findings between professional baseball pitchers from warm climates versus cold climates and assess significant differences in adaptive and morphologic changes in the UCL. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Dynamic SUS evaluations were performed over 18 years on the dominant and nondominant arms of 643 professional pitchers from warm and cold climates as determined by the player's country/state of origin. Studies were compared with respect to relative UCL thickness (dominant arm vs nondominant arm), relative glenohumeral joint laxity (joint space distance under stress vs joint space distance at rest), and the presence of morphologic changes such as tears or calcifications. In addition, a subgroup analysis was performed to compare the progression of SUS findings over 3 years in players with sequential yearly data. Results: Players from warmer climates had significantly greater relative UCL thicknesses than players from colder climates (1.75 vs 1.50 mm, respectively; P = .047). There were no differences between these 2 groups in terms of relative ulnohumeral joint laxity (P = .201), presence of morphologic changes (P = .433), 3-year progression of relative UCL thickness (P = .748), or relative joint laxity (P = .904). Conclusion: Professional pitchers from warm climates had a greater side-to-side difference in UCL thickness between the dominant and nondominant arms. This may be due to the potential for year-round throwing among baseball players from warm climates. There was no difference in laxity, thickness progression, laxity progression, or the presence of additional morphologic changes.

Shoulder and elbow symptoms in talented Dutch baseball pitchers: results of a two-season prospective study.

CONTEXT: Baseball pitching requires fast and coordinated motions of the whole body to reach high ball speeds, putting considerable strain on the musculoskeletal system, particularly the shoulder and elbow. DESIGN: Descriptive epidemiology study. OBJECTIVE: To describe musculoskeletal symptoms and the functional status of the shoulder and elbow in male high school baseball pitchers. SETTING: Dutch baseball talent academies. PATIENTS OR OTHER PARTICIPANTS: 125 male high school baseball pitchers aged 12 to 18 years, who participated in one of the six Dutch baseball talent academies and the Dutch National U-18 team were recruited and enrolled. MAIN OUTCOME MEASURE(S): Musculoskeletal symptoms, functional status of the shoulder and elbow were registered for each player every six months over two consecutive baseball seasons through self-assessment questionnaires, including the Kerlan-Jobe Orthopaedic Clinic (KJOC) and the Western Ontario Shoulder Instability Index (WOSI) questionnaires. RESULTS: 570 musculoskeletal (MSS) symptoms in 93 of the 125 players were reported. The average six-month prevalence for symptoms of the throwing shoulder was 37% (95% CI: 33% - 41%), and for the elbow 37% (95% CI: 31% - 42%), followed by the lower back with 36% (95% CI: 26% - 45%). The baseball pitchers who experienced only shoulder symptoms had an average KJOC score of 80.0 (95% CI: 75.3-84.7) points, while those with only elbow symptoms reported a score of 90.2 (95% CI: 89.2-95.3). On the WOSI questionnaire, baseball pitchers scored an average of 421.2 (95% CI: 200.1 - 642.4) points. CONCLUSION: In a cohort of Dutch high school baseball pitchers, one-third reported shoulder and elbow symptoms on the throwing side, with reduced functional status and lower back symptoms. Future efforts should focus on developing preventive strategies through early symptom detection, aiming to prevent symptom progression and, ultimately, the development of severe injuries.

Characteristics of Lumbar Spondylolysis in Adolescent Baseball Players: Relationship between the Laterality of Lumbar Spondylolysis and the Throwing or Batting Side.

Study Design: A retrospective, cross-sectional study was conducted to analyze the implications of asymmetric baseball movements on the incidence of spondylolysis. Purpose: This study aimed to evaluate the relationship between asymmetric movements and the laterality of spondylolysis. Overview of Literature: Baseball, characterized by its asymmetric throwing and batting, may disproportionately stress one side. Lumbar spondylolysis is a frequent cause of lower back pain in young athletes, particularly those involved in activities with consistent unilateral rotations such as baseball. However, whether a link exists between the laterality in spondylolysis and the dominant throwing/ batting side or whether disparities exist between pitchers and fielders remains unclear. Methods: The study included 85 players. Participants were divided into two groups: pitchers and fielders. The association between the laterality of spondylolysis and the throwing/batting side in the overall cohort and between the two groups was evaluated. Results: Among pitchers, 16 lesions appeared on the throwing side and 32 on the nonthrowing side (p =0.029). For fielders, no notable difference was observed between the two sides (p =0.363). Furthermore, batting preference did not influence the laterality of spondylolysis in either group. Conclusions: Adolescent baseball players, particularly pitchers, exhibited a higher incidence of lumbar spondylolysis on the side opposite their throwing arm. The findings of this study highlight the significant effect of asymmetrical sporting activities on the development of spondylolysis, to which pitchers are particularly susceptible.

Epidemiology of Knee Injuries in Baseball Players from the State of São Paulo.

Objective This study aimed to identify the main knee complaints and injuries associated with baseball and their prevalence in the state of São Paulo, Brazil. Methods This epidemiological study analyzed data from an online questionnaire sent to baseball athletes from the state of São Paulo, Brazil, from 2019 to 2022. Results Ninety-eight athletes participated in the study. Their average age was 24.3 years, and 85.72% of the subjects were men. The most prevalent ethnicities were yellow (50%) and white (42.86%). Most athletes had incomplete or complete higher education (75.5%). Most (88.77%) have been training for over 1 year, and 40.82% played in more than 1 position. More than half also practiced another sport. Most (66.32%) athletes present knee complaints or symptoms, and 37.75% had suffered a knee injury playing baseball, with several mechanisms (contact with the ground, contact with another player, or no contact). More than half (59.45%) of the athletes required time away from baseball due to complaints, symptoms, or injuries. Conclusion Among the athletes interviewed, 66.32% had a knee complaint, and 37.75% had already had a knee injury, especially meniscal and ligament injuries. The injury rate was highest in the first year of practice.

Arthroscopic Shoulder Stabilization in High School Football Players.

Background: Destabilizing shoulder injuries are common in high school American football players; however, the rate of recurrent glenohumeral instability and return to play after arthroscopic labral stabilization surgery remains unknown. Purpose/Hypothesis: The purpose of this study was to determine the rate of recurrent instability on return to competitive high school football after arthroscopic shoulder labral stabilization and capsulorrhaphy procedures. It was hypothesized that the instability rate would be greater in players with more years of eligibility remaining (YER) to play at the high school level. Study Design: Case series; Level of evidence, 4. Methods: Consecutive male high school football players with at least 1 YER who sustained at least 1 anterior traumatic inseason shoulder instability episode and underwent arthroscopic stabilization between 2012 and 2017 were identified. Patients and/or families were contacted by phone to discuss (1) recurrent instability episodes and (2) return to competitive sport and/or recreational athletic activity. Statistical analysis was conducted using chi-square tests to compare recurrent shoulder instability with return to play and YER. Results: A total of 45 football players aged 14 to 17 years were included, with a mean follow-up of 4.1 years. Most patients (60%) chose not to return to competitive football, due mainly to fear of recurrent injury. Overall, the recurrent instability rate was 15.6% (7/45). The instability rate in players who returned to football was 16.7%, with 66.7% requiring revision surgery. The instability rate in patients who did not return to football was 14.8%, with no revision procedures required. In players who returned to football, the instability rate in YER group 4 was significantly higher than that in YER groups 1 to 3 (42% vs 10.5%, respectively, P = .03), with each year of play conferring an additional 10% risk of reinjury. There was a significant difference in the type of recurrent instability in players who returned to any sport versus those who did not (P = .029). Conclusion: High school football players who returned to competitive play after arthroscopic shoulder stabilization surgery experienced a higher rate of recurrent instability that was dependent on their YER. Over half of the players chose not to return to football, with fear of reinjury being the most common reason.

Limited total arc range of motion increases sheer stress in the shoulder while pitching in collegiate baseball pitchers.

CONTEXT: Upper extremity injuries in baseball pitchers cause significant time-loss from competing and decreased quality of life. Although shoulder range of motion (ROM) is reported as a key factor to prevent potential injury, it remains unclear how limited glenohumeral ROM affects pitching biomechanics which may contribute to upper extremity injuries. OBJECTIVE: To investigate how pitchers with decreased total arc glenohumeral ROM of the throwing arm differed in upper extremity pitching kinematics and kinetics as well as ball velocity compared to pitchers with greater levels of glenohumeral ROM. DESIGN: Cross-sectional Study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifty-seven baseball pitchers (ages 18-24) were divided into either control (≧160° total arc) or lower ROM (<160° total arc) groups. MAIN OUTCOME MEASURE(S): The mean glenohumeral ROM deficits, pitching kinematic and kinetic outcomes, and ball velocity were compared between groups. RESULTS: The control group demonstrated significantly less deficit in total arc ROM between arms than the lower ROM (Control: -1.5±10.0°, Lower ROM: -12.4±13.9°, p<.001). While, the lower ROM group displayed less maximal shoulder external rotation (ER) while pitching, the control group had significantly less difference in ROM between maximal shoulder ER while pitching and clinically-measured ER (Lower ROM: 64.4±12.1°, Control: 55.8±16.6°, p=.025). The control group had significantly faster ball velocity compared to the lower ROM group (Control: 85.0 ± 4.3mph, Lower ROM: 82.4 ± 4.8mph, p=.024). CONCLUSION: Pitchers with decreased total arc glenohumeral ROM (<160° total arc) may undergo over-stretching toward ER in the shoulder during the late cocking phase. Pitchers with higher total arc ROM can pitch the same or faster ball without increasing loading in the upper extremity. Total arc glenohumeral ROM measurement can be a clinical screening tool to monitor shoulder condition over the time, and pitchers with limited total arc ROM might be at higher risk of shoulder injury.

UCL Throwing Injuries in Nonprofessional Baseball Players: A 14-Year Retrospective Study.

BACKGROUND: This study evaluated treatment modality (surgical vs nonoperative) of medial ulnar collateral ligament (UCL) injuries in nonprofessional throwing baseball athletes by comparing type, severity, and location of UCL injury. HYPOTHESIS: Baseball players with closed medial epicondyle physes and concomitant throwing-related UCL injury will be more likely to undergo surgical intervention than players with open medial epicondyle physes. STUDY DESIGN: Retrospective. LEVEL OF EVIDENCE: Level 5. METHODS: A total of 119 baseball players with a mean age of 16.9 ± 2.5 years (range, 11-25 years) were included in the study. Datapoints included sex, age at time of injury, severity, and location of UCL injury, growth plate status, operative versus conservative management, and concomitant flexor forearm injury. RESULTS: A total of 75 players were treated conservatively; 43 underwent UCL reconstruction (UCL-R), and 1 had an unknown treatment outcome. No significant difference was found for age related to treatment type, UCL-R (17.2 ± 2.2) versus conservative treatment (16.8 ± 2.6). Athletes with closed medial epicondylar growth plates were more likely to undergo UCL-R than athletes with open medial epicondylar growth plates (P = 0.02). There were no significant differences between UCL injury location (42 distal, 37 proximal, 18 combined tear locations, 11 complete tears, and 11 intact UCLs with inflammation) by treatment type (P = 0.09). There was a significant difference for UCL severity (11 complete tears, 96 partial tears) by treatment type (P = 0.03). CONCLUSION: Nonprofessional athletes with closed medial epicondylar growth plates and throwing-related UCL injuries were more likely to be treated surgically. Baseball athletes with partial tears, if skeletally immature, require further long-term evaluation. CLINICAL RELEVANCE: Continued knowledge gains in this area of throwing medicine will further improve our treatment algorithms in nonprofessional baseball players.

Interval Throwing Programs for Baseball Players: Methodological Assessment of the Quality and Construct of Publicly Available Programs.

CONTEXT: The quality and interprogram variability of publicly available throwing programs have not been assessed. OBJECTIVE: To (1) identify publicly available interval throwing programs, (2) describe their components and structure, and (3) evaluate their quality, variability, and completeness. DATA SOURCES: Google, Bing, Yahoo; keyword: "interval throwing program." STUDY SELECTION: Baseball-specific publicly available programs. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Independent evaluation by 2 authors using a novel 21-item Quality Assessment Rubric (QAR). RESULTS: Of the 99 included programs, 54% were designed for return from injury/surgery; 42% explicitly stated no expected timeline for completion, and approximately 40% did not provide criteria to initiate the program. Program construction was highly variable. There were broad-ranging shortest (mean: 40±8 ft, range: 20-45 ft) and longest (mean: 150±33 ft, range: 90-250 ft) long toss distances, and variable maximum numbers of mound pitches thrown before returning to game play (range: 40-120, mean: 85). Only 63% of programs provided guidelines for handling setbacks, and standardized warm-ups, arm care, and concomitant training were absent in 32%, 63%, and 47% of programs, respectively. Mean QAR completion rate and QAR item response rate were low (62 ± 4% [range, 24-91%], 62 ± 24% [range, 7-99%], respectively). Finally, only 20 (20%) programs provided at least 1 peer-reviewed reference, most of which were published >10 years ago. CONCLUSION: Publicly available interval throwing programs are readily available but demonstrate significant interprogram heterogeneity across multiple areas including target audience, program construction, progression, and execution. The quality and consistency of publicly available interval throwing programs is poor at this time, which may limit their utility and effectiveness for baseball players attempting to return to competition. This work identifies a multitude of deficiencies in currently available throwing programs that should be targets of future improvement efforts.

An Interval Throwing Program for Baseball Pitchers Based upon Workload Data.

Background: Interval throwing programs (ITP) have been used for decades to enable baseball pitchers to return to competition after injury or surgery by gradually applying load to the throwing arm. Past programs have been based on personal experience; however, advances in our understanding of the biomechanics and workloads of throwing allow for a more modern data-based program to be developed. Hypothesis/Purpose: To 1) develop a updated ITP for rehabilitation of modern baseball pitchers based upon biomechanical and throwing workload data, and 2) compare the updated program with a past program to determine differences in chronic workload and acute:chronic workload ratios (ACWR). Study Design: Cross-sectional study. Methods: Workloads (i.e. daily, acute, chronic, and ACWR) for the original ITP were built from the prescribed throwing schedule. Elbow varus torque per throw was calculated based upon a relationship between elbow varus torque and throwing distance. Throw counts, daily/chronic/acute workloads, and ACWR were calculated and plotted over time. A new ITP was built to model current pitcher's throwing schedules and gradually increased ACWR over time. Results: The original ITP had a throwing schedule of 136 days, final chronic workload 15.0, and the ACWR above or below the "safe" range (i.e. 0.7 - 1.3) for 18% of the program with a peak of 1.61. The updated ITP was built to consist of a 217-day schedule, final chronic workload of 10.8, and deviated from the safe range for 9% of the program, with a peak of 1.33. Conclusion: The newly created ITP is more familiar to modern baseball pitchers while exhibiting a more gradual buildup of chronic workload than traditional ITP programs. This ITP may be used to return baseball pitchers back to competition as safely and efficiently as possible, and potentially with less risk of setbacks or reinjury. The ITP may be used following common injuries or surgeries to the throwing shoulder and elbow, such as Tommy John surgery, while also serving as a basis for future development of shorter duration ITPs. Level of Evidence: 2c.

Temperamental and Neuropsychological Predictors for Major League Pro-Baseball Success.

BACKGROUND: Securing a professional baseball career is a formidable task, and only a unique few can overcome the obstacles necessary to become a Major League player in the Korea Baseball Organization (KBO). When achieving a spot in a KBO Major League team, a player's technical aspect may be influenced by their initial neuropsychological status. HYPOTHESIS: Personality and neurocognitive functions influence long-term pro-baseball league success. STUDY DESIGN: Cohort observational study. LEVEL OF EVIDENCE: Level 3. METHODS: From the start of each player's career, we monitored the status and course of 153 baseball players in the KBO from 2009 to 2019 who agreed to participate in this study. The Korean versions of the Temperament and Character Inventory (TCI) and the State-Trait Anxiety Inventory-Y (STAI-KY) analyzed traits and estimated state and trait anxiety levels, respectively. The Trail Making Test (TMT) (parts A and B) assessed attention shifting, and, in the Wisconsin Card Sorting Test (WCST), perseverative errors determined cognitive flexibility. Hierarchical logistic regression models were used to predict player status variables, with TCI and neurocognitive function variables as covariates. RESULTS: High novelty-seeking scores, low state anxiety, and short TMT A results reliably predict KBO Major League participation in a player's third year. Similarly, low state anxiety scores and high harm avoidance, reward dependence, and self-transcendence scores accurately predict KBO Major League participation in a player's fifth year. Lastly, short TMT A results, low perseverative error scores, and high novelty-seeking, harm avoidance, reward dependence, and self-transcendence efficiently predict KBO Major League participation in a player's seventh year. CONCLUSION: Draft ranking, personality, and neurocognitive function are associated with pro-baseball league achievement. In particular, personality and neuropsychological functions are associated with long-term success. CLINICAL RELEVANCE: Clinically, sound personality and neuropsychological functions determine KBO Major League success.

Dynamic Stress Ultrasound Assessment of Professional Baseball Players' Elbows After Ulnar Collateral Ligament Reconstruction.

BACKGROUND: There is a paucity of data analyzing dynamic stress ultrasound (SUS) findings in elite pitchers who have undergone ulnar collateral ligament (UCL) reconstruction (UCLR) and returned to sport. PURPOSE: To identify longitudinal, perioperative changes in the elbows of professional baseball pitchers who have undergone UCLR and to compare these findings with a matched cohort of healthy pitchers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This study used prospectively collected data from dynamic elbow SUS analyses of professional baseball pitchers within a single Major League Baseball organization. Pitchers were divided into 2 cohorts: a UCLR cohort and healthy cohort. The UCLR cohort eligibility included availability of (1) SUS from preseason of injury/UCLR and (2) SUS from ≥2 years after surgery. These players were 1:1 matched to players with no history of upper extremity injury to form the healthy cohort. Ligament thickness and ulnohumeral joint space at rest and under stress were directly measured. Joint laxity was calculated by subtracting joint space at rest from joint space under stress. The term "relative" was used to describe calculated differences where nondominant measurements were subtracted from dominant-side measurements. RESULTS: Eight pitchers were included in the UCLR group and matched to 8 healthy pitchers (mean age at initial SUS examination, 19.6 years). At a minimum follow-up of 2 years, there were no significant differences between groups in terms of relative or dominant arm rest space, stress space, or laxity. Longitudinally (final measurements - baseline measurements), the mean relative ulnohumeral rest space decreased in the UCLR group and increased in the healthy group (-0.36 mm vs +0.50 mm; P = .032). The finding of increased UCL thickness in the UCLR group was expected, as UCL grafts are typically thicker than native ligaments. CONCLUSION: Ulnhohumeral joint stability was achieved after UCLR as indicated by similar rest space, stress space, and joint laxity in dominant arms compared with a matched healthy cohort. A significant decrease in relative rest space after UCLR may represent the achievement of stability in surgery patients. Alternatively, the increase in ulnohumeral rest space seen in the healthy cohort may represent adaptive changes from pitching at a professional level.

The Utility of Stress Ultrasound in Identifying Risk Factors for Elbow Ulnar Collateral Ligament Tear: A Longitudinal Study of 203 Professional Baseball Players.

BACKGROUND: Injuries to the medial ulnar collateral ligament (UCL) are common among baseball pitchers due to repetitive stress on the soft tissue stabilizers of the elbow during pitching. Dynamic stress ultrasound (SUS) can be used to evaluate the UCL and ulnohumeral joint to identify anatomic risk factors of those who will require UCL reconstruction (UCLR). PURPOSE: To determine whether any adaptive or morphological changes detectable on SUS can predict injury to the UCL in professional baseball pitchers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 203 professional baseball pitchers who underwent SUS at preseason training sessions over the course of 18 years were categorized into 1 of 2 groups: those without a history of shoulder, arm, elbow, or forearm surgery or injuries (healthy cohort; n = 184) and those who underwent UCLR the same season as SUS (UCLR cohort; n = 19). Ligament thickness, joint spacing, and laxity were compared. An additional matched cohort analysis was conducted using 10 players from each group to detect differences in the progression of UCL and ulnohumeral joint measures in the year before injury. RESULTS: The UCLR cohort, when compared with the healthy cohort, had higher relative (ie, nondominant-side measurements subtracted from dominant-side measurements) resting ulnohumeral joint space (median, 0.50 vs 0.20 mm, respectively; P = .006) and higher rates of hypoechoic foci (57.9% vs 30.4%, respectively; P = .030). Players of both groups had similar dominant UCL thickness (P = .161), ulnohumeral joint space at rest (P = .321), space under stress (P = .498), and laxity (P = .796). Groups did not differ in terms of relative UCL thickness, ulnohumeral joint space under stress, or relative laxity. In the year before UCL injury, the UCLR cohort, compared with the matched healthy cohort, had a greater increase in mean dominant UCL thickness (0.94 vs -0.60 mm, respectively; P = .038) and a greater increase in relative median UCL thickness (1.35 vs -0.35 mm, respectively; P = .045). Players in the healthy cohort were statistically older than those in the UCLR cohort (23 vs 22 years, respectively; P = .004). No differences in ulnohumeral stress spacing or laxity were detected. CONCLUSION: SUS of players who underwent UCLR demonstrated a progressive increase in UCL thickness over 1 year, higher rates of hypoechoic foci, and increased ulnohumeral rest space compared with SUS of uninjured players.

Development of the NOCSAE Standard to Reduce the Risk of Commotio Cordis.

BACKGROUND: Commotio cordis, sudden cardiac death (SCD) caused by relatively innocent impact to the chest, is one of the leading causes of SCD in sports. Commercial chest protectors have not been demonstrated to mitigate the risk of these SCDs. METHODS: To develop a standard to assess chest protectors, 4 phases occurred. A physiological commotio cordis model was utilized to assess variables that predicted for SCD. Next, a surrogate model was developed based on data from the physiological model, and the attenuation in risk was assessed. In the third phase, this model was calibrated and validated. Finally, National Operating Committee on Standards for Athletic Equipment adopted the standard and had an open review process with revision of the standard over 3 years. RESULTS: Of all variables, impact force was the most robust at predicting SCD. Chest wall protectors which could reduce the force of impact to under thresholds were predicted to reduce the risk of SCD. The correlation between the experimental model and the mechanical surrogate ranged from 0.783 with a lacrosse ball at 30 mph to 0.898 with a baseball at 50 mph. The standard was licensed to National Operating Committee on Standards for Athletic Equipment which initially adopted the standard in January 2018, and finalized in July 2021. CONCLUSIONS: An effective mechanical surrogate based on physiological data from a well-established model of commotio cordis predicts the reduction in SCD with chest protectors. A greater reduction in force provides a great degree of protection from commotio cordis. This new National Operating Committee on Standards for Athletic Equipment standard for chest protectors should result in a significant reduction in the risk of commotio cordis on the playing field.

Preventive interventions for throwing injuries in baseball players: A scoping review.

BACKGROUND: Shoulder and elbow pain are the common complaints associated with throwing injuries in baseball players. Prospective studies evaluating the effectiveness of stretching in increasing posterior shoulder flexibility or strengthening the external rotator muscles as preventive strategies for throwing injuries in baseball players have been published. However, there are limited reviews highlighting the role of preventive interventions for throwing injuries in baseball players. Therefore, this scoping review aimed to summarize the existing literature on preventive interventions for throwing injuries in baseball players. METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Scopus databases on 3 March 2023. Two independent reviewers screened the studies based on the eligibility criteria. We extracted existing literature on preventive interventions and effectiveness for throwing injuries in baseball players, and participants' characteristics and results were extracted from the studies. This scoping review was performed in accordance with the Extended Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement for Scoping Reviews. RESULTS: The initial database search yielded 1170 articles, four of which met the eligibility criteria. Of the included studies, two were randomized controlled trials, and the remaining two were prospective cohort studies. Eligible studies targeted youth- to high school-level players and focused on preventive programs for throwing injuries that manifest in the upper extremities of baseball players. The outcome measure most commonly used to quantify the effectiveness of prevention programs was the incidence of shoulder and elbow injuries, although the definitions vary among studies. The prevention program included sleeper stretching, shoulder external rotation strengthening exercises, and comprehensive prevention programs (focusing on improving the elbow, shoulder, and hip range of motion; rotator cuff and periscapular muscle strength; posture; and lower extremity balance). Each prevention program was reported to have the potential to reduce the incidence of throwing injuries in baseball players, and two studies suggested that high compliance with the program led to a lower injury risk. CONCLUSION: This scoping review confirmed the presence of studies that examined preventive interventions for throwing injuries in baseball players. Preventive interventions that may reduce throwing injuries in baseball players include sleeper stretching, shoulder external rotation strengthening exercises, and comprehensive prevention programs. However, the characteristics of participants (e.g., age, sports level, and position) and the definition of injury varied among previous studies. Injury profiles and prevention strategies may differ according to age, sport level, and position of players, and more studies are needed to prove this issue.

Relationship between shoulder and elbow range of motion and ultrasonographic structural abnormalities in the elbow of Taiwanese high school baseball players.

BACKGROUND: Ultrasonographic structural abnormalities are regarded as one of the risk factors of elbow injuries. Elbow injuries are commonly associated with decreased shoulder/elbow range of motion (ROM). The purpose of this study is to determine the relationship between shoulder/elbow ROM and elbow ultrasonographic structural abnormalities in Taiwan high school baseball players. METHODS: A total of 533 Taiwan high school baseball players were enrolled. Physical examinations including measurements on shoulder/elbow ROM and elbow sonographic examinations were performed and recorded by professional physicians. The analyses were conducted in three subgroups according to their defensive position because the training programs were different. All players pooled, pitchers-only, and fielders-only, due to several demographic differences among these subgroups. In all the subgroups, univariate analyses were conducted separately for participants with and those without elbow ultrasonographic structural abnormalities, and then multivariate analyses were conducted to identify factors significantly related. The odds ratios (ORs) were used to estimate the risk of elbow ultrasonographic structural abnormalities. RESULTS: Demographic data showed that pitchers had taller body height (P < 0.001) and greater elbow flexion/extension ROM (P < 0.001). When all players were pooled, significant risk factors included started playing baseball at an younger age (OR = 1.202; 95% CI = 1.064-1.357; P = 0.003), longer experience of official baseball (OR = 1.154; 95% CI = 1.038-1.283; P = 0.008), lower total shoulder rotation angle (OR = 1.007; 95% CI = 1.000-1.014; P = 0.050), and less total elbow arm angle (OR = 1.052; 95% CI = 1.017-1.088; P = 0.003) For pitchers, significant risk factors included longer experience of official baseball (OR = 1.342; 95% CI = 1.098-1.640; P = 0.004), lower total shoulder rotation angle (OR = 1.016; 95% CI = 1.004-1.027; P = 0.006), and lower total elbow arm angle (OR = 1.075; 95% CI = 1.024-1.129; P = 0.004) (Table 5). There were no significant risk factors for elbow structural abnormalities in fielders. CONCLUSION: For Taiwan high school pitchers, longer official baseball experience, decreased shoulder total rotational angle, and decreased elbow total flexion/extension angle, were related to ultrasonographic structural abnormalities in elbows.

Predicting elbow load based on individual pelvis and trunk (inter)segmental rotations in fastball pitching.

The baseball pitch is a repetitive, full-body throwing motion that exposes the elbow to significant loads, leading to a high incidence of elbow injuries. Elbow injuries in pitching are often attributed to high external valgus torques as these are generally considered to be a good proxy for the load on the Ulnar Collateral Ligament. The aim of the study is to contribute to elbow load monitoring by developing a prediction model based on the pelvis and trunk peak angular velocities and their separation time. Eleven male youth elite baseball pitchers (age 17 ± 2.2 years) threw 25 fastballs at full effort off a mound. Two-level varying-intercept, varying-slope Bayesian models were used to predict external valgus torque based on (inter)segmental rotation in fastball pitching with pitcher's weight and height added to strengthen the individualisation of the prediction. The results revealed the high predictive performance of the models including a set of kinematic parameters trunk peak angular velocity and the separation time between the pelvis and trunk peak angular velocities. Such an approach allows individualised prediction of the external valgus torque for each pitcher, which has a great practical advantage compared to group-based predictions in terms of injury assessment and injury prevention.

Return-to-play outcomes after full-endoscopic spine surgery under local anesthesia in professional baseball players: Comparison by timing of surgery.

BACKGROUND: Full-endoscopic spine surgery via a transforaminal approach (TF-FESS) is minimally invasive and could help athletes quickly return to play. When treating professional athletes, we have to consider their season schedule. In this study, we investigated the characteristics of Japanese professional baseball players who underwent TF-FESS and examine how the timing of surgery influenced their postoperative course. METHODS: Ten players who underwent TF-FESS (discectomy, foraminoplasty, or thermal annuloplasty according to their diagnosis) under local anesthesia were analyzed. Multilevel surgeries were performed at the same time in patients with lesions at multiple levels. The patients were divided into three groups according to timing of surgery (pre/during/post-season). Time to complete return to play and duration of official game loss were compared between the three groups. RESULTS: All players (100 %) could return to their original level of professional play after FESS surgery. Seven of the 10 patients underwent two-level surgery. The mean time until complete return to play was 4.6 months (range, 2-8 months) and the mean duration of game loss was 1.5 months (range, 0-4 months). The mean duration of game loss was shorter in the post-season group than in the other groups (0.9 vs 2,4 months), and 4 of 6 patients in the post-season group did not miss any games. CONCLUSIONS: TF-FESS is a good technique for achieving a quick return to play in professional baseball players. In particular, surgery performed during the post-season could allow players to return to play after adequate rehabilitation with no game loss.

Biomechanical Characteristics of Ulnar Collateral Ligament Injuries Treated With and Without Augmentation: A Network Meta-analysis of Controlled Laboratory Studies.

BACKGROUND: Treatment of ulnar collateral ligament (UCL) tears with suture tape augmentation has gained interest given preliminary reports of favorable biomechanical characteristics. No study to date has quantitatively assessed the biomechanical effects of multiple augmentation techniques relative to the native UCL. PURPOSE: To perform a systematic review and meta-analysis of controlled laboratory studies to assess and comparatively rank biomechanical effects of UCL repair or reconstruction with or without augmentation. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: PubMed, OVID/Medline, and Cochrane databases were queried in January 2023. A frequentist network meta-analytic approach was used to perform mixed-treatment comparisons of UCL repair and reconstruction techniques with and without augmentation, with the native UCL as the reference condition. Pooled treatment estimates were quantified under the random-effects assumption. Competing treatments were ranked in the network meta-analysis by using point estimates and standard errors to calculate P scores (greater P score indicates superiority of treatment for given outcome). RESULTS: Ten studies involving 206 elbow specimens in which a distal UCL tear was simulated were included. UCL reconstruction with suture tape augmentation (AugRecon) restored load to failure to a statistically noninferior magnitude (mean difference [MD], -1.99 N·m; 95% CI, -10.2 to 6.2 N·m; P = .63) compared with the native UCL. UCL reconstruction (Recon) (MD, -12.7 N·m; P < .001) and UCL repair with suture tape augmentation (AugRepair) (MD, -14.8 N·m; P < .001) were both statistically inferior to the native UCL. The AugRecon condition conferred greater load to failure compared with Recon (P < .001) and AugRepair (P = .002) conditions. AugRecon conferred greater torsional stiffness relative to all other conditions and was not statistically different from the native UCL (MD, 0.32 N·m/deg; 95% CI, -0.30 to 0.95 N·m/deg; P = .31). Medial ulnohumeral gapping was not statistically different for the AugRepair (MD, 0.30 mm; 95% CI, -1.22 to 1.82 mm; P = .70), AugRecon (MD, 0.57 mm; 95% CI, -0.70 to 1.84 mm; P = .38), or Recon (MD, 1.02 mm; 95% CI, -0.02 to 2.05 mm; P = .055) conditions compared with the native UCL. P-score analysis indicated that AugRecon was the most effective treatment for increasing ultimate load to failure and torsional stiffness, whereas AugRepair was the most effective for minimizing medial gapping. CONCLUSION: AugRecon restored load to failure and torsional stiffness most similar to the parameters of the native UCL, whereas Recon and AugRepair did not restore the same advantageous properties at time zero. Medial ulnohumeral gapping during a valgus load was minimized by all 3 treatments. Based on network interactions, AugRecon was the superior treatment approach for restoring important biomechanical features of the UCL at time zero that are jeopardized during a complete distal tear.

Association of Head-Neck Rotation With History of Pitching-Related Elbow Pain in Youth Baseball Players.

Background: Prevention of pitching-related elbow pain in youth baseball players is important. Overhead pitching involves a whole-body motion, including head-neck rotation. A limited range of motion of head-neck rotation may cause inefficient pitching motion; however, this association is unclear. Purpose: To determine whether the range of motion of head-neck rotation is associated with the history of pitching-related elbow pain in youth baseball players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 311 youth baseball players were selected and asked to complete a questionnaire survey about their age, weight, height, sex, baseball experience, main position, pitching side, and previous/current elbow pain during pitching. The range of motion of the upper and lower limb joints, head-neck rotation, and thoracic kyphosis angle were measured. Binomial logistic regression analysis was used to identify factors associated with the history of elbow pain related to pitching. Results: There were 101 players with a history of pitching-related elbow pain (history group) and 142 players with no pitching-related elbow pain (no-history group). The history group had significantly lower values than the no-history group regarding the range of motion of head-neck rotation on the nondominant side (74.9°± 9° vs 77.7°± 9.6°; P = .02) and overall head-neck rotation (150.6°± 14.7° vs 154.9°± 18.4°; P = .04). Binomial logistic regression analysis identified head-neck rotation on the nondominant side (odds ratio [OR], 0.97 [95% CI, 0.94-1.00]), shoulder horizontal adduction on the dominant side (OR, 0.98 [95% CI, 0.96-1.00]), height (OR, 1.04 [95% CI, 1.00-1.08]), and playing position (pitcher) (OR, 0.40 [95% CI, 0.21-0.76]) as factors associated with a history of pitching-related elbow pain. Conclusion: Our cross-sectional analysis demonstrated that youth baseball players with a history of pitching-related elbow pain had limited head-neck rotation range of motion on the nondominant side, and this was a significant factor associated with the history of pitching-related elbow pain.