Are the Current Little League Pitching Guidelines Adequate? A Single-Season Prospective MRI Study

Youth Pitcher Fatigue: Medial Elbow Laxity, Ultrasonographic Assessment of Flexor-Pronator Mass Energy Depletion, and Association With Pitch Count

Background

Ulnar collateral ligament (UCL) injuries in youth pitchers continue to be concerning despite the institution of pitch count limits. Flexor-pronator mass fatigue can lead to diminished dynamic stability, resulting in greater stress on the UCL.

Purpose/Hypothesis

To evaluate fatigue of the flexor-pronator mass by assessing changes in medial elbow laxity; noninvasively characterizing alterations in muscle glycogen; and identifying changes in subjective fatigue, strength, range of motion (ROM), pitching velocity, and accuracy with increasing pitches thrown by youth pitchers to their recommended 75-pitch count limit. It was hypothesized that, with increased pitches, medial elbow laxity would increase and that the glycogen content of the flexor-pronator mass would decrease.

Study Design

Descriptive laboratory study.

Methods

Healthy male pitchers aged 10 years (n = 22) threw 3 sets of 25 pitches with 12 minutes between sets (3 timepoints). Bilateral ulnohumeral joint gapping was measured by applying a standardized valgus force and utilizing ultrasound imaging. Relative changes in muscle glycogen in the bilateral flexor carpi radialis (FCR), and the flexor digitorum superficialis/flexor carpi ulnaris (FDS/FCU) muscles were measured with ultrasound software and recorded as fuel percentiles. Additional measures obtained included subjective fatigue, strength, ROM, velocity, and accuracy.

Results

There were no differences in medial elbow joint-line gapping between the throwing and nonthrowing arms or between timepoints. The throwing arm demonstrated a significant decline in fuel percentile of the FCR from baseline to after 75 pitches (P = .05). There were no differences across timepoints for FDS/FCU fuel percentile values. Fatigue measurements for both arms were significantly higher at all timepoints compared with baseline (P≤ .03). Grip strength of the dominant arm after 75 pitches was decreased significantly compared with after 25 pitches (P = .02).

Conclusion

Although an increase in medial elbow joint gapping was not demonstrated within the recommended 75 pitch count limit in 10-year-olds, a relative decrease in glycogen stores of the flexor-pronator mass did occur, as well as a decrease in grip strength, with increasing subjective fatigue.

Clinical Relevance

This study provides a foundation for further objective testing of physiologic changes that occur with pitching to better guide pitch count limits and improve the safety of young athletes.

Pediatric thrower's elbow: maturation-dependent MRI findings in symptomatic baseball players

BACKGROUND

Elbow pain is common among youth baseball players and elbow MRI is increasingly utilized to complement the clinical assessment.

OBJECTIVE

To characterize, according to skeletal maturity, findings on elbow MRI from symptomatic youth baseball players.

MATERIALS AND METHODS

This IRB-approved, HIPAA-compliant retrospective study included pediatric (<18 years of age) baseball players with elbow pain who underwent MRI examinations between 2010 and 2021. Two radiologists, blinded to the outcome, independently reviewed examinations to categorize skeletal maturity and to identify osseous and soft tissue findings with consensus used to resolve discrepancies. Findings were compared between skeletally immature and mature patients and logistic regression models identified predictors of surgery.

RESULTS

This study included 130 children (115 boys, 15 girls): 85 skeletally immature and 45 mature (12.8±2.3 and 16.2±1.0 years, respectively, p<0.01). Kappa coefficient for interobserver agreement on MRI findings ranged from 0.64 to 0.96. Skeletally immature children, when compared to mature children, were more likely to have elbow effusion (27%, 23/85 vs 9%, 4/45; p=0.03), medial epicondyle marrow edema (53%, 45/85 vs 16%, 7/45; p<0.01), avulsion fracture (19%, 16/85 vs 2%, 1/45; p=0.02), and juvenile osteochondritis dissecans (OCD, 22%, 19/85 vs 7%, 3/45; p=0.04), whereas skeletally mature children were more likely to have sublime tubercle marrow edema (49%, 22/45 vs 11%, 9/85; p<0.01) and triceps tendinosis (40%, 18/45 vs 20%, 17/85; p=0.03). Intra-articular body (OR=4.2, 95% CI 1.5-47.8, p=0.02) and osteochondritis dissecans (OR=3.7, 95% CI 1.1-11.9, p=0.03) were independent predictors for surgery.

CONCLUSION

Differential patterns of elbow MRI findings were observed among symptomatic pediatric baseball players based on regional skeletal maturity. Intra-articular body and osteochondritis dissecans were independent predictors of surgery.

Characteristics Associated With Noncompliance of Current Pitch Smart Guidelines in High School Baseball Pitchers Throughout the United States

Background

Although pitch count and rest guidelines have been promoted for youth and adolescent baseball players for nearly 2 decades, compliance with guidelines remains poorly understood.

Purpose/Hypothesis

The purpose of this study was to determine the frequency of compliance with Major League Baseball (MLB) Pitch Smart guidelines as well as the association between compliance and range of motion (ROM), strength, velocity, injury, and pitcher utilization. It was hypothesized that pitchers in violation of current recommendations would have increased strength, velocity, and injury.

Study Design

Case-control study; Level of evidence, 3.

Methods

This was a prospective, multicenter study of 115 high school pitchers throughout the United States. Pitchers were surveyed about their compliance with current off-season, rest-related guidelines, and history of injury. During the preseason, pitchers underwent standardized physical examinations, and pitch velocity was measured. Pitch counts were collected during the baseball season that followed. Dynamometer strength testing of shoulder forward flexion, and external rotation as well as grip strength was recorded. We compared pitchers who were compliant with recommendations with those who were noncompliant using Student t and Mann-Whitney U tests.

Results

Based on preseason data, 84% of pitchers had violated current Pitch Smart guidelines. During the season, 14% had at least 1 violation of the Pitch Smart guidelines. Across both the preseason survey and in-season pitch counts, 89% of players had at least 1 violation of the Pitch Smart guidelines. While there were no significant differences in ROM or strength, the noncompliant group had higher maximum pitch velocity than the compliant group (74 ± 8 vs 69 ± 5 mph [119 ± 13 vs 111 ± 8 kph], respectively; P = .009). Players' self-reported velocity differed significantly from the direct measurement, for both peak velocity (80 ± 6 vs 73 ± 8 mph [129 ± 9 vs 117 ± 13 kph], respectively; P < .001) and mean velocity (73 ± 8 vs 53 ± 27 mph [117 ± 13 vs 85 ± 43 kph], respectively; P < .001).

Conclusion

Most high school pitchers were not fully compliant with current Pitch Smart guidelines, and they tended to overestimate their peak velocity by 7 mph (11 kph). Pitchers who threw with greater velocity were at higher risk for violating Pitch Smart recommendations.

Early Sport Specialization and Long-term Throwing Arm Health in College Baseball Players

BACKGROUND

Early sport specialization is associated with increased risk of overuse injuries in several sports, including baseball. However, limited evidence exists evaluating how early sport specialization affects patient-reported outcome measures as they age. The purpose of this study was to determine differences in Kerlan-Jobe Orthopedic Clinic (KJOC) Shoulder and Elbow Scores among collegiate baseball players based on the grade when a participant first reported high specialization behaviors.

HYPOTHESIS

Baseball players who were highly specialized at a younger age will have worse throwing arm health while participating in college.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 752 college baseball players was contacted through their institution's athletic trainer. We measured baseball specialization and KJOC scores using the validated Baseball and Sport Experience survey. Data were summarized using means and SDs, medians and interquartile ranges (IQRs), and frequencies and percentages. A Kruskal-Wallis test was used to determine differences in mean KJOC scale scores based on the earliest time the participant reported high-level specialization.

RESULTS

A total of 294 baseball players completed the survey (response rate: 39.1%). Of the 294 participants, 280 completed the KJOC scale questions to generate a total KJOC score (median: 90.5; IQR: 76.6-97.2). No significant differences in KJOC total scores (P = 0.78) existed based on the grade period in which the athlete was first highly specialized.

CONCLUSION

Early baseball specialization as a youth baseball player may not impact throwing arm health in college baseball athletes.

CLINICAL RELEVANCE

Early specialization has been linked to increased risk for overuse injuries in certain sports, but may not lead to poorer throwing arm health in college baseball players. Sports medicine clinicians and researchers may use this information to educate various stakeholders about the benefits and risks associated with early sport specialization.

Increased Medial Elbow Torque Is Associated With Ball Velocity Rather Than a History of Medial Elbow Injuries in Youth Baseball Pitchers

PURPOSE

This study compared medial elbow torque in youth baseball pitchers with and without a history of medial elbow injuries to determine the relationship between medial elbow torque during pitching and having a history of medial elbow injuries.

METHODS

We recruited 171 youth baseball pitchers aged 9 to 12 years old. The exclusion criteria included current pain with pitching, history of surgery on the tested extremity, or osteochondritis dissecans of the humeral capitellum. The participants were grouped into 3 groups: injury <1-year, injury >1-year, and control, based on ultrasonographic abnormalities of the elbow and the presence of elbow pain. Pitchers pitched 3 fastballs while wearing a sensor sleeve that recorded the medial elbow torque, arm speed, and shoulder rotation. Ball velocity was measured using a radar gun.

RESULTS

The final analysis included 164 pitchers. Thirty were assigned to the injury <1-year group, 34 to the injury >1-year group, and 100 to the control group. The medial elbow torque was significantly greater in the injury <1-year group compared with the control group (18.6 ± 3.6 Nm vs 16.2 ± 4.8 Nm, P = .023). A multiple regression analysis revealed that ball velocity (B = 0.282, P < .001) and body weight (B = -0.224, P < .001) were significantly associated with medial elbow torque, but not with the history of medial elbow injuries.

CONCLUSIONS

Increased medial elbow torque was associated with greater ball velocity regardless of the history of medial elbow injuries. Youth baseball pitchers with a history of medial elbow injuries within one year had greater medial elbow torque during pitching; however, having a history of medial elbow injuries was not an independent factor in increasing medial elbow torque. Limiting the ball velocity can reduce medial elbow torque and may prevent elbow injuries in youth baseball pitchers.

LEVEL OF EVIDENCE

Level II, prospective comparative prognostic investigation with the patients enrolled at different time point.

High-definition magnetic resonance images on medial elbow injuries in preadolescent Little Leaguers

BACKGROUND

The incidence of throwing-related elbow injuries is still rising. The study aimed to enhance the pathology of acute medial elbow injuries among young Little Leaguers by examining the medial elbows of symptomatic 9-10 years old Little Leaguers using High-Definition Magnetic Resonance Images (HDMRI), which uses a small-diameter surface coil on the target area, leading to greater image resolution.

METHOD

We identified Little Leaguers aged 9-10 years old. To minimize the detection of the chronic adaptative changes, players who experienced the medial elbow pain previously and whose HDMRI had not been taken within 4 weeks from the onset of medial elbow pain were excluded. This study considered 21 players, and the mean age was 9.4 ± 0.5 years.

RESULT

The fragmentation of the medial epicondyle apophysis via HDMRI was found in 15 elbows (71.4%), while the avulsion was seen in three cases. The signal hyperintensity at the medial epicondyle apophysis was observed in 2 cases. Our data showed abnormal changes to the medial epicondyle apophysis and surrounding structures, such as the ulnar collateral ligament (UCL), flexor-pronator tendons or the coronoid process of the ulna. We detected 11 abnormalities on X-ray imaging, while 20 subjects showed some abnormal findings via HDMRI.

DISCUSSION

The current study showed that initial medial elbow injury in Little Leaguers without a history of previous elbow injury could be attributed to multi-structure injury. Over 90% of subjects were injured in the perichondrium, while 71.4% demonstrated a fragmentation of the secondary ossification center, and 14.3% experienced an avulsion of the medial epicondyle apophysis. Because the injuries were not limited to bony structures, HDMRI may be beneficial for the appropriate evaluation of medial elbow pain. The pathology of initial medial elbow injuries in young baseball players may be due to acute trauma instead of repetitive microtrauma.

Attitudes and beliefs of little league baseball parents regarding sport specialization and college scholarship availability

OBJECTIVES

Previous studies of parents of adolescent athletes identified a belief among parents of the importance of early specialization for skill development. However, it is unclear if these attitudes and beliefs are also held among parents of baseball athletes, which is the second-most popular boy's sport in the United States. The purpose of this study was to describe the knowledge, attitudes, and beliefs of parents of Little League baseball players regarding sport specialization and college scholarships.

METHODS

Two-hundred and forty-four parents of Little League baseball players (female parents: 60.7%, parent age: 41.1 ± 6.2 years old, male children: 98.0%, child age: 9.5 ± 1.6 years old) completed an anonymous online questionnaire regarding parent attitudes and beliefs on sport specialization and college scholarships.

RESULTS

Most parents (72.4%) felt that specialization would increase their child's baseball ability either 'quite a bit' or 'a great deal.' Fewer than half of all parents (42.0%) reported that specialization was either 'quite a bit' or 'a great deal' of a problem. Parents underestimated the availability of Division I college baseball scholarship availability (median [IQR]: 5 [4-10]), compared to the actual value of 11.7 scholarships per Division I roster. Only 10.2% of parents (N = 25) reported that they believed it was 'somewhat' or 'very' likely that their child would receive a college baseball scholarship.

CONCLUSION

Further efforts are needed to understand parent attitudes and beliefs regarding sport specialization and college scholarships in various sports to better understand current trends in youth sport participation.

Youth throwing athletes do not show bilateral differences in medial elbow width or flexor tendon thickness

Background

Medial elbow laxity develops in throwing athletes due to valgus forces. Medial elbow instability in professional, collegiate, and high school athletes is well documented; however, the medial elbow of young throwing athletes has received less attention. This study investigated the medial elbow and common flexor tendon during applied elbow valgus stress of youth baseball players.

Methods

The study included 15 participants. The medial elbow width and thickness of the common flexor tendon were measured on ultrasound images.

Results

No significant side differences in medial elbow width or common flexor tendon were found at rest or under applied valgus stress. At rest, the medial elbow joint width was 3.34±0.94 mm on the dominant side and 3.42±0.86 mm on the non-dominant side. The dominant side increased to 3.83±1.02 mm with applied valgus stress, and the non-dominant side increased to 3.96±1.04 mm. The mean flexor tendon thickness was 3.89±0.63 mm on the dominant side and 4.02±0.70 mm on the non-dominant side.

Conclusions

These findings differ from similar studies in older throwing athletes, likely because of the lack of accumulated stress on the medial elbow of youth throwing athletes. Maintaining elbow stability in young throwing athletes is a vital step to preventing injury later in their careers.

Athletes Perceive Weighted Baseballs to Carry a Notable Injury Risk, yet Still Use Them Frequently: A Multicenter Survey Study

Weighted baseball use in throwing programs is widespread; however, their use remains controversial. Prior research shows that weighted baseball programs can increase ball velocity but potentially increase throwing arm injuries. This study aims to ascertain perceptions of weighted baseballs among elite baseball players.

Common Upper Extremity Injuries in Pediatric Athletes

PURPOSE OF REVIEW

The aim of this study is to review the most recent literature on common upper extremity injuries in pediatric athletes and discuss their diagnosis, management, and outcomes. We also highlight ultrasound as a tool in their evaluation.

RECENT FINDINGS

Shoulder conditions presented include little league shoulder, glenohumeral rotation deficit, acute traumatic shoulder dislocation, and multidirectional shoulder instability. Elbow conditions include capitellar OCD, medial epicondyle avulsion fracture, and medial epicondylitis. We also review scaphoid fractures and gymnast wrist. Not all physeal injuries lead to long-term growth disruption. Ultrasound has been shown to be useful in the diagnosis of scaphoid fracture, medial epicondyle avulsion fractures, and capitellar OCD. It can also be helpful in assessing risk for shoulder and elbow injuries in overhead athletes. There is a rising burden of upper extremity injuries among pediatric athletes. Knowledge of their sport specific mechanics can be helpful in diagnosis. As long-term outcome data become available for these conditions, it is clear, proper diagnosis and management are critical to preventing adverse outcomes. We highlight many of these injuries, best practice in care, and controversies in care in hopes of improving outcomes and preventing injury for pediatric athletes.

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

Background:

Studies have shown that higher pitch counts are directly related to a greater incidence of elbow and shoulder pain among youth baseball pitchers.

Purpose/Hypothesis:

The purpose of this study was to examine the effect of different pitching restriction rules on the number of pitches thrown in youth baseball leagues. We hypothesized that more pitches would be thrown in leagues with inning restrictions versus leagues with pitch count restrictions as well as in leagues with a longer mound distance (from pitching mound to home plate).

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Pitch count data were collected for 2 consecutive years over a 10-week season from 3 different leagues of 9- to 12-year-old baseball players in a single city. The Eastern league had a pitch count restriction and 46-ft (14.02-m) mound distance. The Southeastern and South leagues’ pitching restrictions were based on innings per week. The Southeastern league had a 50-ft (15.24-m) mound distance, while the South league had a 46-ft mound distance. Comparisons of total seasonal pitches thrown were made of the 3 highest-volume pitchers on each team. League averages for each value were then compared utilizing analysis of variance with Bonferroni post hoc analysis. The number of pitchers in each league who threw >600 pitches per season was compared using the chi-square test.

Results:

No significant difference in seasonal pitch counts or innings pitched was noted between the Eastern and South leagues, which differed only in their pitching restrictions. The Southeastern league, with a longer mound distance, was found to have higher seasonal pitch counts per thrower (598 ± 195 pitches) than the South league (463 ± 198 pitches) for the 3 highest-volume throwers for each team (P = .004). The Southeastern league also had a significantly larger number of pitchers who threw >600 pitches per season (33 vs 20 for Eastern and 13 for South; P = .009).

Conclusion:

There was no significant difference in seasonal pitch counts when the leagues in this study differed based on pitching restrictions. However, the league with a greater mound distance (Southeastern) had higher seasonal pitch counts for the highest-volume throwers. Pitching restrictions based on pitch counts, as opposed to innings, may be advisable.

Risk factor for elbow symptom manifestation in young baseball players with asymptomatic medial elbow abnormalities: a prospective cohort study

Asymptomatic elbow abnormalities are relatively common in young baseball players, but the factors responsible are unclear. To prospectively identify risk factors related to symptom manifestation in asymptomatic elbow abnormalities, we recruited 573 baseball players (age: 7-14 years) at a pre-participation medical/physical examination in the preseason who were right-handed and had asymptomatic medial elbow abnormalities on ultrasound (US). Baseline preseason and postseason participant characteristics were assessed. A "symptomatic" elbow was defined as an elbow with medial elbow joint problems that prevented ball throwing for ≥ 8 days. After exclusions, 82 players were enrolled, of whom 22 (26.8%) developed a symptomatic elbow. In univariate analyses, the external and internal rotation strengths of the dominant shoulder were significantly greater in the symptomatic group than in the asymptomatic group (P = 0.021). Multivariate logistic regression analysis showed that the internal rotation strength of the dominant shoulder was a significant independent risk factor (odds ratio = 1.091, P = 0.027) for developing a symptomatic elbow. In young asymptomatic baseball players with abnormalities in the medial elbow region of the dominant arm on US, stronger preseason internal rotation strength of the dominant shoulder was a significant independent risk factor for the development of a "symptomatic" elbow.

The association of sport participation behaviors with throwing-arm health in Little League Baseball pitchers

Background and Hypothesis

There is increasing concern about the role sport specialization might play in the increasing injury rates observed among youth baseball pitchers. However, existing research on specialization in baseball has focused on high school and professional baseball populations. We hypothesized that pitchers who were highly specialized, reported pitching more than eight months in the past year, received private coaching, or pitched with pain or fatigue in the previous year would report worse throwing-arm health.

Methods

One-hundred eighty-four Little League pitchers (boys N = 181, age 9.8 ± 1.6 years old) between 7 and 12 years of age completed an anonymous, online questionnaire with their parents' assistance. The questionnaire consisted of participant demographics, sport specialization status, months of pitching per year, whether they traveled regularly to participate in showcases, if they received private coaching, whether they pitched with elbow or shoulder pain, whether they pitched with fatigue, and the Youth Throwing Score (YTS), a valid and reliable patient-reported outcome measure for youth baseball players. The associations between variables of interest and YTS were examined using multivariable linear regression, adjusting for covariates.

Results

Sport specialization, pitching year-round, and receiving private coaching were not associated with the YTS (P > .05). Pitching with pain in the previous year was associated with a worse YTS score than pitching without pain (least square mean [standard error]: 49.6 [1.8] vs. 57.8 [1.1], P < .001). Similarly, pitching with fatigue in the previous year was associated with worse YTS scores (least square mean [standard error]: 52.1 [1.4] vs. 55.3 [1.3], P = .01). Pitchers who reported traveling regularly for showcases scored worse on the YTS compared with those who did not travel regularly for showcase events (least square mean [standard error]: 51.0 [2.0] vs. 56.4 [0.9], P = .01).

Conclusions

Pitching with pain or fatigue was associated with worse throwing-arm health in Little League baseball pitchers. While traveling at least once a month to participate in showcases was also associated with worse throwing-arm health, specialization and private coaching were not related to worse throwing health. Clinicians working with pediatric patient populations should be aware that while the factors examined in this article were reported relatively infrequently, screening for Little League pitchers who participate in showcases or pitch with pain or fatigue may be an effective strategy for identifying these individuals who are at higher risk of injury.

Asymptomatic Medial Elbow Ultrasound Abnormality in Youth Baseball Players Is an Independent Risk Factor for Elbow Injury: A Prospective Cohort Study

Background

Youth baseball players who experience elbow pain during the season frequently exhibit radiographic elbow abnormalities. However, it is unknown whether asymptomatic elbow abnormalities are risk factors for in-season elbow injuries.

Purpose

To determine whether the preseason presence of asymptomatic medial epicondyle apophysitis is a risk factor for in-season elbow injuries in youth baseball players.

Study Design

Cohort study; Level of evidence, 2.

Methods

Youth baseball players (N = 210; age range, 7-12 years) with no pain or history of injury in their throwing arms underwent preseason evaluations that included shoulder and elbow range of motion measurements, shoulder muscle strength testing, and ultrasound elbow scans with a multifrequency 13-MHz linear array transducer. Over 1 year of play, the players and their parents maintained daily elbow pain diaries. Elbow injuries were defined as medial elbow symptoms that prevented ball throwing for ≥8 days.

Results

The preseason ultrasound evaluation revealed medial epicondyle apophysitis in 59 players. In the year following, elbow injuries occurred in 17 (28.8%) players with preseason medial epicondyle apophysitis and 18 (11.9%) players without apophysitis. Independent predictors of elbow injuries were preseason medial epicondyle apophysitis (odds ratio [OR], 2.488; 95% confidence interval [CI], 1.152-5.376; P = .02) and deficits of abduction (ABD) and external rotation of the dominant shoulder (OR, 0.963; 95% CI, 0.936-0.992; P = .012).

Conclusion

Asymptomatic medial epicondyle apophysitis and ABD and external rotation deficits in the dominant shoulder were risk factors for elbow injuries in 7- to 12-year-old youth baseball players. These findings may aid in the design of programs to prevent elbow injuries in this population.

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.

Early Sport Specialization Linked to Throwing Arm Function and Upper Extremity Injury History in College Baseball Players

BACKGROUND

Evidence suggests that shoulder and elbow injuries account for 31% to 37% of all National Collegiate Athletic Association (NCAA) baseball injuries, and up to 69% of NCAA baseball injuries are the result of noncontact and overuse mechanisms. Early sport specialization may contribute to the high rates of upper extremity injuries in college baseball players.

HYPOTHESIS

Higher specialization by age 13 years would be associated with worse subjective throwing arm function and a greater history of shoulder and elbow injury.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level 2.

METHODS

Survey data were collected from college baseball players (N = 129) during midseason of the spring 2019 baseball season. Participants were stratified in low, moderate, and high specialization groups based on a 3-criteria sports specialization questionnaire. Participants' throwing arm function was measured using the Functional Arm Scale for Throwers and the Kerlan-Jobe Orthopaedic Clinic shoulder and elbow questionnaires. Participants' history of a shoulder or elbow injury that resulted in missing ≥2 weeks of baseball activity at any point in their baseball career was also collected.

RESULTS

The high specialization group reported worse subjective throwing arm function on the Functional Arm Scale for Throwers questionnaire than the low (P = 0.03) and moderate (P = 0.01) specialization groups. The high specialization group was over 5 times more likely to report a history of shoulder injury than the moderate (odds ratio [OR] = 5.42; 95% CI [1.71, 17.2]; P = 0.004) and low (OR = 5.20; 95% CI [1.87, 14.5]; P = 0.002) specialization groups, and over 3 times more likely to report a history of elbow injury than the moderate specialization group (OR = 3.77; 95% CI [1.05, 13.6]; P = 0.04).

CONCLUSION

College baseball players that were highly specialized by age 13 years reported worse subjective throwing arm function and were more likely to have a history of upper extremity injury than players that were moderate or low specialization.

CLINICAL RELEVANCE

Early specialization in baseball may be detrimental to long-term upper extremity health in college baseball players.

The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program

BACKGROUND

Postoperative rehabilitation protocols after ulnar collateral ligament (UCL) reconstruction typically involve a structured interval throwing program. In an effort to minimize torque placed on the UCL, athletes are often instructed to throw with a crow hop, even at short throwing distances. However, the effect of the crow hop on medial elbow stress is unknown.

PURPOSE/HYPOTHESIS

The purpose was to determine whether elbow stress differs with and without a crow hop across the throwing distances of a typical interval throwing program. We hypothesized that crow hop throws would generate lower torque on the elbow than standing throws at each distance of the interval throwing program.

STUDY DESIGN

Controlled laboratory study.

METHODS

Healthy high school and collegiate pitchers and position players were recruited from the surrounding area. Each player was outfitted with a wearable athletic sleeve and device that recorded elbow torque (Newton-meters), arm slot (degrees), arm speed (revolutions per minute), and shoulder rotation (degrees). Ball velocity (miles per hour) was measured using a radar gun. Players were instructed to perform 3 crow hop throws and 3 standing throws at distances of 30, 45, 60, 90, 120, 150, and 180 feet. A repeated measures analysis of variance was used to compare ball velocity, elbow torque, arm slot, arm speed, and shoulder rotation between crow hop and standing throws at each throwing distance.

RESULTS

Twenty athletes participated in this study (average age, 17.8 years; range, 15-25 years). The average medial elbow torque increased at each distance for both crow hop and standing throws at distances of 30, 45, 60, and 90 feet (P < .05), after which there were no significant increases in elbow torque (P > .05). The average torque was higher for crow hop throws than standing throws at distances of 30 feet (13.9 N·m vs 12.0 N·m; P = .002), 45 feet (21.8 N·m vs 19.3 N·m; P = .005), and 60 feet (28.0 N·m vs 24.5 N·m; P = .02).

CONCLUSION

Crow hop throws generated greater medial elbow torque than standing throws at distances up to 60 feet; however, there were no differences in elbow torque at distances greater than 60 feet between the 2 throw types. For both crow hop and standing throws, elbow stress increased at each distance interval up to 90 feet before plateauing at distances greater than 90 feet. The crow hop throwing technique does not reduce medial elbow stress during a simulated interval throwing program, and it may actually increase torque at shorter throwing distances.

CLINICAL RELEVANCE

The results of our study indicate that it would be prudent for players to initially perform standing throws at shorter distances and only later be allowed to employ a natural crow hop at greater distances to minimize torque placed on the medial elbow during UCL rehabilitation protocols.

Current Concepts in Arm Care Exercise Programs and Injury Risk Reduction in Adolescent Baseball Players: A Clinical Review

CONTEXT

Awareness of important injury risk factors associated with excessive pitching volume has been highlighted in the literature, but injury rates remain high. Shoulder pain in baseball players is associated with various changes in musculoskeletal movements, which presents as measurable impairments throughout the kinetic chain. Baseball coaches and rehabilitation professionals have utilized exercise programs targeting strength and flexibility of the throwing arm to prevent injuries. The purpose of this review is to summarize the current evidence regarding the effectiveness of arm care exercise programs in reducing upper extremity injury rates in adolescent baseball players.

EVIDENCE ACQUISITION

A search of electronic databases, including CINAHL with full text, MEDLINE, and SPORTDiscus was conducted to retrieve available articles in English from the years 2010 through 2020. The search terms injury prevention, exercise, and adolescent baseball were used.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Improving shoulder internal rotation range of motion by stretching the posterior shoulder muscles daily was associated with a 36% risk reduction of shoulder and elbow injuries. Group-based arm care exercise programs that target multiple musculoskeletal impairments demonstrated an approximately 50% reduced risk of elbow injury.

CONCLUSION

For adolescent baseball players, arm care injury prevention programs focusing on important musculoskeletal impairments are effective at reducing injury incidence rates. Multimodal injury prevention programs that improve multiple musculoskeletal impairments are more comprehensive and may result in better injury reduction than programs focusing on a singular impairment.

Sport specialization is associated with upper-extremity overuse injury in high school baseball players

BACKGROUND AND HYPOTHESIS

Sport specialization is increasingly common in youth sports and is a risk factor for lower-extremity overuse injuries. However, limited data exist on whether specialization is associated with upper-extremity (UE) overuse injuries, specifically in youth baseball players. We hypothesized that specialization in baseball and being a pitcher would be associated with poorer arm health and UE overuse injury history in the previous year.

METHODS

During the 2019 spring baseball season, 551 high school baseball athletes (aged 15.9 ± 1.3 years) from 3 states (Alabama, n = 200; California, n = 188; and Michigan, n = 163) completed an anonymous questionnaire. Athletes were recruited from 5 high schools in each state, with schools matched based on factors that influence specialization rates. The questionnaire consisted of (1) demographic characteristics, (2) baseball participation information (including sport specialization status), and (3) throwing-arm health and UE injury history in the previous 12 months. Throwing-arm health was assessed using the Youth Throwing Score (YTS), a validated and reliable outcome measure for youth baseball players. Multivariate regression analyses were used to examine the association between variables of interest and the YTS or UE overuse injury history, adjusting for covariates.

RESULTS

After adjustment for covariates, highly specialized athletes were more likely to report a UE overuse injury in the previous year compared with low-specialization athletes (odds ratio [OR], 3.77; 95% confidence interval [CI], 1.39-10.2, P = .009). Both athletes who reported playing baseball for more than 8 months per year (OR, 2.03; 95% CI, 1.12-3.65; P = .019) and athletes who reported being a pitcher (OR, 2.11; 95% CI, 1.20-3.72; P = .010) were more likely to report a history of UE overuse injury. Highly specialized players reported lower (worse) YTS values compared with low-specialization players (least-squares mean estimate ± standard error, 56.5 ± 1.1 vs. 53.3 ± 0.7; P = .034). Players who reported pitching as one of their positions scored worse on the YTS than non-pitchers (least-squares mean estimate ± standard error, 51.6 ± 0.8 vs. 57.2 ± 0.6; P < .001).

CONCLUSION

Although baseball recommendations that discourage sport specialization are widely available for parents, athletes, and coaches, high rates of sport specialization were reported in our sample. We found that being highly specialized in baseball was associated with UE overuse injury history and worse throwing-arm health in high school baseball athletes. Continued education for baseball parents, athletes, and coaches is necessary to raise awareness of the risks associated with high specialization.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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 OF EVIDENCE

Level IV.

Primary Repair of Proximal Ulnar Collateral Ligament Ruptures in Pediatric Overhead Athletes

Ulnar collateral ligament (UCL) injury is commonly seen in overhead throwing athletes resulting from the repetitive valgus stress placed on the medial elbow. UCL injuries (attenuation, insufficiency, or rupture) can result in medial elbow pain, a loss of pitch velocity and accuracy, and increased fatigue. Diagnosis can be made by performing a thorough physical examination along with imaging if indicated, such as ultrasound or magnetic resonance imaging. Treatment options include nonoperative in recreational athletes or those whose primary positions in sport are not high-volume throwing, such as position players in baseball. If nonoperative treatment fails, or the patient has potential for future high-level overhead activity such as a baseball pitcher, surgical repair or reconstruction may be indicated. This article describes our surgical technique for UCL repair in pediatric baseball pitchers.

Injuries and associated risk factors of the shoulder and elbow among adolescent baseball pitchers: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study was to perform a systematic review and meta-analysis of the current literature surrounding risk factors associated with shoulder and elbow injuries among adolescent baseball pitchers.

METHODS

Relevant studies were assessed for inclusion and retained from PubMed, EMBASE, SportDiscus, and CINAHL databases. Data was extracted from the retained studies and underwent methodological quality assessment and meta-analysis.

RESULTS

The search resulted in 1238 studies identified with 10 ultimately retained for systematic review. Five studies including one case-control, two prospective cohort, and two cross-sectional studies met inclusion criteria for meta-analysis. This meta-analysis revealed that playing with arm fatigue was a significant risk factor (pooled odds ratio = 13.32, 95% confidence interval: 3.22-55.09). The other three risk factors (long competitive season, pitching for more than one team or league, and playing catcher as a secondary position) were not statistically significant.

CONCLUSION

Pitching with arm fatigue is a significant risk factor for shoulder and elbow injuries among adolescent baseball pitchers. Future efforts in assessment and mitigation of pitching with arm fatigue among this population may help to reduce the risk of arm injuries. Furthermore, investigations of additional risk factors in a more homogeneous population of adolescent pitchers may be warranted.

Progressive Elbow Magnetic Resonance Imaging Abnormalities in Little League Baseball Players Are Common: A 3-Year Longitudinal Evaluation

BACKGROUND

Prior studies have revealed magnetic resonance imaging (MRI) evidence of elbow pathology in single-season evaluation of competitive youth baseball players. The natural history of these findings and risk factors for progression have not been reported.

PURPOSE

To characterize the natural history of bilateral elbow MRI findings in a 3-year longitudinal study and to correlate abnormalities with prior MRI findings, throwing history, playing status, and physical examination.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A prospective study of Little League players aged 12 to 15 years was performed. All players had preseason and postseason bilateral elbow MRI performed 3 years before this study. Players underwent repeat bilateral elbow MRI, physical examination, and detailed assessment of throwing history, playing status, and arm pain. Imaging was read by a blinded musculoskeletal radiologist and compared with prior MR images to assess for progression or resolution of previously identified pathology.

RESULTS

All 26 players who participated in the previous single-season study returned for a 3-year assessment. At the completion of the study, 15 players (58%) had dominant arm MRI pathology. Eighty percent (12/15 players) of MRI findings were new or progressive lesions. Players with postseason MRI pathology at the beginning of the study were more likely to have MRI pathology at the 3-year follow-up than players with previously normal postseason MRI (P < .05), although 6 of the 14 players (43%) with previously normal MRI developed new pathology. Year-round play was a significant predictor of tenderness to elbow palpation (P = .027) and positive MRI findings at 3 years (P = .047). At the 3-year follow-up, 7 players (27%) reported having throwing elbow pain and 3 had required casting. Additionally, differences were noted in the dominant arm's internal and external rotation in those that continued to play baseball (P < .05).

CONCLUSION

Dominant elbow MRI abnormalities are common in competitive Little League Baseball players. Year-round play imparts significant risk for progression of MRI pathology and physical examination abnormalities.

Sport Specialization and Overuse Injuries in Adolescent Throwing Athletes: A Narrative Review

A significant number of adolescent athletes throughout the world participate in various throwing-dominant sports, including but not limited to baseball, cricket, handball, softball, track and field throwing events, and water polo. Due to the unique stresses placed on the throwing arm and entire body in these sports, a robust volume of literature has highlighted concerns about sport specialization in these athletes and an associated increased risk of injury, particularly to the dominant shoulder and elbow, with sport specialization. This review will highlight the evidence-based literature for this athletic niche, focusing on risk factors for injury, national and international organizations' recommendations for limiting overuse injuries, principles of conditioning and rehabilitative programs, and potential future areas of research to curb the growing incidence of throwing-related injuries among adolescent throwing athletes.

The Curse of the All-Star Team: A Single-Season Prospective Shoulder MRI Study of Little League Baseball Players

BACKGROUND

Throwing guidelines have been implemented in Little League baseball in an attempt to minimize injuries in young baseball players. We hypothesized that playing pitcher or catcher and increased innings played during the season would result in dominant shoulder magnetic resonance imaging (MRI) abnormalities.

METHODS

A prospective evaluation of Little League players aged 10 to 12 years was performed. Players recruited before the start of the season underwent bilateral preseason and dominant shoulder postseason MRI, physical examination, and questionnaires addressing their playing history and arm pain. Innings played, player position, pitch counts, and all-star team selection were recorded.

RESULTS

In total, 23 players were enrolled. The majority (19/23, 82.6%) were right-handed and 16 of 23 (69.6%) played at least 10 innings as pitcher or catcher. Sixteen were selected for the all-star team. Fourteen players (60.9%) had positive dominant shoulder MRI findings not present in their nondominant shoulder. Eight players (34.8%) had new or worsening postseason MRI findings. Thirteen players (81.3%) selected to the all-star team had abnormal MRI findings whereas only one (14.3%) player not selected as an all-star had MRI abnormalities (P=0.005). Year-round play (P=0.016), innings pitched (P=0.046), innings catcher (P=0.039), and number of pitches (P=0.033) were associated with any postseason MRI abnormality, but not for new or worsening MRI changes. Single sport athletes and players playing for multiple teams were significantly more likely to have abnormal MRI findings (P=0.043 and 0.040, respectively) when compared with multisport athletes playing on a single team.

CONCLUSIONS

MRI abnormalities involving the dominant shoulder are common in Little League baseball players and often develop or worsen during the season. Contrary to our hypothesis, MRI abnormalities were not associated with player position and pitch counts. Instead, they were most closely associated with year round play, single sports participation, and all-star team selection. The increased demands required for all-star selection comes at a price to the young athlete as the majority of players selected for this honor had abnormal MRI findings in their throwing shoulder while few non all-stars demonstrated such pathology.

LEVEL OF EVIDENCE

Level II.

Attitudes and Beliefs towards Sport Specialization, College Scholarships, and Financial Investment among High School Baseball Parents

Adolescent athletes are increasingly encouraged to specialize in a single sport year-round in an effort to receive a college scholarship. For collegiate baseball, only 11.7 scholarships are available for a 35-player team. The beliefs of the parents of baseball athletes towards sport specialization are unknown, along with whether they have an accurate understanding of college baseball scholarship availability. The parents of high school baseball athletes were recruited to complete an anonymous questionnaire that consisted of (1) parent and child demographics, (2) child baseball participation information, and (3) parent attitudes and beliefs regarding sport specialization and college baseball scholarships. One hundred and fifty-five parents participated in the questionnaire (female: 52.9%, age: 49.4 ± 5.5 years old). The parents spent a median of 3000 USD [Interquartile Range (IQR): 1500–6000] on their child’s baseball participation. Most parents believed that specialization increased their child’s chances of getting better at baseball (N = 121, 79.6%). The parents underestimated the number of college baseball scholarships available per team (median [IQR]: 5 [0–5]), but 55 parents (35.9%) believed it was likely that their child would receive a college baseball scholarship. Despite having a realistic understanding of the limited college scholarships available, the parents were optimistic that their child would receive a baseball scholarship.

Curveballs in Youth Pitchers: A Review of the Current Literature

As the number of young people playing baseball has increased, so have the number of injuries. Throwing arm shoulder and elbow injuries are most common, and lead to both short and long-term consequences. Recent efforts have been made to identify risk factors for injury with corresponding regulations created to protect youth pitchers. Unlike rules enforcing pitch counts, prohibitions against curveballs are based on minimal objective evidence.

Distance-Based Throwing Programs for Baseball Players From Little League to High School

An estimated 2.4 million children play baseball in 80 countries. The majority of these children have experienced pain with throwing. A key component to a successful rehabilitation after an upper extremity injury for a baseball player is an interval throwing program, which allows a youth athlete to increase the demands of throwing in a progressive and controlled manner. Numerous interval throwing programs are designed for baseball players of high school age and older, but few exist for the baseball player who is skeletally immature. Our interval throwing programs take into consideration various field dimensions, injury types, and position requirements for youth. Our goal is to create a guide for rehabilitation specialists and players to return to throwing as quickly and safely as possible.

Epidemiology and Impact of Prior Musculoskeletal Injury and Orthopaedic Surgery on Draft Rank, Availability, and Short-term Performance in Major League Baseball: A Summary Analysis and Matched Cohort of 1890 Predraft Players

Background:

Despite the many reports of injury rates in Major League Baseball (MLB), little is known about the epidemiology or impact of prior musculoskeletal injuries and surgical procedures among players entering the MLB draft.

Purpose:

To determine the (1) epidemiology of all musculoskeletal injuries and surgical procedures among players entering the MLB draft, (2) impact of injury or surgery on draft rank, (3) impact of injury or surgery on availability within the first 2 years of play in the MLB, and (4) impact of injury or surgery on performance.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively reviewed 1890 medical records that were completed by MLB team physicians as preparticipation physical assessment prior to the draft from 2014 to 2018. Players were divided into 3 groups: noninjured, nonoperative, and operative. Draft status, overall draft rank, missed games, batting average, and earned run average for the first 2 seasons of MLB play were obtained for all available players. Players across all 3 groups were compared with linear, logistic, and beta regression models, controlling for age, position, injury status, and draft rank. Unadjusted differences among groups were assessed with 1-way analysis of variance.

Results:

Overall, 750 position players and 1140 pitchers were included, of whom 22.8% had no reported injury history; 48.8% reported injury treated nonoperatively; and 28.5% were treated operatively. The most common predraft injuries were elbow tendinitis (n = 312), ulnar collateral ligament injury (n = 212), and shoulder labral tear (n = 76). The most common predraft treatments were physical therapy (n = 922), ulnar collateral ligament reconstruction (n = 115), and fracture fixation (n = 69). Of the 1890 players, 719 were drafted and played for at least 2 years. No difference was found among noninjured, nonoperative, and operative groups in terms of draft rank, games missed, or performance. Players with a nonoperative injury had a decreased odds ratio of being drafted (0.738; P = .017).

Conclusion:

More than half of the players entering the MLB reported a history of musculoskeletal injury requiring treatment, and the most commonly affected joints were the shoulder and elbow. Musculoskeletal history did not affect draft rank, short-term availability, or performance for MLB prospects.

A Comparison of Team Sport Volume Surveyed Between High School and Club Sport Coaches

BACKGROUND

Club sport participation is increasingly common among high school athletes. Sport participation characteristics may vary widely between the high school and club sport settings. However, there have been no large-scale comparisons of sport participation volume between high school and club teams from similar sports.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the sport participation characteristics of high school and high school-aged club teams. We hypothesized that club team athletes would participate in more months per year and hours per week and would take more overnight trips than high school athletes and that club team coaches would be less likely to track their athletes' sport volume than high school coaches.

STUDY DESIGN

Cross-sectional study.

METHODS

A total of 769 coaches (266 female; 34.6%) from 3 sports (basketball, volleyball, soccer) completed an anonymous online questionnaire regarding their team's sport volume and their knowledge, attitudes, and beliefs regarding sport specialization. Coaches were eligible to participate if they had served as the head or assistant coach of a high school sport team or high school-aged club sport team in the past 12 months.

RESULTS

Overall, 64.6% (n = 497) were coaches of a high school team, and 35.4% (n = 272) were coaches of a club team with high school-aged athletes. Club coaches' teams played more months out of the year and took more overnight trips for competitions than high school coaches' teams but participated in fewer hours per week of practices or competitions during their season. There were no differences between club and high school coaches in tracking their athletes' sport volume, with most coaches in both settings reporting that they do not track the amount of time that their athletes participate in other sports.

CONCLUSION

Significant differences in sport participation volume exist between the teams of high school and club coaches.

Increased pitch velocity and workload are common risk factors for ulnar collateral ligament injury in baseball players: a systematic review

Importance

Ulnar collateral ligament (UCL) injuries commonly occur in baseball players. Strategies for injury prevention have long been accepted without clinical data informing which risk factors lead to serious injury.

Objective

The objective of this study was to systematically review the impact of various pitching-related risk factors for UCL injury in baseball players from all levels of play.

Evidence review

The electronic databases MEDLINE, EMBASE and PubMed were systematically searched until 4 March 2018, and pertinent data were abstracted by two independent reviewers. Search terms included ‘ulnar collateral ligament’, ‘medial ulnar collateral ligament’, ‘Tommy John’, ‘risk’ and ‘association’. Inclusion criteria were English-language studies, level of evidence I–IV and studies reporting risk factors for UCL injury of the elbow in baseball players. Study quality was assessed using the methodological index for non-randomised studies (MINORS) criteria. The results are presented in a narrative summary.

Findings

Pitching practices (workload and pitch characteristics) were reported in 9/15 studies. Specifically, three of four studies (n=1810) reported increased pitch workload as a risk factor for native UCL injury (p<0.001 to 0.02). The most common pitch characteristic reported was pitch velocity with four of five studies showing increased velocity being significantly associated with native UCL injury (p<0.01 to 0.02). Biomechanical risk factors reported were increased humeral retrotorsion (two studies; n=324), poor lower extremity and trunk balance (one study; n=42) and loss of total arc of shoulder motion (two studies; n=118), all significantly associated with UCL injury (p<0.0001 to 0.05). One of three studies assessing pitch workload as a risk factor for re-rupture of UCL reconstruction found a significant association (p<0.01).

Conclusions and relevance

Pitching practices, reflected by increased pitch workload and velocity, were most commonly associated with UCL injury; however, the definition of workload (number of pitches per game, inning or season) was inconsistently reported. Biomechanical risk factors were less commonly reported and lack sufficient evidence to recommend preventative strategies. More quality data is needed to refine the current recommendations for injury prevention in baseball players.

Level of evidence

III.

Can We Reduce the Epidemic of Elbow Injuries in Youth Throwers?

As participation in youth sports continues to increase across the nation, more adolescents are participating in Little League baseball in the United States than ever before. Accompanying this increased participation is an epidemic of upper extremity injuries in young throwers. In this Viewpoint, the authors discuss the impetus behind the youth thrower elbow injury epidemic and how to best evaluate these patients. J Orthop Sports Phys Ther 2018;48(5):354-357. doi:10.2519/jospt.2018.0607.

Outcomes and Return to Sport After Ulnar Collateral Ligament Reconstruction in Adolescent Baseball Players

Background:

The number of ulnar collateral ligament (UCL) reconstructions in adolescent athletes has increased over the past 2 decades. Clinical results in this population have not been well studied.

Purpose/Hypothesis:

The purpose of this study was to evaluate the outcomes and return to sport after UCL reconstruction in a large group of adolescent baseball players. We hypothesized that excellent clinical outcomes and high rates of return to sport would be observed in this population at a minimum 2-year follow-up.

Study Design:

Case series; Level of evidence, 4.

Methods:

We reviewed 140 adolescent (aged ≤19 years) baseball players who underwent UCL reconstruction with the American Sports Medicine Institute (ASMI) technique by a single surgeon. Medical records were reviewed for patient demographics, injury characteristics, operative details, and surgical complications. Patient-reported outcomes were assessed using the Conway scale, the Andrews-Timmerman (A-T) score, the Kerlan-Jobe Orthopaedic Clinic (KJOC) score, and a 0- to 100-point subjective scale for elbow function and satisfaction. Return to sporting activity was assessed using a custom-designed questionnaire.

Results:

The mean age at the time of surgery was 18.0 years (range, 13-19 years), and the mean follow-up was 57.9 months (range, 32.4-115.4 months). Over half (60%) of patients were high school athletes. The mean duration of symptoms before surgery was 6.9 months (range, 0.5-60.0 months). Partial tears were identified in 57.9% of patients, and 41.3% of patients had preoperative ulnar nerve symptoms. Graft type included the ipsilateral palmaris in 77.1% of patients. Concomitant procedures were performed in 25% of patients. Outcomes on the Conway scale were “excellent” in 86.4% of patients. The mean A-T and KJOC scores were 97.3 ± 6.1 and 85.2 ± 14.6, respectively. Mean patient satisfaction was 94.4. Overall, 97.8% of patients reported returning to sport at a mean of 11.6 months (range, 5-24 months), and 89.9% of patients returned to sport at the same level of competition or higher. A total of 11.6% of patients went on to play professional baseball.

Conclusion:

UCL reconstruction with the ASMI technique is an effective surgical option in adolescents, with excellent outcome scores. At a minimum of 2-year follow-up, nearly 90% of patients returned to their preinjury level of sport.

Shoulder MRI Abnormalities in Asymptomatic Little League Baseball Players

Background:

Youth baseball is extremely popular in the United States, but it has been associated with shoulder pain and injury. The incidence of shoulder abnormalities in this athletic population has yet to be defined.

Purpose:

To examine abnormalities noted on magnetic resonance imaging (MRI) in the shoulders of asymptomatic Little League baseball players and to correlate these findings with the players’ throwing history and physical examinations.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 23 Little League baseball players aged 10 to 12 years were recruited. All players underwent a comprehensive physical examination and responded to a questionnaire addressing their playing history and any arm or shoulder pain. Bilateral shoulder MRIs were performed and read in a blinded manner by 2 radiologists. Responses on the questionnaire and physical examination findings were compared between participants with and without positive MRI findings through use of chi-square test and analysis of variance.

Results:

The dominant arm was 8.5 times more likely to have an abnormality on MRI compared with the nondominant arm. In all, 12 players (52%) had 17 positive MRI findings in their throwing shoulder that were not present in their nondominant shoulder. These findings included edema or widening of the proximal humeral physis (n = 5), labral tear (n = 4), partial rotator thickness tear (n = 4), acromioclavicular joint abnormality (n = 2), subacromial bursitis (n = 1), and cystic change of the greater tuberosity (n = 1). Two primary risk factors were associated with an abnormal MRI: year-round play and single-sport athletes focusing solely on baseball (P < .05). Players with no risk factors, 1 risk factor, and both risk factors had a 25%, 71%, and 100% chance, respectively, of having an abnormal MRI. A majority of players (61%) had previously experienced shoulder pain, especially pitchers throwing curveballs and sliders (P < .05), but this was not associated with an abnormal MRI.

Conclusion:

Abnormalities seen on MRI involving the shoulder are common in Little League baseball players, especially those who are single-sport athletes playing year-round.

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.