Unaccounted for Pitch Volume Among Adolescent Baseball Pitchers During a Travel Baseball Season

OBJECTIVE

The primary aim was to compare differences in live game pitch counts (LGPCs) with all pitch counts (APCs) over the course of a youth baseball season.

DESIGN

Prospective longitudinal study.

SETTING

Midwest youth travel baseball.

PARTICIPANTS

Ten male baseball players part of a youth baseball travel team.

VARIABLES

Demographic data, pitch counts (practice, game, warm-up, and bullpen), innings pitched, and recommended rest days.

MAIN OUTCOME MEASURES

Live pitch counts compared with APCs and the relationship to recommended rest days.

RESULTS

During the season, 7866 pitches were recorded among 9 pitchers. By using the LGPC method alone, 42.5% of the pitches were unaccounted for. When considering age-specific rest days suggested by Pitch Smart Guidelines (PSGs), there were 104 rest days unaccounted for by using the live game pitch method.

CONCLUSION

There is a high number of unaccounted for pitches and an underestimation of rest days per outing when using live game methods. Revisions to the PSGs that include all pitches should be considered to accurately reflect pitching volume, which may be associated with the rising rate of injuries among these athletes.

The Epidemiology of Youth Sport-Related Shoulder Injuries: A Systematic Review

Background

Youth around the globe place their shoulders at risk for injury when participating in sports. Shoulder injuries may vary in severity, produce the potential for time-loss from sport, and result in functional disability. We sought to explore sport-related shoulder injuries in youth by identifying injury rates, risk factors, injury mechanisms, and injury prevention strategies.

Methods

All relevant full-text articles were identified by searching MEDLINE, EMBASE, CINAHL, Sport Discus, and the Cochrane Controlled Trials Registry. No date restrictions were used. All full-text studies reporting original research describing sport-related shoulder injury among female and/or male youth from 5 to 18 years old were included.

Results

Of 3,889 studies screened, 97 described shoulder injury in youth sports. Shoulder injuries were identified in 24 unique sports. The median seasonal prevalence of shoulder injury was 10.9% (range 1.2-28.2%). The most common injury mechanisms identified were contacted with another player, contact with the playing environment, and falling to the ground. Risk factors for shoulder injury identified were side-to-side strength imbalances, weak external rotator muscles, and scapular dyskinesia. One study evaluated a successful training strategy to prevent shoulder injuries, but two other interventions demonstrated no effect.

Conclusions

Sport-related shoulder injuries are prevalent among youth athletes. Injury risk factors identified included modifiable intrinsic factors such as strength, range of motion, and training load. The most common injury mechanism was direct contact with either another person or an object in the playing environment. Innovative shoulder-specific strategies are needed to reduce shoulder injuries in this population. Trial Registration: PROSPERO ID: CRD42020189142.

Increased Shoulder Distraction Force and Shoulder Horizontal Abduction in Professional Baseball Pitchers With Discordant Torso Rotation Order

BACKGROUND

Inefficient energy transfer from the pelvis and trunk has been shown to increase compensation at the level of the shoulder. Kinetic chain sequencing of the core segments is underexamined in professional baseball pitchers, especially as it relates to changes in upper extremity kinetics.

PURPOSE

To evaluate elbow and shoulder kinetics in a cohort of professional pitchers differentiated by instances of discordant pelvic to upper torso sequencing during the pitch.

STUDY DESIGN

Descriptive laboratory study.

METHODS

285 professional baseball pitchers were evaluated using 3D motion capture (480 Hz). Pitchers were divided into "chronological" and "discordant" groups based on whether maximum pelvic rotation velocity occurred before (chronological) or after (discordant) maximum upper torso rotation velocity during the pitch motion. Pelvic, upper torso, and shoulder kinematic parameters, shoulder distraction force, shoulder internal rotation torque, and pitch efficiency (PE) were compared between groups.

RESULTS

Pitchers with discordant torso sequencing (n = 30; 110 pitches) had greater shoulder horizontal adduction at maximum external rotation (mean difference, 3.6°; 95% CI, -5.2° to -2.0°; t = -4.5; P < .001) and greater maximum shoulder external rotation (mean difference, 3.7°; 95% CI, 5.7° to 1.5°; t = -3.5; P < .001) than chronological pitchers (n = 255; 2974 pitches). PE did not differ between groups (P = .856), whereas ball velocity was significantly faster in the discordant group (mean difference, 0.6 m/s; 95% CI, -1.1 to -0.3 m/s; t = -3.3; P = .0012). Chronological pitchers had significantly reduced shoulder distraction force (mean difference, -4.7% body weight (BW); 95% CI, -7.9% to -1.5% BW; t = -2.9; P = .004) with no difference in shoulder internal rotation torque (P = .160). These kinematic and kinetic differences were not observed when accounting for interpitcher variability.

CONCLUSION

Between pitchers, those who had a discordant pelvic to upper torso sequence experienced significantly greater shoulder distraction forces, potentially compensating by increasing maximum shoulder external rotation and horizontal abduction. Achieving maximal pelvic rotation velocity before maximal rotation velocity may be advantageous in preventing compensation at the upper extremity and excessive throwing arm loading.

CLINICAL RELEVANCE

Identifying risk factors for increased upper extremity forces has potential implications in injury prevention. Specifically, mitigating shoulder distraction forces may be beneficial in reducing risk of injury.

Short-Term Trends in Elbow Ulnar Collateral Ligament Surgery in Collegiate Baseball Players: An Analysis of 25,587 Player-Years

Background

Trends over time in the incidence of ulnar collateral ligament (UCL) surgeries in National Collegiate Athletic Association Division I baseball players are currently unknown.

Purpose/Hypothesis

The purpose of this study was to evaluate the trends in UCL surgeries over 3 years in Division I baseball programs. We hypothesized that surgical injuries would be consistently high over the course of the study.

Study Design

Descriptive epidemiology study.

Methods

Athletic trainers from Division I baseball programs were invited to participate in an electronic survey over 3 seasons. A total of 155 baseball programs agreed to participate in 2017, 294 programs participated in 2018, and 296 programs participated in 2019. After each of the 3 collegiate baseball seasons, the athletic trainer from each program entered anonymous, detailed descriptive data and surgical information on injured players into a secured database.

Results

During the 3 years of this study, 100% of the enrolled programs successfully completed the survey (155/155 in year 1, 294/294 in year 2, and 296/296 in year 3). This registry of 745 completed surveys over 3 years represented 25,587 player-years from Division I collegiate baseball. The percentage of programs with at least 1 UCL surgery during this time was 57% in 2017, 51% in 2018, and 49% in 2019. The majority of these players were pitchers (84% overall from the 3 years). Seniors underwent a significantly lower percentage of the UCL surgeries (8% in 2017, 10% in 2018, and 13% in 2019) than did underclassmen. Surgeries were performed most often in-season and least often during the preseason. A slight majority of players undergoing surgery originated from warm-weather states, but the number of these players was never significantly higher than was the number of players from cold-weather states. Most surgeries performed each year were UCL reconstruction, but the percentage of UCL repair with ligament augmentation increased each year (10% UCL repairs in 2017, 20% in 2018, and 25% in 2019).

Conclusion

UCL injuries requiring surgery were found to be a major source of morbidity in Division I collegiate baseball, supporting our hypothesis. This study can serve as a baseline for tracking long-term trends in UCL surgeries in collegiate baseball.

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.

Prevalence and Consequences of Sport Specialization Among Little League Baseball Players

BACKGROUND

Baseball is one of the most popular boy's youth sports, and there has been a rise in the rates of certain overuse injuries among players. Specialization has been identified as a risk factor for overuse injury in high school athlete populations, but there is little understanding of the prevalence or consequences of sport specialization in Little League baseball players.

HYPOTHESIS

Sport specialization will be highly prevalent among Little League baseball players and specialization will be associated with worse throwing arm health.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 246 Little League baseball players (male; N = 241; age, 9.5 ± 1.6 years) between 7 and 12 years old completed an anonymous, online questionnaire with their parent's assistance. The questionnaire consisted of participant demographics and baseball participation information, including sport specialization status and the Youth Throwing Score (YTS), a valid and reliable patient-reported outcome measure for youth baseball players.

RESULTS

Only 29 (11.8%) players met the criteria for high specialization. Approximately one-third of all players (n = 77; 31.3%) reported participating in baseball year-round or receiving private coaching outside of their league (n = 81; 32.9%). Highly specialized athletes demonstrated worse scores on the YTS on average compared with low-specialization athletes (mean [SE]: 56.9 [1.6] vs 61.1 [1.2]; P = 0.01). Similarly, pitching in the previous year (P < 0.01) or traveling overnight regularly for showcases (P = 0.01) were associated with a worse score on the YTS.

CONCLUSION

While the prevalence of high sport specialization was low among Little League baseball players, other behaviors associated with specialization such as year-round play and the receiving of private coaching were more common. Highly specialized Little League players demonstrated worse throwing arm health compared with low-specialization players.

CLINICAL RELEVANCE

Little League players and their parents may represent a potential target audience for dissemination campaigns regarding sport specialization.

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.

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.

Non-Time-Loss and Time-Loss Softball Injuries in Secondary School Athletes: A Report From the National Athletic Treatment, Injury and Outcomes Network (NATION)

CONTEXT

Most studies of injury trends associated with softball focus on injuries requiring at least 24 hours of missed participation time (time-loss [TL] injuries), with little focus on those that do not (non-time-loss [NTL] injuries). A better understanding of injury trends associated with softball will improve athlete care.

OBJECTIVE

To describe NTL and TL injuries experienced by secondary school girls' softball players.

DESIGN

Descriptive epidemiology study.

SETTING

Secondary school athletic training clinics.

PATIENTS OR OTHER PARTICIPANTS

Secondary school girls' softball players.

MAIN OUTCOME MEASURE(S)

Aggregate data were collected from schools participating in the National Athletic Treatment, Injury, and Outcomes Network surveillance program during the 2011-2012 through 2013-2014 academic years. Frequencies and rates of injuries (NTL and TL) according to time of season, event type, body part injured, and diagnosis were analyzed.

RESULTS

In total, 1059 injuries were reported during 140 073 athlete-exposures (AEs): overall injury rate = 7.56/1000 AEs. Of these injuries, 885 (83.6%) were NTL (NTL rate = 6.32/1000 AEs) and 174 (16.4%) were TL (TL rate = 1.24/1000 AEs). Of the NTL and TL injuries, the largest numbers occurred during the regular season (NTL: n = 443 [50.1%]; TL: n = 131 [75.3%]). Injuries sustained during practices accounted for the majority of NTL and TL injuries (NTL: n = 631 [71.3%]; TL: n = 104 [59.8%]). The NTL injuries occurred most often at the shoulder (n = 134 [15.1%]) and hand/fingers (n = 109 [12.3%]) and were diagnosed as contusions (n = 316 [35.7%]), strains (n = 157 [17.7%]), and abrasions (n = 151 [17.1%]). The largest numbers of TL injuries were to the head/face (n = 71 [40.8%]) and diagnosed as concussions (n = 50 [28.7%]) and strains (n = 28 [16.1%]).

CONCLUSIONS

Secondary school softball players sustained a larger proportion of NTL injuries than TL injuries. Although NTL injuries may be less severe, they are numerous. Efforts are needed to ensure that injury-prevention programs are incorporated into the care of softball athletes to promote health and reduce injury occurrence.

Restriction in the hip internal rotation of the stride leg is associated with elbow and shoulder pain in elite young baseball players

BACKGROUND

Evidence is scarce concerning the relationship of physical dysfunction of the trunk and lower extremities with elbow and shoulder pain in young baseball players. This study aimed to examine the association of joint flexibility of the trunk and lower extremities and dynamic postural control with elbow and shoulder pain among elite young baseball players.

METHODS

We analyzed baseball players (aged 9-12 years) who participated in the National Junior Sports Clubs Baseball Festival. Range of motion in external rotation and internal rotation (IR) of the hip, as well as the finger-to-floor distance and heel-to-buttock distance, was measured. The straight-leg-raise test was also conducted. Dynamic postural control was evaluated using the Star Excursion Balance Test. Multivariable logistic regression analyses were conducted to examine the association of physical function with the elbow or shoulder pain incidence.

RESULTS

Of 210 players surveyed, 177 without elbow or shoulder pain were included in the analysis. Of the participants, 16 (9.0%) reported having elbow or shoulder pain during the tournament. Participants with the incidence of elbow or shoulder pain had a significant restriction in hip IR of the stride leg compared with those without pain (35.8° vs. 43.7°, P = .022). There were no significant associations of other joint flexibilities and the Star Excursion Balance Test with elbow or shoulder pain.

CONCLUSION

Decreased hip IR range of motion of the stride leg was significantly associated with the elbow or shoulder pain incidence. Players, coaches, and clinicians should consider the physical function of the trunk and lower extremities for the prevention of elbow and shoulder pain.

Association Between Parental Understanding of Pitch Smart Guidelines and Youth Baseball Player Injuries

Background

Injuries continue to rise among youth baseball players despite extensive research into prevention and the availability of throwing guidelines such as Pitch Smart. More research is needed to understand whether adherence to the current guidelines decreases injuries.

Purpose

To understand the degree to which parents are aware of the Pitch Smart guidelines, whether parents adhere to the guidelines, and whether adherence results in decreased injuries in youth baseball players.

Study Design

Cross-sectional study.

Methods

An anonymous, internet-based survey consisting of 44 items was distributed to parents of adolescent baseball players affiliated with various youth baseball organizations across the midwestern United States; 15 items on the survey served as assessment questions of the Pitch Smart guidelines. Absolute and percentage correct scores were calculated and compared by use of a Student t test. A chi-square analysis was used to compare discrete data. A binary logistic regression analysis was conducted to determine whether showcase participation predicted player injury.

Results

A total of 853 parents completed the survey. The mean ± SD age of the players on whom parents reported was 11.37 ± 3.5 years (range, 6-20 years). Among the cohort, 422 players regularly pitched. Regarding Pitch Smart guidelines, the percentage of correct answers by parents was 55.44% ± 0.3% for a player with a reported injury history and 62.14% ± 0.2% for a player without an injury history (P = .012). The number of correct answers was 8.03 ± 4.0 for the group with an injury history and 9.17 ± 3.2 for the group with no history of injury (P = .004). Binary logistic regression analysis, which controlled for age, indicated that showcase participation (P = .001, β = 1.043 ± 0.026, R² = 0.178) was a significant predictor of player injury.

Conclusion

Pitchers are at an increased risk of injury compared with nonpitchers. Parents who are knowledgeable about the Pitch Smart throwing guidelines and actively follow them are significantly less likely to have a child with an injury. Excessive showcase participation is predictive of player injury when the analysis controls for age.

Risk Factors for Elbow and Shoulder Injuries in Adolescent Baseball Players: A Systematic Review

BACKGROUND

The incidence of shoulder and elbow injuries among adolescent baseball players is on the rise. These injuries may lead to surgery or retirement at a young age.

PURPOSE

To identify independent risk factors for elbow and shoulder injuries in adolescent baseball players. A secondary aim was to determine whether the literature supports the Major League Baseball and USA Baseball Pitch Smart guidelines.

STUDY DESIGN

Systematic review.

METHODS

A systematic review was performed in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines utilizing MEDLINE, SPORTDiscus, and Web of Science. Because of study heterogeneity, a quantitative synthesis was not performed. A qualitative review was performed on 19 independent risk factors for elbow and shoulder injuries in adolescent baseball players. Level of evidence was assigned per the Oxford Centre for Evidence-Based Medicine Working Group, and risk of bias was graded per the Newcastle-Ottawa Scale.

RESULTS

Twenty-two articles met criteria for inclusion. Of the 19 independent variables that were analyzed, age, height, playing for multiple teams, pitch velocity, and arm fatigue were found to be independent risk factors for throwing arm injuries. Pitches per game appears to be a risk factor for shoulder injuries. Seven independent variables (innings pitched per game, showcase participation, games per year, training days per week, pitch type, shoulder external rotation, and shoulder total range of motion) do not appear to be significant risk factors. The data were inconclusive for the remaining 6 variables (weight, months of pitching per year, innings or pitches per year, catching, shoulder horizontal adduction, and glenohumeral internal rotation deficit).

CONCLUSION

The results from this study demonstrate that age, height, playing for multiple teams, pitch velocity, and arm fatigue are clear risk factors for throwing arm injuries in adolescent baseball players. Pitches per game appears to be a risk factor for shoulder injuries. Other variables are either inconclusive or do not appear to be specific risk factors for injuries.

Elbow Ulnar Collateral Ligament Reconstruction Using the Novel Docking Plus Technique in 324 Athletes

BACKGROUND

This retrospective case series examined 324 athletes who received elbow ulnar collateral ligament (UCL) reconstruction by a single surgeon in a private practice over a 9-year period. The novel Docking Plus technique for elbow UCL reconstruction in 324 athletes provided good or excellent Conway score results in 88% of patients. The preponderance of previous studies examining UCL reconstruction outcomes were performed by surgeons at one of only three institutions (Andrews Institute, Hospital for Special Surgery, Kerlan Jobe Orthopedic Clinic).

METHODS

Patients undergoing UCL reconstruction from November 2005 to December 2014 were identified and contacted with a mailed survey and phone call. These patients were given a subjective 19 question survey assessing their outcomes from surgery.

RESULTS

The participants who responded to our survey were 90% male and 77% baseball players, 73% of which were pitchers. Of the baseball players who responded, 51.9% were in high school at the time of their surgery, 37% college, 6.5% minor leagues, and 2.2% in Major League Baseball. After surgery, 36% of survey responders returned to a higher level of competition than previously. For example, a high school athlete who had UCL reconstruction and went on to pitch in college. Further, 45% returned to the same level, and 7% returned to a lower level. Subjective "satisfaction," was reported in 92% of responders and 97.2% reported that, "having surgery was a good idea." Symptom onset in the responding athletes was 58.9% sudden, and 41.1% gradual. Overall, 90.9% of respondents returned to play in less than 1.5 years while 6.3% never were able to return. Re-tear occurred in 2.5% of patients, while 8.8% had subjective nerve dysfunction for at least 3 months following surgery.

CONCLUSION

The Docking Plus technique can produce excellent subjective and objective results in athletes. Further study is warranted to see the effects of this procedure in other settings and determine which method of reconstruction or repair is superior.

Playing video games for more than 3 hours a day is associated with shoulder and elbow pain in elite young male baseball players

BACKGROUND

The effect of lifestyle factors on elbow or shoulder pain in young baseball players remains unclear. This study examined the association of game playing and television viewing with elbow or shoulder pain among elite young baseball players.

METHODS

Study participants were young baseball players (age, 9-12 years) who participated in the National Junior Sports Clubs Baseball Festival in 2017. The national tournament invited 16 teams (totaling 210 players) selected based on the results of the regional qualifying tournaments. Self-reported questionnaires were mailed to all players before the tournament. Multiple logistic regression analyses were used to assess the association of video game playing and television viewing behavior with elbow or shoulder pain.

RESULTS

Among the 210 players polled, 200 male players were included in the analysis. The prevalence of elbow or shoulder pain was 30.0%. Playing video games for ≥3 hours/day was significantly associated with elbow or shoulder pain vs. spending <1 hour/day playing video games (odds ratio, 5.59; 95% confidence interval, 1.44-21.64; P = .013). The amount of time spent watching television was not significantly associated with the prevalence of elbow or shoulder pain.

CONCLUSIONS

Playing video games for ≥3 hours/day was associated with elbow or shoulder pain among elite young male baseball players. These findings highlight the effect of lifestyle on elbow and shoulder pain and should be taken into consideration by players, coaches, parents, and clinicians for the prevention of elbow and shoulder pain.

Reliability and Validity of a 1-Person Technique to Measure Humeral Torsion Using Ultrasound

CONTEXT

  Knowledge of the bilateral difference in humeral torsion (HT) enables clinicians to implement appropriate interventions for soft tissue restrictions of the shoulder to restore rotational motion and reduce injury risk. Whereas the current ultrasound method for measuring HT requires 2 assessors, a more efficient 1-person technique (1PT) may be of value.

OBJECTIVE

  To determine if a 1PT is a reliable and valid alternative to the established 2-person technique (2PT) for indirectly measuring HT using ultrasound.

DESIGN

  Descriptive laboratory study.

SETTING

  Biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS

  A convenience sample of 16 volunteers (7 men, 9 women; age = 26.9 ± 6.8 years, height = 172.2 ± 10.7 cm, mass = 80.0 ± 13.3 kg).

MAIN OUTCOME MEASURE(S)

  We collected the HT data using both the 1PT and 2PT from a total of 30 upper extremities (16 left, 14 right). Within-session intrarater reliability (intraclass correlation coefficient; ICC [3,1]) and standard error of measurement (SEM) were assessed for both techniques. Simple linear regression and Bland-Altman analysis were used to examine the validity of the 1PT when compared with the established 2PT.

RESULTS

  The 1PT (ICC [3,1] = 0.992, SEM = 0.8°) and 2PT (ICC [3,1] = 0.979, SEM = 1.1°) demonstrated excellent within-session intrarater reliability. A strong linear relationship was demonstrated between the HT measurements collected with both techniques ( r = 0.963, r² = 0.928, F_1,28 = 361.753, P < .001). A bias of -1.2° ± 2.6° was revealed, and the 95% limits of agreement indicated the 2 techniques can be expected to vary from -6.3° to 3.8°.

CONCLUSIONS

  The 1PT for measuring HT using ultrasound was a reliable and valid alternative to the 2PT. By reducing the number of testers involved, the 1PT may provide clinicians with a more efficient and practical means of obtaining these valuable clinical data. ^a.

Incidence of Elbow Ulnar Collateral Ligament Surgery in Collegiate Baseball Players

Background:

Recent reports have highlighted the progressive increase in the incidence of ulnar collateral ligament (UCL) injuries to the elbow in baseball players of all levels. However, knowledge of the incidence and other epidemiological factors regarding UCL injuries, specifically in college baseball players, is currently lacking.

Purpose:

To evaluate, over a period of 1 year, the incidence of UCL injuries requiring surgery in National Collegiate Athletic Association (NCAA) Division I baseball programs.

Study Design:

Descriptive epidemiology study.

Methods:

A total of 155 Division I collegiate baseball programs agreed to participate in the study. Demographics (position, year, background [location of high school]) for all players on these rosters were obtained from public websites. At the conclusion of the 2017 collegiate baseball season, the athletic trainer for each program entered anonymous, detailed information on injured players through an electronic survey into a secured database.

Results:

All 155 teams enrolled in the study completed the electronic survey. Of the 5295 collegiate baseball players on these rosters, 134 underwent surgery for an injured UCL (2.5% of all eligible athletes), resulting in a team surgery rate of 0.86 per program for 1 year. These 134 players came from 88 teams, thus 56.8% of the study teams underwent at least 1 surgery during the year. The surgery rate was 2.5 per 100 player-seasons for all players and was significantly higher among pitchers (4.4/100 player-seasons) than nonpitchers (0.7/100 player-seasons). The surgery rate was also significantly higher in underclassmen (3.1/100 player-seasons among freshmen and sophomores) than upperclassmen (1.9/100 player-seasons among juniors and seniors) (incidence rate ratio, 1.7; 95% CI, 1.1-2.4). Players from traditionally warm-weather states did not undergo UCL surgery at a significantly different rate from players from traditionally cold-weather states (2.7/100 player-seasons vs 2.1/100 player-seasons, respectively). Nearly half of surgeries (48.5%) were performed during the baseball season.

Conclusion:

The incidence of UCL surgeries in NCAA Division I collegiate baseball players represents substantial morbidity to this young athletic population. Risk factors for injuries requiring surgery include being a pitcher and an underclassman. Awareness of these factors should be considered in injury prevention programs. Furthermore, this initial study can serve as a foundation for tracking these surgical injuries in future years and then identifying trends over time.

Role of Rotational Kinematics in Minimizing Elbow Varus Torques for Professional Versus High School Pitchers

Background:

Elbow injury rates among baseball pitchers are rapidly rising. However, this increase has been most dramatic among high school (HS) pitchers.

Purpose:

To examine pitch velocity and the kinetic and kinematic characteristics of HS versus professional (PRO) pitchers to identify potential differences that may play a role in the increased risk of ulnar collateral ligament injury in youth pitchers.

Study Design:

Controlled laboratory study.

Methods:

A total of 37 HS (mean ± SD: age, 16 ± 1 years) and 40 PRO (age, 21 ± 2 years) baseball pitchers completed maximal-effort baseball pitches during a single testing session, from which pitch velocity (PV), absolute and normalized elbow varus torque (EVT_A and EVT_N, respectively) during arm cocking and at maximum shoulder external rotation (MER), and 8 other elbow and shoulder torques or forces and rotational kinematics of the pelvis and trunk were analyzed, recorded, and compared.

Results:

PV was greater in PRO than HS athletes; EVT_A was greater in PRO than HS athletes during arm cocking and at MER; but EVT_N was similar during arm cocking and greater in HS than PRO athletes at MER. In PRO athletes, PV was not related to EVT_A during arm cocking or MER (r = 0.01-0.05). Furthermore, in PRO athletes, EVT_A during arm cocking and at MER were inversely related to upper trunk rotation at hand separation and foot contact and to pelvis rotation at elbow extension (r = –0.30 to –0.33). In contrast, in HS athletes, PV was strongly related to EVT_A during arm cocking and MER (r = 0.76-0.77). Furthermore, in HS athletes, PV and EVT_A during arm cocking and at MER were moderately or strongly related to the other elbow and shoulder torques and forces (r = 0.424-0.991), and EVT_A was not related to upper trunk rotation or pelvis rotation throughout the throwing motion (r = –0.16 to 0.15).

Conclusion:

The kinetic and rotational kinematic differences observed between PRO and HS pitchers in this study may help explain the greater performance of PRO pitchers while allowing them to minimize EVT during pitching. HS pitchers, however, do not appear to be as capable of utilizing the forces generated by rotation of their trunk and pelvis to aid in pitching, and those who throw the hardest generate the greatest forces at the shoulder and elbow. As a result, they experience higher EVTs relative to their body size, which may place them at an increased risk of injury.

Clinical Relevance:

HS pitchers throw harder primarily by generating larger forces in the arm and shoulder. Thus, owing to the relative physical immaturity of HS versus PRO pitchers, these factors may place them at an increased risk of injury. Coaches may first wish to focus on improving the rotational kinematics of HS pitchers rather than first focusing on achieving greater pitch velocities.

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.

Pitch Volume and Glenohumeral and Hip Motion and Strength in Youth Baseball Pitchers

CONTEXT

  Increased pitch volume and altered glenohumeral (GH) and hip range of motion (ROM) and strength contribute to injury risk in baseball pitchers. Although these factors affect one another, whether they are related is unknown.

OBJECTIVE

  To examine relationships among cumulative and seasonal pitch volume, ROM, and strength of the GH and hip joints in youth baseball pitchers.

DESIGN

  Cross-sectional study.

SETTING

  Baseball practice facilities.

PATIENTS OR OTHER PARTICIPANTS

  A total of 28 healthy baseball pitchers (age = 13.9 ± 2.9 years).

MAIN OUTCOME MEASURE(S)

  A demographic and pitching questionnaire was used to quantify pitch volume. Glenohumeral internal-rotation (IR) and external-rotation (ER) ROM and strength of the throwing arm; total arc of motion (IR + ER ROM); and bilateral hip IR, ER, and total arc of motion ROM and strength in IR, ER, and abduction were measured. A goniometer was used to assess ROM; a handheld dynamometer, to assess strength. Frequency analyses and bivariate correlations (age covariate) described data and identified relationships.

RESULTS

  Correlations between years of competitive play and increased strength in lead-leg hip IR ( r = 0.52, P = .02) and abduction ( r = 0.48, P = .04) and stance-leg hip IR ( r = 0.45, P = .05) were fair to good. The number of months played in the last year had a fair correlation with decreased GH IR strength ( r = -0.39, P = .04) and increased stance-leg hip IR strength ( r = 0.44, P = .05). Limited pitch time had a fair correlation with increased GH ER ROM ( r = 0.40, P = .04) and an excellent correlation with increased lead-leg hip IR ROM ( r = 0.79, P < .001). Increased innings pitched per game had a fair to good correlation with decreased GH IR strength ( r = -0.41, P = .04) and stance-leg hip ER ROM ( r = -0.53, P = .03). More pitches per game had a fair to good correlation with increased GH ER ROM ( r = 0.44, P = .05) and decreased stance-leg hip ER ROM ( r = -0.62, P = .008).

CONCLUSIONS

  The significant relationships identified in this study suggest the need to further examine youth and adolescent cumulative and seasonal pitch guidelines.

Trunk Muscle Function Deficit in Youth Baseball Pitchers With Excessive Contralateral Trunk Tilt During Pitching

OBJECTIVE

Pitching technique is one of many factors that affect injury risk. Exhibiting excessive contralateral trunk tilt (CLT) during pitching has been linked to higher ball speed but also to increased joint loading. Deficit in trunk muscle strength has been suggested as an underlying cause of this movement pattern. The purpose of the study was to compare trunk muscle strength between youth baseball pitchers with varying degree of CLT during pitching.

DESIGN

Cross-sectional study.

SETTING

Baseball practice fields.

PARTICIPANTS

Twenty-eight youth baseball pitchers.

INDEPENDENT VARIABLES

Pitching technique was captured using a video camera. Based on the 2-dimensional trunk contralateral flexion angle, pitchers were categorized into low (<15 degrees), moderate (15-30 degrees), or high (>30 degrees) CLT groups.

MAIN OUTCOME MEASURES

Maximum isometric strength tests for trunk flexion, extension, and bilateral rotation, measured using a dynamometer.

RESULTS

The pitchers with high CLT (n = 10) had longer pitching experience (P = 0.014), produced higher ball speed (P = 0.003) compared with the pitchers with moderate (n = 10) and low (n = 8) CLT, but demonstrated greater asymmetry in trunk rotation strength (relative weakness in rotation strength toward dominant side) compared with the pitchers with low CLT (P = 0.015).

CONCLUSIONS

Excessive CLT may be a strategy that young pitchers learn to achieve higher ball velocity but also may be associated with imbalance between the oblique muscles on dominant and nondominant side, which may be acquired from repetitive pitching. Strengthening and emphasizing the use of dominant side oblique muscles may keep pitchers from leaning excessively during pitching and thus decrease joint loading.

Preseason screening of shoulder range of motion and humeral retrotorsion does not predict injury in high school baseball players

BACKGROUND

Shoulder and elbow injuries are commonplace in high school baseball. Although altered shoulder range of motion (ROM) and humeral retrotorsion angles have been associated with injuries, the efficacy of preseason screening of these characteristics remains controversial.

METHODS

We conducted preseason screenings for shoulder internal and external rotation ROM and humeral retrotorsion on 832 high school baseball players and tracked their exposure and incidence on throwing-related shoulder and elbow injuries during a subsequent season. Poisson regression with robust error variance was used to determine whether preseason screening could identify injury risk in baseball players and whether the injury risk was higher for pitchers compared with players who do not pitch.

RESULTS

Shoulder rotation ROM or humeral retrotorsion at preseason did not predict the risk of throwing-related upper extremity injury (P = .15-.89). Injury risk was 3.84 higher for baseball players who pitched compared with those who did not (95% confidence interval, 1.72-8.56; P = .001).

DISCUSSION

Preseason measures of shoulder ROM and humeral retrotorsion may not be effective in identifying players who are at increased injury risk. Because shoulder ROM is a measure that fluctuates under a variety of influences, future study should investigate whether taking multiple measurements during a season can identify at-risk players. The usefulness of preseason screening may also depend on rigor of participation in sports. Future studies should investigate how preseason shoulder characteristics and participation factors (ie, pitch count and frequency, competitive level, pitching in multiple leagues) interact to predict injury risk in baseball players.

Biomechanical modeling as a practical tool for predicting injury risk related to repetitive muscle lengthening during learning and training of human complex motor skills

Previous studies have shown that muscle repetitive stress injuries (RSIs) are often related to sport trainings among young participants. As such, understanding the mechanism of RSIs is essential for injury prevention. One potential means would be to identify muscles in risk by applying biomechanical modeling. By capturing 3D movements of four typical youth sports and building the biomechanical models, the current study has identified several risk factors related to the development of RSIs. The causal factors for RSIs are the muscle over-lengthening, the impact-like (speedy increase) eccentric tension in muscles, imbalance between agonists and antagonists, muscle loading frequency and muscle strength. In general, a large range of motion of joints would lead to over-lengthening of certain small muscles; Limb’s acceleration during power generation could cause imbalance between agonists and antagonists; a quick deceleration of limbs during follow-throughs would induce an impact-like eccentric tension to muscles; and even at low speed, frequent muscle over-lengthening would cause a micro-trauma accumulation which could result in RSIs in long term. Based on the results, the following measures can be applied to reduce the risk of RSIs during learning/training in youth participants: (1) stretching training of muscles at risk in order to increase lengthening ability; (2) dynamic warming-up for minimizing possible imbalance between agonists and antagonists; (3) limiting practice times of the frequency and duration of movements requiring strength and/or large range of motion to reducing micro-trauma accumulation; and (4) allowing enough repair time for recovery from micro-traumas induced by training (individual training time). Collectively, the results show that biomechanical modeling is a practical tool for predicting injury risk and provides an effective way to establish an optimization strategy to counteract the factors leading to muscle repetitive stress injuries during motor skill learning and training.

Risk Stratification for Ulnar Collateral Ligament Injury in Major League Baseball Players: A Retrospective Study From 2007 to 2014

BACKGROUND

Ulnar collateral ligament (UCL) injury has become increasingly common in Major League Baseball (MLB) players in recent years.

HYPOTHESIS

There is a significant difference in preinjury fastball velocity between MLB pitchers with tears and matched controls without UCL injury. Pitchers with injuries are throwing harder and getting injured earlier in their MLB careers.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From 2007 to 2014, a total of 170 documented UCL injuries (156 pitchers, 14 position players) occurred in MLB. Inclusion criteria for this study consisted of any player who tore his UCL in MLB during this time frame. There were 130 regular-season tears (April-September). From this group, 118 players who pitched more than 100 innings prior to tear were matched to subjects with no tear and were compared using a logistic regression analysis. A subgroup of "early tear" players who threw less than 100 career innings (n = 37) was also identified and compared with the larger tear group using a logistic regression analysis.

RESULTS

Of the 130 tears that occurred during the regular season, a significantly larger number (62%) occurred in the first 3 months (P = .011). The rate of UCL tears per MLB player (P = .001) was statistically significant. In the group of 118 matched tears, the mean fastball velocity was greater in the tear group (91.7 mph) compared with the control group (91.0 mph; P = .014). Furthermore, relief pitchers made up a greater percentage of the early tear group (<100 innings) compared with the later tear group (P = .011). Sixteen of the 170 UCL tears (9.4%) were recurrent tears, with 5 of 16 experiencing both tear and retear within the past 4 years.

CONCLUSION

There is a statistically significant difference in the mean fastball velocity of pitchers who injure their UCL. Small increases in pitcher fastball velocity are a main contribution to the increased rate of tear in MLB. In addition, there has been an increased incidence of injury in the first 3 months of the season. Finally, early tears are more likely to occur in relief pitchers than starters.

Does Geographic Location Matter on the Prevalence of Ulnar Collateral Ligament Reconstruction in Collegiate Baseball Pitchers?

Background:

There has been a significant amount of research in the prevention of throwing injuries. However, one area of research that is lacking is geographic location of play. Warm climates may permit year-round play and increased exposure to throwing arm injury risk.

Hypotheses:

(1) Pitchers from southern institutions would have greater rates of ulnar collateral ligament reconstruction (UCL-R) compared with pitchers from northern institutions. (2) Pitchers originating from high school teams in warm weather states would have a greater risk of undergoing UCL-R while in college.

Study Design:

Descriptive epidemiological study.

Methods:

This study was completed by reviewing publicly obtained records of male collegiate baseball players during the 2008 through 2014 seasons. Data were accessed through online search engines, online baseball media guides, and school websites.

Results:

A total of 5315 player-years and 2575 pitcher-years were identified. Fifty-eight UCL-R cases were found in collegiate pitchers, 40 of which occurred in the Southeastern Conference (SEC) and 18 in the Big Ten. More injuries (36/58) occurred in pitchers who participated in high school baseball in southern states as compared with northern states (22/58), regardless of location of collegiate participation (χ² = 28.8, P < .05). The injury rate for pitchers who participated in high school baseball in southern states was 25.3 per 1000 player-years versus 19.1 per 1000 player-years in northern states, with a risk ratio of 1.32 (χ² = 0.89, P = .35). The injury rate for the SEC versus Big Ten pitchers was 13.3 per 1000 player-years versus 7.8 per 1000 player-years, with a risk ratio of 1.71 (χ² = 1.45, P = .23).

Conclusion:

There is a greater likelihood of undergoing UCL-R in the SEC compared with the Big Ten. There is also an increased risk for UCL-R for pitchers who played high school baseball in southern states versus northern states, irrespective of collegiate play location.

Clinical Relevance:

Pitchers originating from high schools in a warm weather climate may be more likely to undergo UCL-R.

Improper trunk rotation sequence is associated with increased maximal shoulder external rotation angle and shoulder joint force in high school baseball pitchers

BACKGROUND

In a properly coordinated throwing motion, peak pelvic rotation velocity is reached before peak upper torso rotation velocity, so that angular momentum can be transferred effectively from the proximal (pelvis) to distal (upper torso) segment. However, the effects of trunk rotation sequence on pitching biomechanics and performance have not been investigated.

PURPOSE

The aim of this study was to investigate the effects of trunk rotation sequence on ball speed and on upper extremity biomechanics that are linked to injuries in high school baseball pitchers. The hypothesis was that pitchers with improper trunk rotation sequence would demonstrate lower ball velocity and greater stress to the joint.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Three-dimensional pitching kinematics data were captured from 72 high school pitchers. Subjects were considered to have proper or improper trunk rotation sequences when the peak pelvic rotation velocity was reached either before or after the peak upper torso rotation velocity beyond the margin of error (±3.7% of the time from stride-foot contact to ball release). Maximal shoulder external rotation angle, elbow extension angle at ball release, peak shoulder proximal force, shoulder internal rotation moment, and elbow varus moment were compared between groups using independent t tests (α < 0.05).

RESULTS

Pitchers with improper trunk rotation sequences (n = 33) demonstrated greater maximal shoulder external rotation angle (mean difference, 7.2° ± 2.9°, P = .016) and greater shoulder proximal force (mean difference, 9.2% ± 3.9% body weight, P = .021) compared with those with proper trunk rotation sequences (n = 22). No other variables differed significantly different between groups.

CONCLUSION

High school baseball pitchers who demonstrated improper trunk rotation sequences demonstrated greater maximal shoulder external rotation angle and shoulder proximal force compared with pitchers with proper trunk rotation sequences.

CLINICAL RELEVANCE

Improper sequencing of the trunk and torso alter upper extremity joint loading in ways that may influence injury risk. As such, exercises that reinforce the use of a proper trunk rotation sequence during the pitching motion may reduce the stress placed on the structures around the shoulder joint and lead to the prevention of injuries.

Risk-Prone Pitching Activities and Injuries in Youth Baseball: Findings From a National Sample

BACKGROUND

There are relatively few published epidemiological studies that have correlated pitching-related risk factors with increased pitching-related arm problems as well as injuries.

HYPOTHESIS

High pitching volume and limited recovery will lead to arm fatigue, thus placing young pitchers at a greater risk for elbow and shoulder problems and, subsequently, an increased risk for arm injuries.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A national survey was conducted among 754 youth pitchers (ages 9 to 18 years) who had pitched in organized baseball leagues during the 12 months before the survey. Self-reported risk-prone pitching activities were identified and compared with recommendations by the American Sports Medicine Institute. Relationships between self-reported pitching activities, shoulder and elbow problems, and injuries were assessed using multivariable logistic regression.

RESULTS

Of the 754 participating pitchers, 43.4% pitched on consecutive days, 30.7% pitched on multiple teams with overlapping seasons, and 19.0% pitched multiple games a day during the 12 months before the study. Pitchers who engaged in these activities had increased risk of pitching-related arm pain (odds ratio [OR] = 2.53, 95% confidence interval [CI] = 1.14-5.60; OR = 1.85, 95% CI = 1.02-3.38; OR = 1.89, 95% CI = 1.03-3.49, respectively). Nearly 70% of the sample reported throwing curveballs, which was associated with 1.66 (95% CI = 1.09-2.53) greater odds of experiencing arm pain while throwing. Pitching-related arm tiredness and arm pain were associated with increased risk of pitching-related injuries. Specifically, those who often pitched with arm tiredness and arm pain had 7.88 (95% CI = 3.88-15.99) and 7.50 (95% CI = 3.47-16.21) greater odds of pitching-related injury, respectively. However, pitching on a travel baseball club, playing baseball exclusively, or playing catcher were not associated with arm problems.

CONCLUSION

The results of this study, along with those of others, reinforce the importance of avoiding risk-prone pitching activities to prevent pitching-related injuries among youth pitchers.

Prevention of elbow injuries in youth baseball pitchers

CONTEXT

Although baseball is a relatively safe sport, numerous reports suggest a rapid rise in elbow injury rate among youth baseball pitchers.

EVIDENCE ACQUISITION

PUBMED WAS SEARCHED FOR EPIDEMIOLOGIC, BIOMECHANICAL, AND CLINICAL STUDIES OF ELBOW INJURIES IN BASEBALL (KEYWORDS: "youth OR adolescent" AND baseball AND pitching AND "ulnar collateral ligament OR elbow"; published January 2000 - April 2012). Studies with relevance to youth baseball pitchers were reviewed. Relevant references from these articles were also retrieved and reviewed. Original data, insight, and recommendations were added.

RESULTS

The majority of baseball elbow injuries are noncontact injuries to the dominant arm resulting from repetitive pitching. Five percent of youth pitchers suffer a serious elbow or shoulder injury (requiring surgery or retirement from baseball) within 10 years. The risk factor with the strongest correlation to injury is amount of pitching. Specifically, increased pitches per game, innings pitched per season, and months pitched per year are all associated with increased risk of elbow injury. Pitching while fatigued and pitching for concurrent teams are also associated with increased risk. Pitchers who also play catcher have an increased injury risk, perhaps due to the quantity of throws playing catcher adds to the athlete's arm. Another risk factor is poor pitching biomechanics. Improper biomechanics may increase the torque and force produced about the elbow during each pitch. Although throwing breaking pitches at a young age has been suggested as a risk factor, existing clinical, epidemiologic, and biomechanical data do not support this claim.

CONCLUSIONS

Some elbow injuries to youth baseball pitchers can be prevented with safety rules, recommendations, education, and common sense. Scientific and medical organizations have published safety rules and recommendations, with emphasis on prevention of overuse and pitching while fatigued. STRENGTH-OF-RECOMMENDATION TAXONOMY (SORT): A.