Risk factors of throwing elbow injuries during pitching Analyzed by simulation using human musculoskeletal model in youth baseball pitcher

Objectives: With the incidence of Little League elbow increasing, pitch limit recommendations for preventing throwing injuries have been developed in the United States and Japan. In 1995, the Japanese Society of Clinical Sports Medicine announced limits of 50 pitches per day and 200 pitches per week to prevent throwing injuries in younger than 12 years old. However the relationship between pitch limit recommendation and elbow injuries among pitchers has not been adequately studied. The aim of our study was to evaluate the association between pitch counts and elbow injuries in youth pitchers. Methods: A total of 149 pitchers without prior elbow pain were observed prospectively for 1 season to study injury incidence in relation to specific risk factors. Average age was 10.1 years (range, 7-11 years). One year later, all pitchers were examined by questionnaire. Subjects were asked whether they had experienced any episodes of elbow pain during the season. The questionnaire was also used to gather data on pitch counts per day and per week, age, number of training days per week, and number of games per year. We investigated the following risk factors for elbow injury: pitch counts, age, position, number of training days per week, and number of games per year. Data were analyzed by multivariate logistic regression models and presented as odds ratio (OR) and profile likelihood 95% confidence interval (CI) values. The likelihood-ratio test was also performed. A two-tailed P value of less than .05 was considered significant. All analysis was done in the SAS software package (version 8.2). Results: Of the 149 subjects, 66 (44.3%) reported episodes of pain in the throwing elbow during the season. 1. Analysis for pitch count per day Univariate analysis showed that elbow pain was significantly associated with more than 50 pitches per day. Multivariate analysis showed that more than 50 pitches per day (OR, 2.44; 95% CI, 1.22-4.94), and more than 70 games per year (OR, 2.47; 95% CI, 1.24-5.02) were risk factors significantly associated with elbow pain. Age and number of training days per week were not significantly associated with elbow pain. 1. Analysis for pitch count per week Univariate analysis showed that elbow pain was significantly associated with more than 200 pitches per week. Multivariate analysis showed that more than 200 pitches per week (OR, 2.04; 95% CI, 1.03-4.10), and more than 70 games per year (OR, 2.41; 95% CI, 1.22-4.87) were risk factors significantly associated with elbow pain. Age was not significantly associated with elbow pain. Conclusion: A total of 44.3% of youth baseball pitchers had elbow pain during the season. Multivariable logistic regression revealed that elbow pain was associated with more than 50 pitches per day, more than 200 pitches per week, and more than 70 games per year. Previous studies have revealed the risk factor with the strongest association to injury is pitcher. Our data suggest that compliance with pitch limit recommendations including limits of 50 pitches per day and 200 pitches per week may be protective against elbow injuries. Those who played more than 70 games per year had a notably increased risk of injury. With increasing demand on youth pitchers to play more, there is less time for repair of bony and soft tissues in the elbow. In conclusion, among youth pitchers, limits of 50 pitches per day, 200 pitches per week, and limits of 70 games per year may protect elbow injuries.

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

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120986791 ◽

2021 ◽

Vol 9 (4) ◽

pp. 232596712098679

Author(s):

Hitoshi Shitara ◽

Tsuyoshi Tajika ◽

Takuro Kuboi ◽

Tsuyoshi Ichinose ◽

Tsuyoshi Sasaki ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Cohort Study ◽

External Rotation ◽

Medial Epicondyle ◽

Baseball Players ◽

Elbow Pain ◽

Elbow Injury ◽

Youth Baseball ◽

Elbow Injuries

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.

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Incidence and Risk Factors for the Development of Radiographic Arthrosis After Traumatic Elbow Injuries

The Journal Of Hand Surgery ◽

10.1016/j.jhsa.2010.08.010 ◽

2010 ◽

Vol 35 (12) ◽

pp. 1976-1980 ◽

Cited By ~ 28

Author(s):

Thierry G. Guitton ◽

David Zurakowski ◽

Niek C. van Dijk ◽

David Ring

Keyword(s):

Risk Factors ◽

Elbow Injuries

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High elasticity of the flexor carpi ulnaris and pronator teres muscles is associated with medial elbow injuries in youth baseball players

The Physician and Sportsmedicine ◽

10.1080/00913847.2021.1954861 ◽

2021 ◽

Author(s):

Akira Saito ◽

Kyoji Okada ◽

Kazuyuki Shibata ◽

Hiromichi Sato ◽

Tetsuaki Kamada

Keyword(s):

Baseball Players ◽

Pronator Teres ◽

Flexor Carpi Ulnaris ◽

Youth Baseball ◽

High Elasticity ◽

Elbow Injuries

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The Influence of Pitch Velocity on Medial Elbow Pain and Medial Epicondyle Abnormality Among Youth Baseball Players

The American Journal of Sports Medicine ◽

10.1177/0363546520914911 ◽

2020 ◽

Vol 48 (7) ◽

pp. 1601-1607 ◽

Cited By ~ 1

Author(s):

Daisuke Kurokawa ◽

Takayuki Muraki ◽

Hiroaki Ishikawa ◽

Kiyotsugu Shinagawa ◽

Hideaki Nagamoto ◽

...

Keyword(s):

Medial Epicondyle ◽

Level Of Evidence ◽

Baseball Players ◽

Elbow Pain ◽

The Past ◽

Youth Baseball ◽

Elbow Injuries ◽

Internal Rotation Angle ◽

Straight Leg Raise ◽

The Relationship

Background: Pitch velocity is associated with elbow injuries among skillful baseball players. However, the relationship between pitch velocity and throwing elbow injuries among youth players has not yet been clarified. Purpose: To investigate the influence of pitch velocity on medial elbow pain and medial epicondyle abnormality among youth baseball players. Study Design: Cohort study; Level of evidence, 3. Methods: The participants consisted of 256 elementary school players (mean age, 11 ± 1 years; range, 9-12 years). The medial aspect of the elbow was evaluated using ultrasound imaging. A questionnaire was used to investigate past or present pain in the elbow, background of the players (age, height, body mass index, and years of baseball experience), and playing environment (number of days of practice in a week, experience as a pitcher, and cryotherapy of the shoulder and elbow after practice). Positioning of the scapula, range of motion in shoulder internal/external rotations and hip internal rotation, angle of the straight-leg raise, and heel-to-buttock distance were measured. The pitch velocity was recorded using a pitch velocity radar gun. The relationship between these variables and the presence of medial epicondyle abnormality, as well as past or present elbow pain, were statistically analyzed. Results: A medial epicondyle abnormality was observed in 130 players (51%), elbow pain in the past in 65 players (25%), and elbow pain during the examination in 14 players (5%). Sixty-nine players (27%) experienced elbow pain either in the past or during examination. Abnormality of the medial epicondyle had a relationship with the pitch velocity (odds ratio [OR], 1.1 for increase of 1 km/h; 95% CI, 1.1-1.2; P < .0001) and the number of practice days in a week (OR, 1.8 for increase of the practice days; 95% CI, 1.4-2.5; P < .0001). Pitch velocity was also significantly related with past pain, present pain, and past and/or present pain of the elbow (OR [km/h], 1.1, 1.1, 1.1; 95% CI, 1.0-1.1, 1.0-1.2, 1.1-1.2; P < .0001, P = .002, P < .0001, respectively). Conclusion: Pitch velocity was significantly associated with abnormality of the medial epicondyle and elbow pain. A 10-km/h increase in pitch velocity would increase the risk of medial epicondyle abnormality and medial elbow pain by 3 times.

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Increasing Burden of Youth Baseball Elbow Injuries in US Emergency Departments

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967119845636 ◽

2019 ◽

Vol 7 (5) ◽

pp. 232596711984563 ◽

Cited By ~ 5

Author(s):

David P. Trofa ◽

Kyle K. Obana ◽

Hasani W. Swindell ◽

Brian Shiu ◽

Manish S. Noticewala ◽

...

Keyword(s):

Linear Regression Analysis ◽

Shoulder Injuries ◽

Injury Surveillance System ◽

Baseball Players ◽

Elbow Injury ◽

Youth Athletes ◽

Increased Risk ◽

Youth Baseball ◽

Elbow Injuries ◽

Over Time

Background: Youth athletes are starting sports earlier and training harder. Intense, year-round demands are encouraging early sports specialization under the perception that it will improve the odds of future elite performance. Unfortunately, there is growing evidence that early specialization is associated with increased risk of injury and burnout. This is especially true of pediatric and adolescent baseball players. Purpose/Hypothesis: The purpose of this investigation was to analyze national injury trends of youth baseball players. We hypothesized that while the total number of baseball injuries diagnosed over the past decade would decrease, there would be an increase in adolescent elbow injuries seen nationally. A further hypothesis was that this trend would be significantly greater than other injuries to the upper extremity and major joints. Study Design: Descriptive epidemiology study. Methods: Injury data from the National Electronic Injury Surveillance System, a United States Consumer Product Safety Commission database, were analyzed between January 1, 2006, and December 31, 2016, for baseball players aged ≤18 years. Data were collected on the location of injury, diagnosis, and mechanism of injury. Results: Between 2006 and 2016, an estimated 665,133 baseball injuries occurred nationally. The mean age of the injured players was 11.5 years. The most common injuries diagnosed included contusions (26.8%), fractures (23.6%), and strains and sprains (18.7%). Among major joints, the ankle (25.6%) was most commonly injured, followed by the knee (21.3%), wrist (19.2%), elbow (17.7%), and shoulder (16.2%). The incidence of the ankle, knee, wrist, and shoulder injuries decreased over time, while only the incidence of elbow injuries increased. A linear regression analysis demonstrated that the increasing incidence of elbow injuries was statistically significant against the decreasing trend for all baseball injury diagnoses, as well as ankle, knee, wrist, hand, and finger injuries ( P < .05). Additionally, the only elbow injury mechanism that increased substantially over time was throwing. Conclusion: The current investigation found that while the incidence of baseball injuries sustained by youth players is decreasing, elbow pathology is becoming more prevalent and is more commonly being caused by throwing. Given that the majority of elbow injuries among adolescent baseball players are overuse injuries, these findings underscore the importance of developing strategies to continue to ensure the safety of these youth athletes.

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