Associations between Years of Pitching Experience and Injury Precursors in a Cohort of Little League Baseball Pitchers

Background The effects of repetitive throwing on the shoulders of developing athletes are not well understood because of the paucity of data describing the biomechanics of youth pitchers and the plasticity of the developing skeleton. Hypothesis The direction and magnitude of the stresses that exist at the proximal humeral physis during the fastball pitching motion are consistent with the development of proximal humeral epiphysiolysis (Little League shoulder) and/or humeral retrotorsion. Study Design Descriptive laboratory study. Methods A total of 14 elite youth baseball pitchers (mean age, 12.1 ± 0.4 years) were filmed from the front and dominant side while throwing fastballs in a simulated game. The net force and torque acting on the humerus throughout the throwing motion were calculated using standard biomechanical techniques. Results The external rotation torque about the long axis of the humerus reached a peak value of 17.7 ± 3.5 N.m (2.7% ± 0.3% body weight × height) just before maximum shoulder external rotation. A shoulder distraction force of 214.7 ± 47.2 N (49.8% ± 8.3% body weight) occurred at, or just after, ball release. Conclusion Shear stress arising from the high torque late in the arm-cocking phase is large enough to lead to deformation of the weak proximal humeral epiphyseal cartilage, causing either humeral retrotorsion or proximal humeral epiphysiolysis over time. The stresses generated by the external rotation torque are much greater than those caused by distraction forces generated during the pitching motion of youth baseball pitchers. Clinical Relevance The motion of throwing fastballs by youth baseball pitchers results in force components consistent with proposed mechanisms for 2 clinical entities.

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Opening of the Season: Little League Baseball Pro and Con

PEDIATRICS ◽

10.1542/peds.50.2.341 ◽

1972 ◽

Vol 50 (2) ◽

pp. 341-341

Author(s):

Harold M. Maller

Keyword(s):

Little League ◽

Arm Injuries ◽

Baseball Pitchers ◽

February Issue

Drs. Torg et al. have thrown us a curve with their article in the February issue of Pediatrics on arm injuries in young baseball pitchers. Having referred to "the effect of competitive pitching" in their title, they have proceeded to discuss a group of boys who, they would have us believe, played baseball "for the sake of recreation rather than competition." If one could imagine that such a group of boys had been found, then the authors have failed to investigate what they claim to have investigated.

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The Association of Sport Participation Behaviors with Throwing Arm Health in Little League Baseball Pitchers

JSES Reviews, Reports, and Techniques ◽

10.1016/j.xrrt.2021.02.001 ◽

2021 ◽

Author(s):

Eric G. Post ◽

Michael D. Rosenthal ◽

Andrew T. Pennock ◽

Mitchell J. Rauh

Keyword(s):

Sport Participation ◽

Little League ◽

Baseball Pitchers

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Current Workload Recommendations in Baseball Pitchers: A Systematic Review

The American Journal of Sports Medicine ◽

10.1177/0363546519831010 ◽

2019 ◽

Vol 48 (1) ◽

pp. 229-241 ◽

Cited By ~ 1

Author(s):

Neil K. Bakshi ◽

Paul M. Inclan ◽

Jacob M. Kirsch ◽

Asheesh Bedi ◽

Cristine Agresta ◽

...

Keyword(s):

High School ◽

Systematic Review ◽

Injury Rate ◽

Current Evidence ◽

Professional Baseball ◽

High Quality Research ◽

Baseball Players ◽

Little League ◽

Increased Risk ◽

Baseball Pitchers

Background: Several recommendations have been made regarding pitch counts and workload for baseball players of different levels, including Little League, high school, collegiate, and professional baseball. However, little consensus is found in the literature regarding the scientific basis for many of these recommendations. Purpose: The primary purpose of this study was to summarize the evidence regarding immediate and long-term musculoskeletal responses to increasing pitching workload in baseball pitchers of all levels. A secondary purpose of this review was to evaluate the extent to which workload influences injury and/or performance in baseball pitchers. Study Design: Systematic review. Methods: We performed a systematic search in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies addressing physiologic and/or pathologic musculoskeletal changes in response to a quantifiable pitching workload. We included studies examining the effects of pitching workload on performance, injury rate, and musculoskeletal changes in Little League, high school, collegiate, and professional baseball players. Results: We identified 28 studies that met our inclusion and exclusion criteria: 16 studies regarding Little League and high school pitchers and 12 studies regarding collegiate and professional pitchers. The current evidence presented suggests that increased pitching workload may be associated with an increased risk of pain, injury, and arm fatigue in Little League and high school pitchers. However, little consensus was found in the literature regarding the association between pitching workload and physiologic or pathologic changes in collegiate and professional pitchers. Conclusion: Evidence, although limited, suggests the use of pitch counts to decrease injury rates and pain in Little League and high school baseball pitchers. However, further research must be performed to determine the appropriate number of pitches (or throws) for players of different ages. This systematic review reported conflicting evidence regarding the use of pitch counts in college and professional baseball. Future high-quality research is required to determine the role, if any, of pitch counts for collegiate and professional pitchers.

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