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Relationship between humeral retroversion and baseball positions during elementary and junior-high school
Akihiko Hasegawa1, Teruhisa Mihata1, Yasuo Itami1
1Department of Orthopedic Surgery, Osaka Medical College, Takatsuki, Japan.
Journal of Shoulder and Elbow Surgery
|October 30, 2020
Summary
Pitching in youth baseball significantly increases humeral retroversion, especially in the dominant shoulder. This adaptation is linked to repetitive throwing, not injury, in young baseball players.
Area of Science:
- Orthopedics
- Sports Medicine
- Biomechanics
Background:
- Humeral retroversion is greater in the dominant shoulder of baseball players.
- The impact of childhood baseball positions on humeral retroversion is not well understood.
Purpose of the Study:
- To examine the relationship between childhood baseball positions and humeral retroversion.
- To investigate the association between humeral retroversion and shoulder/elbow pain or injury history.
Main Methods:
- 149 male high school baseball players completed questionnaires on positions and injury history.
- Evaluated shoulder range of motion and humeral retroversion using ultrasonography.
- Assessed the correlation between humeral retroversion and shoulder/elbow pain.
Main Results:
- Humeral retroversion was significantly greater in the dominant vs. nondominant shoulder across all player groups.
- Pitchers in elementary and junior high had greater dominant shoulder retroversion than fielders.
- Dominant shoulder retroversion correlated positively with years played as a pitcher; no correlation with pain/injury.
Conclusions:
- Playing pitcher in youth baseball increases dominant shoulder humeral retroversion.
- Increased humeral retroversion is an adaptive response to repetitive throwing, not a pathological change.
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