journal article

Journal Article

Journal of Shoulder and Elbow Surgery. 2025, 34(4), p. 962-970

Prevalence of abnormal ultrasonography findings in the posterosuperior humeral head of asymptomatic collegiate baseball pitchers

Elsevier Inc.

English

2025-04-01

https://doi.org/10.1016/j.jse.2024.07.026

Uchida T., Matsuo T., Sakata J., et al. Prevalence of abnormal ultrasonography findings in the posterosuperior humeral head of asymptomatic collegiate baseball pitchers. Journal of Shoulder and Elbow Surgery, (2024); https://doi.org/10.1016/j.jse.2024.07.026.

Background: The posterosuperior humeral head contacts the glenoid during pitching. While magnetic resonance imaging often detects abnormalities in the posterosuperior humeral head of baseball pitchers, ultrasonography may also be effective in identifying these abnormalities. However, studies on such abnormalities in asymptomatic players are limited. Thus, this study aimed to determine the prevalence of abnormal findings in the humeral head using ultrasonography in asymptomatic collegiate baseball pitchers. Methods: We utilized ultrasonography to assess abnormal findings in the humeral head, defined as a break in continuity or an irregular surface around the infraspinatus insertion, in 33 college baseball pitchers (pitcher group) and 30 college students without experience in overhead sports (control group). For 11 of the 33 pitchers, computed tomography-like images were used to locate the abnormalities. The location was quantitatively identified in the axial plane using a clock system, with the bicipital groove designated as 12 o'clock, and qualitatively assessed in the sagittal plane. Shoulder internal and external rotation ranges of motion (IR and ER ROMs) and humeral retroversion were measured using an inclinometer. The prevalence of abnormalities among the 4 subgroups (throwing and nonthrowing shoulders of the pitcher group and dominant and nondominant shoulders of the control group) was compared using the Fisher's exact test. A paired t-test was also performed to compare the IR and ER ROMs, as well as the humeral retroversion between each group's throwing (dominant) and nonthrowing (nondominant) sides. Results: The prevalence of abnormalities was significantly higher (76%) in the throwing shoulder of the pitcher group than in the other shoulder groups (<.001). The mean position of the humeral head abnormalities in the axial plane was 8:32 ± 0:21 in the clock system, with all abnormalities located at the infraspinatus insertion on the greater tuberosity in the sagittal plane according to CT-like image analysis. While ER ROM and humeral retroversion were greater in the throwing shoulder, IR ROM was less than that in the non-throwing shoulder in the pitcher group (<.001). Conclusion: Ultrasonographic assessments revealed a higher prevalence of abnormalities in humeral head for asymptomatic collegiate baseball pitchers. Repetitive throwing motions may lead not only to adaptations in the ROM of the shoulder joint but also to abnormalities in the humeral head. Thus, ultrasonography may help identify asymptomatic baseball players with physiological internal impingement.

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100570

Prevalence of abnormal ultrasonography findings in the posterosuperior humeral head of asymptomatic collegiate baseball pitchers

Elsevier Inc.

English

2025-04-01

Journal of Shoulder and Elbow Surgery

34

4

962

970

https://doi.org/10.1016/j.jse.2024.07.026

https://hdl.handle.net/11094/100570