Center for Sports Medicine, Hokkaido University Hospital, Kita 14, Nishi 5, Sapporo, Hokkaido, 060-8638, Japan.
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.
Sci Rep. 2022 Feb 25;12(1):3231. doi: 10.1038/s41598-022-06464-5.
The purpose of this study is to evaluate the glenohumeral contact area, center of glenohumeral contact area, and center of humeral head during simulated pitching motion in collegiate baseball pitchers using four-dimensional computed tomography (4D CT). We obtained 4D CT data from the dominant and non-dominant shoulders of eight collegiate baseball pitchers during the cocking motion. CT image data of each joint were reconstructed using a 3D reconstruction software package. The glenohumeral contact area, center of glenohumeral contact area, center of humeral head, and oblateness of humeral head were calculated from 3D bone models using customized software. The center of glenohumeral contact area translated from anterior to posterior during maximum external rotation to maximum internal rotation (0.58 ± 0.63 mm on the dominant side and 0.99 ± 0.82 mm on the non-dominant side). The center of humeral head translated from posterior to anterior during maximum external rotation to maximum internal rotation (0.76 ± 0.75 mm on the dominant side and 1.21 ± 0.78 mm on the non-dominant side). The increase in anterior translation of the center of glenohumeral contact area was associated with the increase in posterior translation of the center of humeral head. Also, the increase in translation of the center of humeral head and glenohumeral contact area were associated with the increase in oblateness of the humeral head. 4D CT analyses demonstrated that the center of humeral head translated in the opposite direction to that of the center of glenohumeral contact area during external rotation to internal rotation in abduction in the dominant and non-dominant shoulders. The oblateness of the humeral head may cause this diametric translation. 4D CT scanning and the software for bone surface modeling of the glenohumeral joint enabled quantitative assessment of glenohumeral micromotion and be used for kinematic evaluation of throwing athletes.
本研究旨在使用四维计算机断层扫描（4D CT）评估大学生棒球投手中模拟投球动作时的盂肱关节接触面积、盂肱关节接触中心和肱骨头中心。我们从 8 名大学生棒球投手的优势肩和非优势肩获得了投球动作时的 4D CT 数据。使用 3D 重建软件包重建每个关节的 CT 图像数据。使用定制软件从 3D 骨骼模型计算盂肱关节接触面积、盂肱关节接触中心、肱骨头中心和肱骨头扁度。在最大外旋到最大内旋过程中，盂肱关节接触中心从前向后平移（优势侧为 0.58±0.63mm，非优势侧为 0.99±0.82mm）。在最大外旋到最大内旋过程中，肱骨头中心从后向前平移（优势侧为 0.76±0.75mm，非优势侧为 1.21±0.78mm）。盂肱关节接触中心前向平移的增加与肱骨头中心后向平移的增加相关。此外，肱骨头中心和盂肱关节接触中心的平移增加与肱骨头扁度的增加相关。4D CT 分析表明，在优势肩和非优势肩的外展内收旋转过程中，肱骨头中心向与盂肱关节接触中心相反的方向平移。肱骨头的扁度可能导致这种直径平移。4D CT 扫描和盂肱关节骨表面建模软件可对盂肱关节微动进行定量评估，并可用于投掷运动员的运动学评估。
