Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, Suita, Japan; Research Fellow of Japan Society for the Promotion of Science, Chiyoda-ku, Japan.
Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
J Biomech. 2021 May 24;121:110416. doi: 10.1016/j.jbiomech.2021.110416. Epub 2021 Apr 20.
Pectoralis major (PMa) muscle injuries are becoming more prevalent, and their incidence differs among the PMa regions, i.e., the clavicular, sternal, and abdominal regions. Therefore, identifying the position for effectively lengthening each PMa region is critical in preventing PMa injuries. The purpose of this study was to determine the effective stretching position for each PMa region through shear wave elastography, which can indirectly assess individual muscle lengthening. Fifteen men participated in this study. Twelve stretching positions were compounded with shoulder abductions (45°, 90°, and 135°), pelvic rotation (with or without), shoulder external rotation (with or without), and shoulder horizontal abductions. The shear modulus of each PMa region was measured through shear wave elastography in the stretching positions mentioned above. At the clavicular region, the shear modulus was higher for three stretching positions: shoulder horizontal abduction at 45° abduction during pelvic rotation and shoulder external rotation, shoulder horizontal abduction at 90° abduction, and shoulder horizontal abduction at 90° abduction while considering shoulder external rotation. For the sternal region, the shear modulus was higher in two stretching positions: shoulder horizontal abduction at 90° abduction while adding external rotation, and combination of pelvic rotation and external rotation. For the abdominal region, the shear modulus was higher in the shoulder horizontal abduction at 135° abduction with pelvic and external rotation. These results indicated that the effective stretching position was different for each PMa region.
胸大肌 (PMa) 肌肉损伤越来越常见，其损伤部位在 PMa 的不同区域，即锁骨区、胸骨区和腹部区。因此，确定每个 PMa 区域的有效拉伸位置对于预防 PMa 损伤至关重要。本研究的目的是通过剪切波弹性成像确定每个 PMa 区域的有效拉伸位置，这可以间接评估个体肌肉的拉伸程度。15 名男性参与了这项研究。复合了 12 种拉伸位置，包括肩外展（45°、90°和 135°）、骨盆旋转（带或不带）、肩外旋（带或不带）和肩水平外展。通过剪切波弹性成像测量了上述拉伸位置的每个 PMa 区域的剪切模量。在锁骨区，三种拉伸位置的剪切模量较高：骨盆旋转时肩水平外展 45°并伴肩外旋、肩水平外展 90°、考虑肩外旋时肩水平外展 90°。对于胸骨区，两种拉伸位置的剪切模量较高：肩水平外展 90°并加外旋、骨盆旋转和外旋的组合。对于腹部区，肩水平外展 135°并伴有骨盆和外旋时剪切模量较高。这些结果表明，每个 PMa 区域的有效拉伸位置不同。
