Kian-Bostanabad Sharareh, Azghani Mahmoodreza, Parnianpour Mohammad
Department of Biomedical Engineering, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz, Iran.
Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
Sci Rep. 2025 Mar 5;15(1):7718. doi: 10.1038/s41598-025-87802-1.
Modularity (Muscle synergy) is the concept that has been used to answer the question of how the central nervous system (CNS) coordinates the body's high degrees of freedom. This study aimed to investigate the trunk muscle synergies in symmetrical and asymmetrical positions. Fourteen healthy males participated. Electromyographical activities of 16 muscles were recorded during maximum voluntary isometric contraction (MVIC) in six main directions with two repetitions and maximum voluntary isometric extension (MVIE) of the trunk in 23 different three-dimensional trunk positions. Muscle synergies were extracted separately using non-negative matrix factorization during MVIC (with one/two repetitions) and MVIE. The effect of position changes on synergies was investigated using response surface models and the Pearson correlation coefficient. The findings show that 6 synergies for 6 directions MVIC and 2 synergies for MVIE are suitable with the variance accounted for of 99.65 ± 0.65 96 and 94.14 ± 1.59, respectively. Trial repetition does not affect the synergies. In Conclusion, during the same activity in different positions and trials, the synergy of the main activity is preserved. These show the stability of synergies and their dependence on the activity type. This stability may help to determine the main damage caused and provide appropriate treatment protocol for trunk injuries.
模块化（肌肉协同）是一个被用来回答中枢神经系统（CNS）如何协调身体高度自由度这一问题的概念。本研究旨在调查对称和不对称姿势下的躯干肌肉协同作用。14名健康男性参与了研究。在六个主要方向的最大自主等长收缩（MVIC）过程中，记录了16块肌肉的肌电活动，每个方向重复两次，同时在23个不同的三维躯干位置记录了躯干的最大自主等长伸展（MVIE）。在MVIC（一次/两次重复）和MVIE期间，使用非负矩阵分解分别提取肌肉协同作用。使用响应面模型和皮尔逊相关系数研究位置变化对协同作用的影响。研究结果表明，6个方向MVIC的6种协同作用和MVIE的2种协同作用是合适的，方差解释率分别为99.65±0.65%和94.14±1.59%。试验重复不影响协同作用。总之，在不同位置和试验的相同活动期间，主要活动的协同作用得以保留。这些结果显示了协同作用的稳定性及其对活动类型的依赖性。这种稳定性可能有助于确定主要损伤原因，并为躯干损伤提供适当的治疗方案。
