Effect of postural differences on the activation of intrinsic foot muscles during ramp-up toe flexion in young men
Effect of postural differences on the activation of intrinsic foot muscles during ramp-up toe flexion in young men
复制标题
DOI：
10.1016/j.gaitpost.2023.03.015
复制
发表时间：
2023-03-28
期刊：
影响因子：
2.4
通讯作者：
Urabe, Yukio
中科院分区：
文献类型：
--
作者：
Komiya, Makoto;Maeda, Noriaki;Urabe, Yukio
背景：内在足部肌肉锻炼用于临床和体育实践中，以提高性能。站姿时脚趾屈曲产生的力大于坐姿；尽管如此，在力量产生过程中激活内在足部肌肉的机制以及这两种姿势之间是否存在差异仍不清楚。研究问题：在逐渐产生力的过程中，站立和坐姿是否会影响足部内在肌肉的活动？方法：17名男性参与了以实验室为基础的横断面研究。每个参与者在坐姿和站立姿势中执行从0%到80%的最大脚趾屈肌力量（MTFS）的力增强脚趾屈任务。通过计算均方根（RMS）确定任务过程中获得的高密度表面肌电信号。此外，每10% MTFS计算20- 80% MTFS下的修正熵和变异系数（CoV）。结果：两种体位的RMS存在交互作用（p < 0.01）。事后分析显示，在60% MTFS （67.53 +/- 15.91 vs 54.64 +/- 19.28%最大自愿收缩[MVC]， p = 0.03）、70% MTFS （78.11 +/- 12.93 vs 63.28 +/- 18.65% MVC, p = 0.01）和80% MTFS （81.78 +/- 14.07 vs 66.90 +/- 20.32% MVC, p = 0.02）下，站立姿势的内在足部肌肉活动显著高于坐姿。站立姿态下，80% MTFS时的修正熵低于20% MTFS时（p = 0.03）， 80% MTFS时的冠状病毒高于20% MTFS时（p = 0.03）。意义：这些结果表明，姿势选择是重要的高强度运动的内在足部肌肉，如阻力训练。因此，在适当的负重情况下，如站立姿势，提高与脚趾屈肌力量有关的表现可能更有效
Background: Intrinsic foot muscle exercises are used in clinical and sports practice to improve performance. Force generation during toe flexion is greater in the standing posture than in the sitting posture; nonetheless, the mechanism underlying the activation of intrinsic foot muscles during force generation and whether there exists a difference between these two postures still remain unclear. Research question: Are the activities of intrinsic foot muscles affected by standing and sitting postures during gradual force generation? Methods: Seventeen men participated in the laboratory based cross-sectional study. Each participant performed a force ramp-up toe flexion task from 0% to 80% of the maximal toe flexor strength (MTFS) in sitting and standing postures. High-density surface electromyography signals obtained during the task were determined by calcu-lating the root mean square (RMS). Additionally, modified entropy and coefficient of variation (CoV) were calculated at 20-80 % MTFS for each 10 % MTFS. Results: The RMS between the two postures indicated an interaction effect (p < 0.01). Post-hoc analyses revealed that intrinsic foot muscle activity during the ramp-up task was significantly higher in the standing posture than in the sitting posture at 60 % MTFS (67.53 +/- 15.91 vs 54.64 +/- 19.28 % maximal voluntary contraction [MVC], p = 0.03), 70 % MTFS (78.11 +/- 12.93 vs 63.28 +/- 18.65 % MVC, p = 0.01), and 80 % MTFS (81.78 +/- 14.07 vs 66.90 +/- 20.32 % MVC, p = 0.02). In the standing posture, the modified entropy at 80 % MTFS was lower than that at 20 % MTFS (p = 0.03), and the CoV at 80 % MTFS was higher than that at 20 % MTFS (p = 0.03). Significance: These results indicated that posture selection is important for high-intensity exercises of the intrinsic foot muscles, such as resistance training. Thus, improving performance related to toe flexor strength might be more effective when conducted under adequate weight-bearing situations, such as in the standing posture