Department of Physical Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Eur J Appl Physiol. 2012 Oct;112(10):3495-502. doi: 10.1007/s00421-012-2330-z.
The purpose of this study was to investigate the effects of unilateral muscle fatigue induced on the hip flexors/extensors or the ankle plantar/dorsiflexors on unipedal postural stability under different visual conditions. Twenty-four healthy young women completed 2 testing sessions 1 week apart with a randomized order assigned according to the muscles tested. During each session, one set of muscle groups was fatigued using isokinetic contractions: ankle plantar/dorsi flexors or hip flexor/extensors. Postural stability was assessed during trials of unilateral stance on a force plate before and after the fatigue protocol. 10 s into the trial, subjects were asked to close their eyes. Mean velocity, the area of the 95% confidence ellipse, and standard deviation of velocity in anteroposterior and mediolateral directions of center of pressure displacements were calculated for two periods of 5 s, immediately before and 1 s after the eyes closure. The results of the repeated measures ANOVAs showed a significant fatigue-by-fatigue segment by visual condition interaction for the CoP parameters. When the vision was removed, the interaction between fatigue and fatigue segment was significant for the CoP parameters. In conclusion, fatigue in both proximal and distal musculature of the lower extremity yielded decreased postural stability during unipedal quiet standing in healthy young women. This effect was more accentuated when visual information was eliminated. Withdrawing vision following fatigue to the proximal musculature, led to a significantly greater impairment of postural stability compared to the fatigue of more distal muscles.
本研究旨在探讨单侧肌肉疲劳对髋关节屈肌/伸肌或踝关节跖屈/背屈肌的影响，以及在不同视觉条件下对单足姿势稳定性的影响。24 名健康年轻女性在 1 周内完成了 2 次测试，测试顺序根据测试的肌肉随机分配。在每次测试中，使用等速收缩对一组肌肉进行疲劳：踝关节跖屈/背屈肌或髋关节屈肌/伸肌。在疲劳方案前后，在测力板上单脚站立试验期间评估姿势稳定性。试验开始后 10 秒，要求受试者闭眼。在闭眼前和闭眼后 1 秒，计算中心压力位移前-后和左-右方向的平均速度、95%置信椭圆面积和速度标准差，共 5 秒。重复测量方差分析的结果显示，姿势稳定性参数的疲劳与疲劳部位与视觉条件之间存在显著的交互作用。当视觉信息被移除时，姿势稳定性参数的疲劳与疲劳部位之间存在显著的交互作用。结论是，在健康年轻女性的单脚静立中，下肢近端和远端肌肉的疲劳都会导致姿势稳定性降低。当视觉信息被消除时，这种影响更为明显。与疲劳更为远端的肌肉相比，疲劳近端肌肉后，对姿势稳定性的损害明显更大。
