Penedo Tiago, Polastri Paula Favaro, Rodrigues Sérgio Tosi, Santinelli Felipe Balistieri, Costa Elisa de Carvalho, Imaizumi Luis Felipe Itikawa, Barbieri Ricardo Augusto, Barbieri Fabio Augusto
Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Graduate Program in Human Movement, School of Sciences, São Paulo State University (UNESP), Bauru, São Paulo, Brazil.
Department of Physical Education, Laboratory of Information, Vision and Action (LIVIA), Graduate Program in Human Movement, School of Sciences, São Paulo State University (UNESP), Bauru, São Paulo, Brazil.
PLoS One. 2021 Feb 25;16(2):e0247395. doi: 10.1371/journal.pone.0247395. eCollection 2021.
The aim of this study was to investigate the effects of ankle and hip muscle fatigue on motor adjustments (experiment 1) and symmetry (experiment 2) of postural control during a quiet standing task. Twenty-three young adults performed a bipedal postural task on separate force platforms, before and after a bilateral ankle and hip muscle fatigue protocol (randomized). Ankle and hip muscles were fatigued separately using a standing calf raise protocol (ankle fatigue) on a step and flexion and extension of the hip (hip fatigue) sitting on a chair, at a controlled movement frequency (0.5Hz), respectively. In both experiments, force, center of pressure, and electromyography parameters were measured. The symmetry index was used in experiment 2 to analyze the postural asymmetry in the parameters. Our main findings showed that muscle fatigue impaired postural stability, regardless of the fatigued muscle region (i.e., ankle or hip). In addition, young adults used an ankle motor strategy (experiment 1) before and after both the ankle and hip muscle fatigue protocols. Moreover, we found increased asymmetry between the lower limbs (experiment 2) during the quiet standing task after muscle fatigue. Thus, we can conclude that the postural motor strategy is not muscle fatigue joint-dependent and a fatigue task increases postural asymmetry, regardless of the fatigued region (hip or ankle). These findings could be applied in sports training and rehabilitation programs with the objective of reducing the fatigue effects on asymmetry and improving balance.
本研究的目的是调查踝关节和髋关节肌肉疲劳对安静站立任务期间姿势控制的运动调整（实验1）和对称性（实验2）的影响。23名年轻人在双侧踝关节和髋关节肌肉疲劳方案（随机）前后，分别在独立的测力平台上进行双足姿势任务。分别使用台阶上的站立提踵方案（踝关节疲劳）和坐在椅子上以受控运动频率（0.5Hz）进行髋关节屈伸（髋关节疲劳）来使踝关节和髋关节肌肉疲劳。在两个实验中，均测量了力、压力中心和肌电图参数。实验2中使用对称指数来分析参数中的姿势不对称性。我们的主要研究结果表明，无论疲劳的肌肉区域（即踝关节或髋关节）如何，肌肉疲劳都会损害姿势稳定性。此外，年轻人在踝关节和髋关节肌肉疲劳方案前后均采用踝关节运动策略（实验1）。此外，我们发现肌肉疲劳后安静站立任务期间下肢之间的不对称性增加（实验2）。因此，我们可以得出结论，姿势运动策略不依赖于肌肉疲劳的关节，并且疲劳任务会增加姿势不对称性，无论疲劳区域是髋关节还是踝关节。这些发现可应用于体育训练和康复计划，以减少疲劳对不对称性的影响并改善平衡。
