Sousa Andreia S P, Tavares João Manuel
Escola Superior de Tecnologia da Saude do Instituto Politecnico do Porto, Area Cientifica de Fisioterapia / Centro de Estudos de Movimento e Actividade Humana, Vila Nova de Gaia, Portugal.
Motor Control. 2012 Oct;16(4):480-92. doi: 10.1123/mcj.16.4.480. Epub 2012 May 15.
This study aims to assess the influence of gait speed (manipulated through cadence) on muscle activity patterns and activation degree during stance.
Thirty-five healthy individuals participated in this study. Surface electromyographic activity from the gastrocnemius medialis (GM), gluteus maximus (GMax), biceps femoris (BF) and rectus femoris (RF) was acquired with subjects walking at three different speeds.
Speed influenced: (1) relative motor activity patterns at heel strike, midstance-propulsion transition and propulsion; (2) the activity level of RF, GMax, GM and BF, in decreasing order, with higher activity at the fastest and slowest speeds.
In general, muscle activity was higher at the fastest and slowest speeds than at the self-selected speed and only the activity of the main actions in each subphase remained stable. These findings suggest that gait speeds different from the self-selected speed influence not only activity levels but also relative muscle activity patterns. As a result, caution is advised when choosing standard speeds in gait studies, as this can lead to increased variability in relative muscle activity patterns.
本研究旨在评估步态速度(通过步频控制)对站立期肌肉活动模式及激活程度的影响。
35名健康个体参与了本研究。在受试者以三种不同速度行走时,采集了腓肠肌内侧头(GM)、臀大肌(GMax)、股二头肌(BF)和股直肌(RF)的表面肌电活动。
速度影响:(1)足跟触地、支撑中期 - 推进转换期及推进期的相对运动活动模式;(2)RF、GMax、GM和BF的活动水平,从高到低排列,在最快和最慢速度时活动更高。
总体而言,最快和最慢速度时的肌肉活动高于自选速度时,且每个子阶段主要动作的活动仅保持稳定。这些发现表明,不同于自选速度的步态速度不仅影响活动水平,还影响相对肌肉活动模式。因此,在步态研究中选择标准速度时应谨慎,因为这可能导致相对肌肉活动模式的变异性增加。