Voluntary toe-walking gait initiation:: electromyographical and biomechanical aspects
Voluntary toe-walking gait initiation:: electromyographical and biomechanical aspects
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DOI：
10.1007/s00221-002-1254-y
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发表时间：
2002-12-01
影响因子：
2
通讯作者：
Brenière, Y
中科院分区：
文献类型：
--
作者：
Couillandre, A;Maton, B;Brenière, Y
本研究旨在探讨脚趾行走步态启动的生物力学约束，以及与已有文献记载的脚跟-脚趾步行步态启动相比，运动程序的相关变化。七名健康的受试者自愿参加了这项研究。步态在测力台上以三种自选的速度条件启动，分别是控制情景下的自然直立姿势(CS)和测试情景下的抬起脚跟姿势(TS)。记录双侧肢体比目鱼肌(SOL)和胫前肌(TA)的表面肌电活动。我们分析了脚跟离开体位对肌电模式和生物力学活动的影响。无论速度条件如何，与CS组相比，TS组的足底压力中心最初位于踝关节轴前方，SOL和TA肌电活动增加。与CS相比，TS患者表达控制步态启动的运动程序的肌电模式发生了改变，并诱导了脚趾离开前的预期姿势调整(APA)的适应。APA持续时间的延长允许TS组的受试者在预期运动结束时和第一步结束时达到与CS组相似的步态速度。与CS组一样，TS组在第一步结束时的重心速度与第一步结束时的CG速度是一致的，这仍然是APA期间TA肌肉作用的结果，但也可能是其他联合肌肉作用的结果。
This study was carried out to investigate the biomechanical constraints of toe-walking gait initiation and the associated changes in motor program compared to the well documented heel-toe walking gait initiation. Seven healthy subjects volunteered for this study. Gait was initiated on a force platform, at three self-selected speed conditions, from an erect spontaneous posture in the control situation (CS) and from a posture with heels raised in the test situation (TS). Surface electromyographical (EMG) activities of muscles soleus (Sol) and tibialis anterior (TA) were recorded on both limbs. We analysed the consequences of the heel-off posture on EMG patterns and biomechanical activities. Whatever the speed condition, the centre of foot pressure was initially located more ahead of the ankle axis in TS than in CS, with an increased Sol and TA EMG activity. The EMG pattern which expresses the motor program governing gait initiation was modified in TS in comparison to CS and induced adaptations of the anticipatory postural adjustments (APA) that precede toe-off of the stepping limb. A lengthening of the APA duration allowed the subjects in TS to reach a gait velocity similar to the one obtained in CS at the end of the anticipatory movements and also at the end of the first step. In TS, the velocity of the centre of gravity at time of toe-off covaried, as in CS, with CG velocity at the end of the first step, still resulting from TA muscular actions during the APA but also probably from other combined muscular actions.