Five basic muscle activation patterns account for muscle activity during human locomotion
Five basic muscle activation patterns account for muscle activity during human locomotion
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DOI：
10.1113/jphysiol.2003.057174
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发表时间：
2004-04-01
影响因子：
5.5
通讯作者：
Lacquaniti, F
中科院分区：
文献类型：
--
作者：
Ivanenko, YP;Poppele, RE;Lacquaniti, F
在步态周期中，个体肌肉的肌电图（EMG）活动模式表现出大量的主体间、肌肉间和上下文相关的变异性。在这里，我们研究了共同的基本模式的问题，通过应用因子分析，在不同的步行速度和重力负荷下获得的一组EMG记录。为此，健康受试者被要求在跑步机上以1，2，3和5 km h（-1）的速度行走，以及使用安全带支撑体重的35-95%。我们记录了12-16个同侧腿部和躯干肌肉使用表面和肌肉内记录，并确定平均值，每个记录的标准化EMG为10-15个连续的步骤周期。我们确定了五个基本的潜在因素或组成波形，可以占约90%的总波形变化在不同的肌肉在正常步态。此外，虽然个别肌肉的激活模式可能会随着速度和重力负荷而发生显着变化，但肢体运动学和基本EMG分量仅显示有限的变化。因此，我们发现了所有五个因素的系统相移，其速度与挥杆阶段开始时的相移方向相同。根据离地事件对因素进行计时的这种趋势支持步态周期生成的起源是推进而不是脚跟撞击事件的想法。步行速度和体重卸载的因素的基本不变性意味着一些振荡回路驱动主动肌肉产生运动学。这些基本成分到肌肉的灵活和动态分布可能是由取决于运动的运动学和动力学需求的各种下行和本体感受信号引起的。
An electromyographic (EMG) activity pattern for individual muscles in the gait cycle exhibits a great deal of intersubject, intermuscle and context-dependent variability. Here we examined the issue of common underlying patterns by applying factor analysis to the set of EMG records obtained at different walking speeds and gravitational loads. To this end healthy subjects were asked to walk on a treadmill at speeds of 1, 2,3 and 5 km h(-1) as well as when 35-95% of the body weight was supported using a harness. We recorded from 12-16 ipsilateral leg and trunk muscles using both surface and intramuscular recording and determined the average, normalized EMG of each record for 10-15 consecutive step cycles. We identified five basic underlying factors or component waveforms that can account for about 90% of the total waveform variance across different muscles during normal gait. Furthermore, while activation patterns of individual muscles could vary dramatically with speed and gravitational load, both the limb kinematics and the basic EMG components displayed only limited changes. Thus, we found a systematic phase shift of all five factors with speed in the same direction as the shift in the onset of the swing phase. This tendency for the factors to be timed according to the lift-off event supports the idea that the origin of the gait cycle generation is the propulsion rather than heel strike event. The basic invariance of the factors with walking speed and with body weight unloading implies that a few oscillating circuits drive the active muscles to produce the locomotion kinematics. A flexible and dynamic distribution of these basic components to the muscles may result from various descending and proprioceptive signals that depend on the kinematic and kinetic demands of the movements.