Gantchev G N, Dimitrova D M
Institute of Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Int J Psychophysiol. 1996 Apr-May;22(1-2):117-22. doi: 10.1016/0167-8760(96)00016-5.
This study aims to investigate the pattern of anticipatory postural adjustments associated with arm movements during balancing on unstable support surface as a mechanism of coordination between movement and posture in this specific motor task. The experiments were arranged in two series: (1) the subjects stood on a force platform, and (2) on unstable platform (see-saw). They performed self-paced arm elevations as fast as possible for each support condition. EMG activity of deltoideus anterior (DA), soleus (SOL), tibialis anterior (TA), biceps femoris (BF) and erector spinae (ES) muscles were recorded. The mean EMG of SOL and TA muscles during balancing and during the last 100 ms prior to DA EMG onset were measured. For both series the anticipatory postural adjustment of BF preceded the ES activation. During balancing on see-saw the following differences from the stable condition were found: (1) co-contraction of SOL and TA muscles; (2) significantly earlier recruitment of BF; (3) delayed related activity of ES; (4) decrease of SOL and increase of TA mean EMG activities during balancing and just prior to the onset of DA EMG activity. These data showed that posture control during balancing on unstable support surface consists mainly in adapting the motor program according to the postural requirements rather than in changes of the postural strategy.
本研究旨在探究在不稳定支撑面上保持平衡时与手臂运动相关的预期姿势调整模式，以此作为这一特定运动任务中运动与姿势协调的一种机制。实验分为两个系列：（1）受试者站在测力平台上，（2）站在不稳定平台（跷跷板）上。在每种支撑条件下，他们尽可能快地进行自定节奏的手臂上举动作。记录三角肌前束（DA）、比目鱼肌（SOL）、胫骨前肌（TA）、股二头肌（BF）和竖脊肌（ES）的肌电图活动。测量了平衡期间以及DA肌电图开始前最后100毫秒内SOL和TA肌肉的平均肌电图。在两个系列中，BF的预期姿势调整均先于ES的激活。在跷跷板上保持平衡时，发现与稳定状态有以下差异：（1）SOL和TA肌肉的共同收缩；（2）BF的募集明显更早；（3）ES的相关活动延迟；（4）在平衡期间以及DA肌电图活动开始前，SOL的平均肌电图活动下降，TA的平均肌电图活动增加。这些数据表明，在不稳定支撑面上保持平衡时的姿势控制主要在于根据姿势要求调整运动程序，而非姿势策略的改变。
