ANTICIPATORY POSTURAL CHANGES INDUCED BY ACTIVE UNLOADING AND COMPARISON WITH PASSIVE UNLOADING IN MAN
ANTICIPATORY POSTURAL CHANGES INDUCED BY ACTIVE UNLOADING AND COMPARISON WITH PASSIVE UNLOADING IN MAN
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DOI：
10.1007/bf00581412
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发表时间：
1982-01-01
影响因子：
4.5
通讯作者：
WIESENDANGER, M
中科院分区：
文献类型：
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作者：
HUGON, M;MASSION, J;WIESENDANGER, M
要求坐在椅子上的正常人受试者在0.5或1.0 kg的载荷下保持稳定的肘关节屈曲。实验者被动或对侧手臂主动施加负荷，记录肘关节角度、负荷所施加的力以及双臂肱二头肌和肱三头肌的肌电活动，并取平均值。被动卸载后，减少二头肌肌电图活动，开始举重后50-80毫秒，并通过向上偏转的前臂。在主动卸载的情况下，二头肌EMG活动的减少略微先于卸载的开始（0-30 ms）。主动卸载臂的这种减少与对侧卸载臂的活动几乎同时发生。在这个实验中，卸载前臂保持几乎稳定的位置。当受试者进行卸载时观察到的肘姿势的预期调整似乎在机械扰动期间优化了肢体稳定性。
Normal human subjects, sitting in a chair, were required to maintain stable elbow flexion against loads of 0.5 or 1.0 kg. Unloading was affected passively by the experimenter or actively with the subject''s own contralateral arm. Elbow angle, force exerted by the load and electromyographic (EMG) activity of biceps and triceps muscles of both arms were recorded and averaged. Passive unloading was followed by a reduction of biceps EMG activity, starting 50-80 ms after weight lift, and by an upward deflection of the forearm. With active unloading, a reduction of the biceps EMG activity slightly preceded the onset of unloading (0-30 ms). This reduction of the actively unloaded arm occurred at about the same time as the activity of the contralateral unloading arm. In this experiment, the unloaded forearm maintained an almost stable position. The anticipatory adjustment of elbow posture, observed when unloading was performed by the subject, appears to optimize limb stability during the mechanical perturbation.