Effects of predictive mechanisms on head stability during forward trunk perturbation.
Effects of predictive mechanisms on head stability during forward trunk perturbation.
复制标题
预测机制对躯干前扰动期间头部稳定性的影响。
DOI：
10.1007/s00221-002-1305-4
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Lee,WA
中科院分区：
文献类型：
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作者：
Simoneau,M;Tinker,SW;Hain,TC;Lee,WA
虽然知道很多关于反射和机械的贡献，头部稳定性的控制，知之甚少的预测控制。本实验的目的是确定预测机制的贡献，头部稳定性在空间中，在俯仰平面，在向前躯干扰动。11名站立的健康受试者的躯干被负载滑轮装置向前拉。这种扰动要么是自己触发的，要么是强加的（由实验者触发）。受试者暴露于两种负荷：体重的2%和4%。从头部和躯干运动学，颈部肌肉肌电图，以及使用逆动力学计算的作用在头部上的扭矩推断作用在头颈系统上的扭矩的贡献。结果表明，在两种负荷下，大部分被试的头和躯干在自我触发条件下的运动量都小于施加条件下的运动量。在自触发条件下，没有证据表明预测性颈部反扭矩或颈部肌肉共同收缩增加。这些研究结果表明，大多数受试者通过减少躯干运动和相关的干扰头部的相互作用扭矩来改善头部稳定性。
While much is known about reflex and mechanical contributions to the control of head stability, little is known about predictive control. The goal of this experiment was to determine the contribution of predictive mechanisms to head stability in space, in the pitch plane, during forward trunk perturbations. Eleven standing healthy subjects had their trunk pulled forward by a load-pulley apparatus. The perturbation was either self-triggered or imposed (triggered by the experimenter). Subjects were exposed to two loads: 2% and 4% of their body weight. The contributions of torques acting on the head-neck system were inferred from head and trunk kinematics, neck muscle EMG, and the torques acting on the head, which were computed using inverse dynamics. The results showed that both the head and trunk moved less during the self-triggered than imposed condition during both loads for most of the participants. There was no evidence of predictive neck countertorque or increased neck muscle co-contraction during the self-triggered condition. These findings suggest that most of the subjects improved head stability in the self-triggered condition by reducing trunk motion and the associated interactive torque that perturbed the head.