Centro Studi Attività Motorie (CSAM), Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy.
Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Pavia, Italy.
Neural Plast. 2019 Mar 11;2019:7129279. doi: 10.1155/2019/7129279. eCollection 2019.
Unilateral axial muscle vibration, eliciting a proprioceptive volley, is known to incite steering behavior. Whole-body rotation while stepping in place also occurs as an after-effect of stepping on a circular treadmill (podokinetic after-rotation, PKAR). Here, we tested the hypothesis that PKAR is modulated by axial muscle vibration. If both phenomena operate through a common pathway, enhancement or cancellation of body rotation would occur depending on the stimulated side when vibration is administered concurrently with PKAR. Seventeen subjects participated in the study. In one session, subjects stepped in place eyes open on the center of a platform that rotated counterclockwise 60°/s for 10 min. When the platform stopped, subjects continued stepping in place blindfolded. In other session, a vibratory stimulus (100 Hz, 2 min) was administered to right or left paravertebral muscles at lumbar level at two intervals during the PKAR. We computed angular body velocity and foot step angles from markers fixed to shoulders and feet. During PKAR, all subjects rotated clockwise. Decreased angular velocity was induced by right vibration. Conversely, when vibration was administered to the left, clockwise rotation velocity increased. The combined effect on body rotation depended on the time at which vibration was administered during PKAR. Under all conditions, foot step angle was coherent with shoulder angular velocity. PKAR results from continuous asymmetric input from the muscles producing leg rotation, while axial muscle vibration elicits a proprioceptive asymmetric input. Both conditioning procedures appear to produce their effects through a common mechanism. We suggest that both stimulations would affect our straight ahead by combining their effects in an algebraic mode.
单侧轴向肌肉振动，诱发本体感受反射，已知可引起转向行为。在原地踏步时进行全身旋转也会作为在圆形跑步机上踏步（运动觉后旋转，PKAR）的后效发生。在这里，我们测试了 PKAR 受轴向肌肉振动调制的假设。如果这两种现象通过共同途径运作，那么当振动与 PKAR 同时进行时，根据刺激侧，身体旋转的增强或取消将会发生。17 名受试者参加了这项研究。在一个实验中，受试者睁开眼睛，在一个以 60°/s 的速度逆时针旋转 10 分钟的平台中心原地踏步。当平台停止时，受试者继续蒙住眼睛原地踏步。在另一个实验中，在 PKAR 期间的两个时间间隔，将振动刺激（100Hz，2 分钟）施加到腰部的左右脊柱旁肌肉。我们从固定在肩部和脚部的标记计算身体角速度和脚步角度。在 PKAR 期间，所有受试者都顺时针旋转。右侧振动会导致角速度降低。相反，当振动施加到左侧时，顺时针旋转速度增加。对身体旋转的综合影响取决于振动在 PKAR 期间施加的时间。在所有条件下，脚步角度与肩部角速度一致。PKAR 是由产生腿部旋转的肌肉连续不对称输入引起的，而轴向肌肉振动则会产生本体感受不对称输入。这两种调节程序似乎都是通过共同的机制产生效果的。我们建议，这两种刺激都会通过以代数模式结合它们的效果来影响我们的前进方向。
