Sozzi Stefania, Schieppati Marco
Fondazione Salvatore Maugeri (IRCCS), Centro Studi Attività Motorie, Via Salvatore Maugeri 10, 27100 Pavia, Italy.
Fondazione Salvatore Maugeri (IRCCS), Centro Studi Attività Motorie, Via Salvatore Maugeri 10, 27100 Pavia, Italy; Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Via Forlanini 2, 27100 Pavia, Italy.
Neural Plast. 2016;2016:7123609. doi: 10.1155/2016/7123609. Epub 2016 Aug 22.
Training subjects to step in place on a rotating platform while maintaining a fixed body orientation in space produces a posteffect consisting in inadvertent turning around while stepping in place eyes closed (podokinetic after-rotation, PKAR). We tested the hypothesis that voluntary turning around while stepping in place also produces a posteffect similar to PKAR. Sixteen subjects performed 12 min of voluntary turning while stepping around their vertical axis eyes closed and 12 min of stepping in place eyes open on the center of a platform rotating at 60°/s (pretests). Then, subjects continued stepping in place eyes closed for at least 10 min (posteffect). We recorded the positions of markers fixed to head, shoulder, and feet. The posteffect of voluntary turning shared all features of PKAR. Time decay of angular velocity, stepping cadence, head acceleration, and ratio of angular velocity after to angular velocity before were similar between both protocols. Both postrotations took place inadvertently. The posteffects are possibly dependent on the repeated voluntary contraction of leg and foot intrarotating pelvic muscles that rotate the trunk over the stance foot, a synergy common to both protocols. We propose that stepping in place and voluntary turning can be a scheme ancillary to the rotating platform for training body segment coordination in patients with impairment of turning synergies of various origin.
训练受试者在旋转平台上原地踏步，同时在空间中保持固定的身体方向，会产生一种后效应，即闭眼原地踏步时会不自觉地转身（原地踏步后旋转，PKAR）。我们测试了这样一个假设，即原地踏步时的自主转身也会产生类似于PKAR的后效应。16名受试者在以60°/秒旋转的平台中心闭眼围绕垂直轴原地踏步并自主转身12分钟，以及睁眼原地踏步12分钟（预测试）。然后，受试者继续闭眼原地踏步至少10分钟（后效应）。我们记录了固定在头部、肩部和脚部的标记物的位置。自主转身的后效应具有PKAR的所有特征。两种方案中，角速度的时间衰减、踏步节奏、头部加速度以及前后角速度之比相似。两次后旋转都是不自觉发生的。后效应可能取决于腿部和足部内旋转骨盆肌肉的反复自主收缩，这种收缩会使躯干在支撑脚上旋转，这是两种方案共有的一种协同作用。我们提出，原地踏步和自主转身可以作为旋转平台的辅助方案，用于训练各种原因导致转身协同受损患者的身体节段协调性。
