Hiraoka Koichi, Gonno Shintaro, Inomoto Ryota
College of Health and Human Sciences, Osaka Prefecture University, Habikino City 583-8555, Japan.
Brain Sci. 2020 May 22;10(5):317. doi: 10.3390/brainsci10050317.
The present study examined whether the left posterior parietal cortex contributes to the selection process for the initial swing leg in gait initiation. Healthy humans initiated the gait in response to an auditory start cue. Transcranial magnetic stimulation (TMS) was given over P3, P4, F3 or F4 simultaneously, with the auditory start cue, in the on-TMS condition. A coil was placed over one of the four TMS sites, but TMS was not given in the off-TMS condition. The probability of right leg selection in the on-TMS condition was significantly lower than in the off-TMS condition when the coil was placed over P3, indicating that the left posterior parietal cortex contributes to the selection process of the initial swing leg of gait initiation. The latency of the anticipatory postural adjustment for gait initiation with the left leg was shortened by TMS over F4 or P4, but with the right leg was shortened by TMS over P3 or P4. Thus, the cortical process affecting the time taken to execute the motor process of gait initiation with the right leg may be related to the selection process of the initial swing leg of gait initiation.
本研究探讨了左后顶叶皮层是否参与步态起始时初始摆动腿的选择过程。健康受试者在听到听觉起始提示后开始行走。在经颅磁刺激（TMS）开启条件下，与听觉起始提示同时，在P3、P4、F3或F4部位施加TMS。线圈置于四个TMS部位之一，但在TMS关闭条件下不施加TMS。当线圈置于P3上方时，TMS开启条件下选择右腿的概率显著低于TMS关闭条件，表明左后顶叶皮层参与了步态起始时初始摆动腿的选择过程。F4或P4部位的TMS缩短了左腿起始步态的预期姿势调整潜伏期，而P3或P4部位的TMS缩短了右腿起始步态的预期姿势调整潜伏期。因此，影响右腿执行步态起始运动过程所需时间的皮层过程可能与步态起始时初始摆动腿的选择过程有关。
