Prado-Rico Janina Manzieri, Alouche Sandra Regina, Sodré Ariani Cardoso, Garbus Rafaela Barroso de Souza Costa, Freitas Sandra Maria Sbeghen Ferreira de
Graduate Program in Physical Therapy, São Paulo City University, Brazil.
Undergraduate Program in Physical Therapy, São Paulo City University, Brazil.
Gait Posture. 2018 Sep;65:15-19. doi: 10.1016/j.gaitpost.2018.06.164. Epub 2018 Jun 28.
Lightly touching the tip of the index finger on an external surface reduces the postural sway during upright standing due to the additional somatosensory information provided by the touch to the postural control system. But when the individuals apply more force, it provides more mechanical support. However, because most of the studies investigated only two levels of force, whether the control mechanisms of postural sway are affected by the different force levels was unknown.
To examine the influence of the magnitude of force (up to 1, 2, 4, 6 or 8 N) applied to the touch bar on the mechanisms used to control the postural sway during quiet standing with eyes open or closed.
Ten young right-handed adults stood for 35 s on a force platform, with feet apart, while touched a rigid bar with different force levels with eyes open or closed. The amplitude and velocity of the center of pressure and its components, Rambling and Trembling trajectories, respectively, related to more supraspinal and spinal control mechanisms, were assessed.
The touch reduced all trajectories, mainly of the Rambling component and with closed eyes. There was a floor effect of the touch force as amplitudes and velocities were minimal at 4 N of force.
The component of postural sway under the supraspinal neural control is more affected by different force magnitudes applied to the touch bar.
将食指指尖轻轻触碰外部表面，由于触摸为姿势控制系统提供了额外的体感信息，可减少直立站立时的姿势晃动。但当个体施加更大的力时，它会提供更多的机械支撑。然而，由于大多数研究仅调查了两个力的水平，姿势晃动的控制机制是否受不同力水平的影响尚不清楚。
研究在睁眼或闭眼安静站立期间，施加在触摸杆上的力的大小（高达1、2、4、6或8牛顿）对控制姿势晃动机制的影响。
10名年轻右利手成年人双脚分开，在力平台上站立35秒，同时在睁眼或闭眼状态下以不同的力水平触摸一根刚性杆。评估了压力中心及其分量的幅度和速度，以及分别与更多脊髓上和脊髓控制机制相关的漫步和颤抖轨迹。
触摸减少了所有轨迹，主要是漫步分量，且在闭眼时更为明显。触摸力存在下限效应，因为在4牛顿力时幅度和速度最小。
脊髓上神经控制下的姿势晃动分量受施加在触摸杆上不同力大小的影响更大。
