Tracy Brian L
Department of Health and Exercise Science, 220 Moby-B Complex, Colorado State University, Fort Collins, CO 80523-1582, USA.
Hum Mov Sci. 2007 Dec;26(6):796-807. doi: 10.1016/j.humov.2007.07.001. Epub 2007 Sep 4.
The visual correction employed during isometric contractions of large proximal muscles contributes variability to the descending command and alters fluctuations in muscle force. This study explored the contribution of visuomotor correction to isometric force fluctuations for the more distal dorsiflexor (DF) and plantarflexor (PF) muscles of the ankle. Twenty-one healthy adults performed steady isometric contractions with the DF and PF muscles both with (VIS) and without (NOVIS) visual feedback of the force. The target forces exerted ranged from 2.5% to 80% MVC. The standard deviation (SD) and coefficient of variation (CV) of force was measured from the detrended (drift removed) VIS and NOVIS steadiness trials. Removal of VIS reduced the CV of force by 19% overall. The reduction in fluctuations without VIS was significant across a large range of target forces and was more consistent for the PF than the DF muscles. Thus, visuomotor correction contributes to the variability of force during isometric contractions of the ankle dorsiflexors and plantarflexors.
在大的近端肌肉等长收缩过程中采用的视觉矫正会给下行指令带来变异性,并改变肌肉力量的波动。本研究探讨了视觉运动矫正对踝关节更远端的背屈肌(DF)和跖屈肌(PF)等长力量波动的影响。21名健康成年人在有(VIS)和无(NOVIS)力量视觉反馈的情况下,对DF和PF肌肉进行稳定的等长收缩。施加的目标力量范围为最大自主收缩(MVC)的2.5%至80%。从去除趋势(去除漂移)的VIS和NOVIS稳定性试验中测量力量的标准差(SD)和变异系数(CV)。去除VIS后,力量的CV总体降低了19%。在大范围的目标力量中,无VIS时波动的降低是显著的,并且对于PF肌肉比DF肌肉更一致。因此,视觉运动矫正会导致踝关节背屈肌和跖屈肌等长收缩过程中力量的变异性。