Graci Valentina, Elliott David B, Buckley John G
Vision and Mobility Laboratory, Bradford School of Optometry and Vision Science, University of Bradford, Bradford, UK.
Gait Posture. 2009 Oct;30(3):370-4. doi: 10.1016/j.gaitpost.2009.06.011. Epub 2009 Jul 22.
The importance of peripheral visual cues in the control of minimum-foot-clearance during overground locomotion on a clear path was investigated. Eleven subjects walked at their natural speed whilst wearing goggles providing four different visual conditions: upper occlusion, lower occlusion, circumferential-peripheral occlusion and full vision. Results showed that under circumferential-peripheral occlusion, subjects were more cautious and increased minimum-foot-clearance and decreased walking speed and step length. The minimum-foot-clearance increase can be interpreted as a motor control strategy aiming to safely clear the ground when online visual exproprioceptive cues from the body are not available. The lack of minimum-foot-clearance increase in lower occlusion suggests that the view of a clear pathway from beyond two steps combined with visual exproprioception and optic flow in the upper field were adequate to guide gait. A suggested accompanying safety strategy of reducing the amount of variability of minimum-foot-clearance under circumferential-peripheral occlusion conditions was not found, likely due to the lack of online visual exproprioceptive cues provided by the peripheral visual field for fine-tuning foot trajectory.
研究了在清晰路径上进行地面行走时，周边视觉线索对控制最小离地间隙的重要性。11名受试者戴着护目镜以自然速度行走，护目镜提供四种不同的视觉条件：上视野遮挡、下视野遮挡、周边视野环形遮挡和全视野。结果表明，在周边视野环形遮挡条件下，受试者更加谨慎，增加了最小离地间隙，降低了行走速度和步长。最小离地间隙的增加可以解释为一种运动控制策略，旨在在无法获得来自身体的在线视觉本体感受线索时安全地越过地面。在下视野遮挡时最小离地间隙没有增加，这表明两步以外的清晰路径视野与上视野中的视觉本体感受和光流相结合足以指导步态。未发现一种建议的伴随安全策略，即在周边视野环形遮挡条件下减少最小离地间隙的变化量，这可能是由于周边视野缺乏用于微调足部轨迹的在线视觉本体感受线索。
