Impact of Multiple Modes of Visual Occlusion on Static and Dynamic Postural Control
TL;DR
It can be stated that different stroboscopic modes have distinct effects on static and dynamic postural control.
Abstract
Stroboscopic vision (SV) is a novel modality that modulates visual input and can impair postural control due to the resulting visual occlusion. SV tools have multiple levels of visual occlusion (i.e. difficulty) but our understanding of how both instrumented and clinical measures of postural control are impacted by different modes of visual occlusion remain extremely limited. This study aimed to investigate the effects of different modes of SV on instrumented and clinical measures of static and dynamic balance. Three-dimensional ground reaction forces were recorded during both the jump and dominant single-leg balance tasks using a portable Kistler force plate (9286BA; Kistler Instrument Corp, Novi, MI) at a sampling rate of 1200 Hz. Thirty-four healthy individuals performed a single limb static balance task under six visual conditions: eyes open (EO), Mode A, Mode B, Mode C, and Mode D, and eyes closed (EC). SV operated in four modes: both lenses strobing (Mode A), left lens strobing with the right lens opaque (Mode B), right lens strobing with the left lens opaque (Mode C), and alternating strobing between lenses to disrupt binocular vision (Mode D). Static balance was assessed using force plate–derived center of pressure (COP) metrics, including COP velocity and 95% confidence ellipse area, whereas dynamic balance was quantified using the dynamic postural stability index (DPSI) and its directional components. All modes of SV resulted in significantly worse objective static postural control and velocity relative to the EO condition (p < .001). No differences were noted among levels of SV (p > .05) for dynamic postural control. All modes of visual occlusion impair static postural control, but the magnitude of the impairment depends on the outcome measure used. However, these modes did not impair dynamic postural control. In conclusion, it can be stated that different stroboscopic modes have distinct effects on static and dynamic postural control.