Delayed Postural Responses to Fear of Falling During Gait Initiation in Low Vision: Insights from Virtual-Reality-Based Fear Simulation

<b>Purpose:</b> This study aimed to quantify the severity of fear of falling (FOF) in people with low vision (LV) compared with age-gender-matched healthy individuals during gait initiation (GI). <b>Methods:</b> A total of 14 adults with LV and 14 age-gender-matched healthy adults were recruited from local communities. The Falls Efficacy Scale International was used to evaluate FOF. We compared temporal events between healthy and LV groups. For the healthy group, GI under normal vision was further compared to conditions using a low-vision sight simulator (SS) and an immersive virtual reality (VR) environment designed to simulate a fear-evoking experience. Independent <i>t</i>-test and one-way repeated measure ANOVA were conducted for statistical analysis (<i>p</i> < 0.05). <b>Results:</b> People with LV showed a significantly greater FOF than healthy individuals (<i>p</i> < 0.05). During GI, participants with LV exhibited significantly prolonged anticipatory postural adjustment (APA) durations compared to healthy normal and SS conditions (<i>p</i> < 0.05). While VR-evoked fear in healthy participants primarily prolonged the push-off (PO) phase, the delay in the LV group was characterized by a significantly extended initial anticipation (AP) phase. Notably, the APA duration in the LV group showed no significant difference compared to the healthy VR condition, indicating that the inherent fear in LV produces postural delays as severe as those induced by extreme VR-evoked fear of heights (<i>p</i> > 0.05). <b>Conclusions:</b> This study demonstrates that individuals with LV adopt a chronically conservative motor program during the transition from standing to walking. These postural hesitations are statistically comparable to those observed under fear-evoking, VR-induced environments. These findings suggest that LV is associated with a distinct biomechanical strategy that prioritizes static stability over dynamic movement. Accordingly, multidisciplinary rehabilitation approaches that emphasize sensory reweighting, including vestibular training, alongside interventions targeting FOF, may be essential for mitigating altered postural control and reducing fall risk in the LV population.