Effects of the lower visual field obstruction on adaptive gait during obstacle crossing in healthy young adults

Obstacle navigation represents a critical challenge in daily locomotion, with failed balance recovery during crossing frequently leading to falls. This study investigated the effects of lower visual field obstruction on adaptive gait during obstacle crossing in healthy young adults using a novel "box-carrying obstruction method."

Fifteen male participants (age, 20.9 ± 1.3 years; height, 178.6 ± 5.0 cm; weight, 71.7 ± 7.5 kg; leg length, 91.7 ± 5.1 cm) walked with or without a box (30 × 30 × 25 cm or 30 × 30 × 35 cm) while crossing obstacles at heights of 10, 20, and 30% of leg length in randomized order. Measured gait parameters included step length, step width, step velocity, penultimate foot placement (PFP), toe distance (TD), heel distance (HD), and lead/trail limb vertical toe clearance (LTC/TTC). Statistical analyses included repeated-measures ANOVA and Pearson correlations.

No significant interactions between LVF obstruction and obstacle height were observed (all P > 0.05). Obstacle height significantly reduced step velocity (P = 0.002), while LVF obstruction independently affected TD (P < 0.001), HD (P < 0.001), LTC (P < 0.001), and TTC (P < 0.001). Negative correlations were found between TD and HD (r = -0.46; P < 0.001), and positive correlations between LTC and TTC (r = 0.60; P < 0.001).

LVF Obstruction had a broader impact on spatial gait adjustments than obstacle height, with step velocity serving as the primary adaptive strategy for higher obstacles. The strong coupling between lead and trail limb clearances suggests interlimb coordination, highlighting the role of shared sensorimotor information in obstacle negotiation.