The modulating role of foot morphology on the effects of acute fatigue on ankle proprioception and spatial perception

Background Foot morphology may influence sensorimotor control under fatiguing conditions. However, the combined effects of acute fatigue on proprioception and perceptual components across different foot structures remain unclear.Objective How does acute fatigue affect ankle proprioception, distance perception, and action-specific perception in individuals with flatfoot, pes cavus, and normal foot arches?Methods Ninety participants (30 per group: flatfoot (FF), pes cavus (PC), and normal (N); 15 males and 15 females each) completed the study. Foot posture was classified using the Staheli Arch Index. Ankle joint position sense (active repositioning of dorsiflexion, plantarflexion, inversion, and eversion), distance perception (blindfolded walking toward an 8-meter target), and action-specific perception (static distance estimation) were assessed before and after a 10-minute treadmill run at 80% of estimated VO₂max. Data were analyzed using one-way ANOVA and ANCOVA with pre-test scores as covariates.Results Following fatigue, the flatfoot group exhibited significantly greater dorsiflexion proprioceptive errors than the normal group (p = 0.024), while both flatfoot and pes cavus groups showed significantly greater plantarflexion errors than the normal group (p < 0.05), with no significant differences between the two deformity groups. Fatigue impaired distance perception in the pes cavus and normal groups, but not in the flatfoot group. No significant changes were observed for action-specific perception across groups. Flatfoot and pes cavus are associated with heightened vulnerability to fatigue-induced proprioceptive degradation, particularly in the sagittal plane.Conclusions These findings underscore the role of foot structure in sensorimotor resilience and have implications for injury prevention and rehabilitation in individuals with foot deformities.