The effects of gait speed on plantar pressure variables in individuals with normal foot posture and flatfoot

Purpose: It is not known how gait speed affects plantar pressure characteristics in flatfoot. The aim of this work was to investigate the effects of gait speed on plantar pressure variables in flatfoot by comparing it to normal foot posture. Methods: Thirty individuals with flatfoot and 30 individuals with normal foot posture were recruited. Plantar pressure variables were obtained by a pressure-sensitive mat at self-selected slow, normal, and fast speeds. All assessments were performed on the dominant foot, and three satisfactory steps were obtained for each gait speed condition. The order of gait speeds was randomized. Results: In the flatfoot group, the contact area was higher in the midfoot, third metatarsal, and hallux at all speeds, also in the second metatarsal at slow and normal speeds than the normal foot posture group ( p < 0.05). The maximum force was higher in the midfoot and hallux at all speeds in the flatfoot group ( p < 0.05). Also, the maximum force was lower in the first metatarsal at normal and fast speeds, and in the lateral heel at fast speed ( p < 0.05). In the flatfoot group, the peak pressure was found to be higher in the hallux at slow speed, but to be lower in the first metatarsal at fast speed ( p < 0.05). Further, plantar pressure distribution was affected by gait speed in both feet. Conclusions: Analysis of plantar pressure variables should be performed at different gait speeds.