Research Information System
Musculoskeletal Science and Practice, vol.78, 2025 (SCI-Expanded)
Background: People with flatfoot were reported to exhibit poorer standing postural stability than those with normal foot posture (NF). However, whether postural stability is altered during dynamic tasks including sit-to-stand transition, step-up/down, and walking along a line in people with flatfoot is not clarified. Objectives: To compare postural stability during static standing and dynamic tasks between young adults with flatfoot and NF. Design: A case-control study. Method: Twenty-five people with flexible flatfoot and twenty-five people with NF were included. Postural stability was assessed using the NeuroCom Balance Master. Sway velocity values (deg/sec) during bipedal and unipedal standing with eyes-open and eyes-closed were obtained. The weight transfer time (sec), rising index (% body weight), and sway velocity (deg/sec) parameters of the sit-to-stand test, the speed (cm/sec) and end sway (deg/sec) parameters of the tandem walk test, and the lift-up index (% body weight), movement time (sec), and impact index (% body weight) parameters of the step-up-over test were obtained. Results: Standing postural stability was poorer in the flatfoot group with a moderate effect size (p < 0.05, Cohen's d = 0.66). The speed during tandem walking and left and right lift-up forces were lower in the flatfoot group with large effect sizes (p < 0.05, Cohen's d = 1.33, 1.01, and 0.97, respectively). Conclusions: The flatfoot group exhibited poorer static and dynamic postural stability, with larger effects observed in dynamic conditions. Possible lower concentric muscle strength of the lower extremity warrants further investigation.