Effects of sensorimotor training combined with short foot exercise on knee and ankle gait kinematics in individuals with flatfoot

Abstract

Background: Flatfoot, a common condition characterized by medial longitudinal arch collapse, alters foot and lower-limb mechanics. Sensorimotor training and short-foot exercises can improve postural stability and functional performance. However, their combined effects on gait kinematics remain unclear. This preliminary study evaluated the 6-week effects of combining these interventions on knee and ankle gait kinematics in individuals with flexible flatfeet. Methods: Thirty-two asymptomatic young adults with flexible flatfoot (14 males, 18 females; navicular drop ≥ 10 mm) were randomly assigned to an experimental group (sensorimotor training combined with short-foot exercises; n = 16) or a control group (sensorimotor training only; n = 16) using sealed opaque envelopes. Training was conducted 3 times per week for 6 weeks in a motion laboratory. Gait kinematics were assessed pre- and post-intervention using the VICON motion system. Outcomes included peak ankle inversion, eversion, dorsiflexion, and plantarflexion angles, knee internal and external rotation angles, and range of motion (ROM) in the sagittal, frontal, and transverse planes. Two-way repeated-measures analysis of variance was used for the analysis. The partial eta squared (ηp2) was reported as the effect size. Results: Baseline demographics (age, sex, and body mass index) were similar between groups (P > .05). Significant group × time interactions were observed for gait variables. The experimental group showed a significant increase in peak ankle inversion (95% confidence interval (CI): 0.53–2.71; P = .004; ηp2 = 0.244) and a decrease in peak eversion (95% CI: 1.68–4.89; P = .002; ηp2 = 0.279). Peak knee internal rotation significantly decreased (95% CI: −9.92 to −2.82; P = .006; ηp2 = 0.228). Reductions were also observed in sagittal plane ankle ROM (95% CI: −4.88 to −0.68; P = .001; ηp2 = 0.317) and transverse plane knee ROM (95% CI: −7.75 to −4.01; P = .003; ηp2 = 0.254). No significant changes were found in ankle dorsiflexion, plantarflexion, knee external rotation, or frontal plane ankle ROM (P = .088, .126, .766, .136, respectively; ηp2 = 0.003–0.094). Conclusion: Combined sensorimotor and short-foot training more effectively improved gait kinematics than sensorimotor training alone, suggesting a promising non-surgical approach for managing flatfoot.