500 Section - Innovative Comparative Analysis of Customized Medial Forefoot Wedge and Arch Support Insoles on Functional Gait Optimization and Fatigue Reduction in Adults with Flatfoot

A repeated-measures within-subject design recruited 15 adults with flatfoot (aged 22.6±3.1 years). Prior to testing, participants underwent X-ray imaging, 3D foot scanning, and plantar pressure analysis for inclusion confirmation. Each completed treadmill walking and fatigue trials wearing medial forefoot wedge insoles, arch support insoles, and normal insoles, in randomized order with rest between sessions to minimize carryover effects. Data collected included lower limb joint kinematics and kinetics via 3D motion capture, synchronized GRF from force plates, and lower limb muscle EMG patterns to evaluate activation and fatigue. Analyses employed repeated-measures ANOVA and paired t-tests to compare insole conditions.

Results: Both functional insoles improved gait biomechanics compared with normal insoles, notably reducing excessive hip adduction and enhancing knee and ankle joint function. The medial forefoot wedge demonstrated more stable EMG patterns, reduced muscle load, and better coordination under fatigue conditions, sustaining gait stability in the stance phase. Arch support insoles also improved biomechanical parameters, particularly knee and ankle joint moments, but were less effective in maintaining coordination post-fatigue. GRF differences among insoles were minimal during the stance phase, suggesting improvements were mainly biomechanical rather than force-related.

Conclusion:

Customized functional insoles improve lower limb biomechanics and reduce fatigue effects in adults with flatfoot, with the medial forefoot wedge offering superior stability and coordination under fatigue. These findings support personalized insole prescriptions to enhance gait efficiency, reduce muscle load, and potentially lower injury risk, while highlighting the need for larger and longer-term studies to confirm benefits.