Journal of Clinical Physiotherapy Research

Background: Flexible flatfoot is linked to changes in lower-limb alignment and increased dynamic knee valgus (DKV), which may predispose individuals to musculoskeletal disorders. Limited evidence exists comparing corrective exercises and custom foot orthoses on foot alignment and knee kinematics. Methods: Thirty male adolescents (12–15 years) with flexible flatfoot were randomly assigned to three groups: a combined comprehensive exercise program with custom-made orthoses, custom orthoses only, or a control group. Interventions lasted 6 weeks. Outcome measures included navicular drop, medial longitudinal arch angle, rearfoot eversion, and 3D lower-limb kinematic variables during a single-leg step down task. MANCOVA was used with baseline adjustments (p ≤ 0.05). Results: A significant multivariate group effect was observed (Wilks’ Λ = .000, F (14, 28) = 476.67, p < .001, partial η² = .996). The combined intervention group showed greater improvements across all foot alignment variables and DKV kinematics compared to orthoses-only and control groups. Effect sizes were large (0.14 < η²), and all changes exceeded MCID values. Conclusion: Combining a comprehensive exercise program with customized foot orthoses results in greater improvements in foot alignment and DKV kinematics than orthoses alone. This approach addresses both distal and proximal aspects of the kinetic chain and may benefit adolescents with flexible flatfoot. Long-term follow-up studies are recommended.