Effects of a Short Foot Exercise Program with and without Reactive Neuromuscular Training on Ankle Kinematics and Kinetics in Adolescents with Flexible Flatfoot

Background Flexible flatfoot (FFF) is a prevalent musculoskeletal condition in adolescents and is associated with altered ankle–foot kinematics, impaired shock absorption, and increased risk of lower-extremity injuries. Short Foot Exercises (SFE) have been shown to enhance intrinsic foot muscle function; however, the biomechanical effects of combining SFE with Reactive Neuromuscular Training (RNT) have not been sufficiently investigated. Methods This single-blinded, three-arm randomized controlled trial (RCT) included 48 adolescent girls (12–15 years) with clinically diagnosed FFF. Participants were randomly assigned to an SFE group, an SFE combined with RNT (SF + RNT) group, or a control group. The intervention lasted eight weeks with three supervised sessions per week. Ankle kinematics were assessed using a three-dimensional motion capture system, and kinetic and center of pressure (COP) variables were collected using a force plate during barefoot walking. Outcome measures included ankle range of motion (ROM), moment dorsiflexion (DF), vertical ground reaction force (GRF) peak, loading rate, and frontal-plane ankle motion. Data were analyzed using mixed-design ANOVA with post hoc comparisons. Results Significant time × group interactions were found for moment DF, ankle DF, plantarflexion, inversion, and eversion (p < 0.05). The SF + RNT group demonstrated the most pronounced improvements, including increased ankle DF and inversion, reduced eversion and plantarflexion, and a greater reduction in moment DF compared with the control group. Loading rate decreased significantly over time in both intervention groups (p < 0.001), whereas Peak GRF showed no significant group or interaction effects. Conclusions An eight-week SFE program improved ankle kinematic and kinetic parameters in adolescents with FFF, with superior outcomes observed when combined with RNT. This combined approach may enhance neuromuscular control, optimize gait biomechanics, and reduce injury risk in this population. Trial Registration: IRCT20250610066157N1 on 2025 / 07 / 04.