Background & Objectives: The significant increase in musculoskeletal disorders in children necessitates the conduct of more extensive research and the strengthening of preventive and care strategies. The foot is one of the most important and vulnerable parts of the lower extremity. Due to its bony, ligamentous, and muscular structures, it plays a vital role in weight–bearing, shock absorption, balance maintenance, and force transmission to the ground. Flexible flatfoot is a structural and functional deformity characterized by a combination of static and dynamic abnormalities, and it is among the most common lower–limb disorders in children and adolescents. This condition is associated with sensorimotor alterations and functional impairments. The increasing prevalence of musculoskeletal disorders in children underscores the need for more comprehensive research and the development of effective preventive and therapeutic strategies. In this context, therapeutic exercise, as an active and sustainable approach, holds a high priority in the management of flexible flatfoot by addressing the underlying causes of the deformity and improving long–term functional performance. This study aimed to examine whether incorporating reactive neuromuscular training (RNT) into a foot core exercise program could improve proprioception, ankle range of motion (ROM), arch indices, and pain levels.

Methods: The present study was a single–blind randomized clinical trial with a pretest–posttest design including two experimental groups and one control group. The statistical population consisted of 12–15–year–old female students with flexible flat feet in Alborz Province, Iran. The sample size was determined using G*Power software with an effect size of 0.40, a statistical power of 0.80, and an alpha level of 0.05. Considering a 20% attrition rate, the final sample size was calculated as 48 participants. Using random sampling, 48 volunteer participants who met the study inclusion criteria were recruited. They were then randomly assigned to three groups (n=16 per group): a core foot exercise group, a combined core foot and reactive neuromuscular training group, and a control group. The inclusion criteria were as follows: female students aged 12–15 years with flexible flat feet; a navicular drop greater than 10 mm (positive Navicular Drop Test) (Brody, 1982); confirmation by a specialist physician; completion of a written informed consent form; and voluntary participation in the study. The exclusion criteria included absence from more than three training sessions, lower–extremity injury during the study, and unwillingness to continue participation. The interventions were delivered for 8 weeks, with three sessions per week (40–70 min per session). Proprioception was assessed using an isokinetic dynamometer (PRJP), ankle dorsiflexion/plantarflexion ROM via goniometry, Staheli and Chippaux–Smirak indices through footprint analysis, and pain intensity at rest using the Visual Analog Scale (VAS). Data were analyzed using SPSS software (version 27) in two stages: descriptive and inferential statistics. Descriptive statistics included the calculation of means and standard deviations. Inferential statistics were performed using analysis of covariance (ANCOVA) and Bonferroni post hoc tests. Statistical significance was set at p < 0.05.

Results: The results showed that, after controlling for pre–test scores, significant differences were observed between the intervention and control groups at post–test in the Staheli Index (p < 0.001), Chippaux–Smirak Index (p < 0.001), dorsiflexion range of motion (p = 0.035), inversion proprioception (p = 0.008), and eversion proprioception (p = 0.013). However, no significant differences were found between the intervention and control groups in plantarflexion range of motion (p = 0.050) and pain (p = 0.279).

Conclusion: Based on the findings of the present study, reactive neuromuscular training combined with core foot exercises improves dorsiflexion range of motion, proprioception, and footprint indices. Therefore, the clinical application of a combined approach involving core foot exercises and reactive neuromuscular training is recommended for the rehabilitation and correction of children with flat feet.