Abstract
Flatfeet are a common condition associated with altered foot biomechanics, leading to potential functional limitations and increased risk of musculoskeletal injuries. This condition disrupts the kinetic chain, impacting proximal segments such as the core and hips, which are crucial for maintaining stability, balance, and agility. While various interventions have been explored, the role of generalized lower-extremity strengthening programs, such as calisthenics, in addressing these functional deficits is not well-established. This study investigated the impact of a 16-week calisthenics program on functional movement, core strength, balance, and agility in female university students with and without flexible flatfeet. We aimed to assess whether this generalized strengthening intervention could improve these key performance metrics and whether the relationship between Functional Movement Screen (FMS) scores and other functional measures differed between the two groups. The study also explored the correlation between FMS scores and other measures of performance in these two distinct groups. A total of 96 female university students (25 with flexible flatfeet, 71 with normal feet) participated in a 16-week calisthenics program. Assessments included FMS, core strength (partial curl-up, plank), balance (Sharpened Romberg, Y-balance test), and agility (4 × 9-m shuttle run). Statistical analyses included non-parametric tests to assess within-group changes and between-group differences, as well as correlation and regression analyses to explore the relationship between FMS scores and performance variables. Both groups showed significant improvements in FMS scores, core strength, balance, and agility following the intervention. In the normal feet group, FMS scores correlated positively with core strength, static balance, and dynamic balance; conversely, these correlations were not observed in the flexible flatfeet group, suggesting a potential influence of altered biomechanics on the relationship between FMS and performance. While a generalized calisthenics-based training program yields significant improvements in functional movement capabilities, core stabilization, equilibrium, and rapid directional changes in both cohorts, the association between FMS metrics and other performance variables differed in individuals presenting with flexible flatfeet. This variation suggests that functional movement in this population is modulated by factors beyond those typically assessed by FMS, potentially due to the unique biomechanical adaptations induced by flatfeet. Therefore, a deeper understanding of the physiological responses to generalized training in individuals with flatfeet is imperative for the creation of targeted interventions to enhance movement efficiency and performance results. The lack of correlation in this group suggests that further research is needed before generalizing these findings to a broader population. Clinical Trials Registration IRCT20130109012078N8: Registered 2023-02-03, Iranian Registry of Clinical Trials (IRCT); IRCT20130109012078N7: Registered 2023-01-19, Iranian Registry of Clinical Trials (IRCT).