Changes in foot structure, particularly the presence of flatfeet, have been associated with various limitations in physical performance. This study aimed to investigate the relationship between flexible flatfeet and functional movement, balance, agility, and core muscle strength in young females. Ninety-six female students between the ages of 18 and 25 voluntarily participated in this study. The
... [Show full abstract] navicular drop test was used to evaluate the longitudinal arch of the foot. The participants were classified into flexible flatfeet (n = 25) and normal feet (n = 71) groups. Fundamental movement evaluated by the functional movement screening test (FMS); static balance using the Sharpened-Romberg test; dynamic balance using Y-test; agility and coordination using 4 × 9-m shuttle run; endurance of the abdominal muscles and lumbar spine extensor muscles using respectively Partial curl-up and maintaining the plank position, were evaluated. The results of the independent t-test and Mann–Whitney U test showed a significant difference between the two groups in functional movement, abdominal muscle endurance, static balance and lumbar extensor muscle endurance variables (p ≤ 0.05). In the normal feet group, a significant correlation was found between functional movements with abdominal muscle endurance, dynamic balance and agility. The results of this study indicate that individuals with flexible flatfeet exhibited significant impairments in functional movement, core muscle strength, and balance compared to those with normal foot arches. These findings highlight the importance of early identification and appropriate interventions for individuals with flexible flatfeet to mitigate potential negative consequences on physical performance and overall health.