Foot Arch Index in Different Age Groups: A Clinical Anatomical Study

Background: The medial longitudinal arch of the foot plays a vital role in weight distribution and locomotion. The Foot Arch Index (FAI) provides a reliable measure of arch morphology across populations. Understanding age-related variations in FAI is important for clinical assessment and management of foot disorders. Material and Methods: This cross-sectional observational study included 240 participants stratified into three groups: Group I (6–15 years), Group II (16–40 years), and Group III (41–65 years), with 80 individuals in each. Footprints were obtained using the inked footprint method under full weight-bearing. The FAI was calculated as the ratio of the area of the middle third of the footprint to the total footprint area, excluding the toes. Arch types were classified as high (<0.21), normal (0.21–0.26), or flat (>0.26). Statistical analysis was performed using one-way ANOVA with p < 0.05 considered significant. Results: Children in Group I demonstrated the highest mean FAI (0.28 ± 0.05), while young adults in Group II exhibited the lowest values (0.24 ± 0.04), indicating better developed arches. Middle-to-older adults (Group III) showed intermediate values (0.26 ± 0.05). The differences among groups were statistically significant (p < 0.001). Distribution analysis revealed that flat arches were most common in children (62.5%), normal arches predominated in young adults (55.0%), and older adults showed a mixed pattern with nearly equal proportions of flat (47.5%) and normal arches (41.3%). High arches were relatively uncommon across all groups, with the highest prevalence observed in young adults (17.5%). Conclusion: The study demonstrates that foot arch morphology evolves with age, showing flattening in children, maturation in young adults, and partial decline in older adults. These findings highlight the importance of age-specific evaluation of foot arch in clinical and anatomical assessments