Age- and sex-based clustering of foot dimensions in northwest Iran

Ethnicity and sex influence foot dimensions, essential for ergonomic footwear to reduce injury. This study analyzes Azeri men and women in Iran’s northwestern region; 4,297 subjects’ feet aged 20–60 were scanned; 3,122 healthy feet were selected. Twenty-nine foot anthropometric dimensions were computed via Python (2021). Principal component analysis (PCA) using SPSS (26) reduced these to three principal components (PCs) explaining most variance in foot shape. K-means clustering was applied across eight age subgroups (AG 1 –AG 8 ) and the total group (AG T ), with clustering quality assessed using the Davies–Bouldin index. Key findings revealed significant sex-related differences in foot dimensions ( p < 0.00). Regarding age-related differences, significant variations were observed in length, girth, and height dimensions for women (p-values: 0.00–0.03), while for men, only length showed significant age-related changes ( p = 0.00). In the total group, PC1–PC3 represented length, width/girth, and height in men, and girth, length, and height in women, respectively. Cluster analysis classified feet into small, medium, and large categories, with medium size being the most common across all age subgroups except AG3. Forefoot shape analysis revealed that men predominantly exhibited Egyptian, Semi-Roman, and Greek types, while women primarily showed Egyptian and Semi-Roman types, with the Egyptian type being the most frequent in both sexes. These findings support age- and sex-specific footwear design, especially for foot length in men and girth in women, and provide a quantitative basis for region-specific manufacturing, potentially improving foot health and offering economic benefits for local producers.