Table 1 Definitions of the 14 foot dimensions selected in the study

Lengths

1. Foot length (FL): The distance along the foot axis (X-direction) between the Pte and the tip of the longest toe (Rogati et al., 2021; Witana et al., 2006)

2. Ball of foot length (BFL): Length from Pte to the MT measured parallel to the foot axis (Saghazadeh et al., 2015)

3. Outside ball of foot length (OBFL): Length from Pte to the MF measured parallel to the foot axis (Saghazadeh et al., 2015)

Widths

4. Foot width diagonal (FWD): The straight linear distance from the MT and MF projections to the ground for the ball cross-section (Lee et al., 2014)

5. Foot width horizontal (FWH): The horizontal distance (Y-direction) between MT to MF (Lee et al., 2014)

6. Heel width (HW): The width of the heel at 16% of FL forward from the Pte (Lee et al., 2014)

Girths

7. Ball girth (BG): Circumference of the foot, along the medial margin of the head of the 1st metatarsal bone, top of the 1st metatarsal bone, and the lateral margin of the head of the 5th metatarsal bone (Shariff et al., 2019; Witana et al., 2006)

8. Instep girth (IG): Smallest girth over middle cuneiform prominence, i.e., the length of the instep curve (Saghazadeh et al., 2015; Witana et al., 2006)

9. Short heel girth (SHG): Minimum girth around the rear heel point and dorsal foot surface (Xiong et al., 2010)

Heights

10. Instep height (IH): Instep height at 50% total FL is considered the best approximation of dorsal medial longitudinal arch height, representing the dorsal aspect of the medial cuneiform

11. Navicular height (NH): The height of AP, i.e., the prominent navicular bone measured from the standing surface (Hill et al., 2017)

12. Toe height (TH): Vertical height measured from the surface of the footbed to the top of the distal interphalangeal joint of Toe 1 (big toe) (Wan et al., 2017)

Toe angles

13. Toe 1 angle (T1A): Angle between toe 1 angle baseline and the line that passes through the most medial point of the 1st metatarsal head and the most medial point of the big toe measured on the horizontal plane (Lee, 2021)

14. Toe 5 angle (T5A): Angle between toe 5 angle baseline and the line that passes through the most lateral point of the 5th metatarsal head and the most lateral point of the small toe measured on the horizontal plane (Hsieh et al., 2022)