Foot shape analysis of professional American Football players

The goal of this paper is to quantify the shape of National Football League (NFL) players' feet and to identify foot shape characteristics that facilitate the development and refinement of position-specific footwear for NFL players. Statistical shape analysis was performed on three-dimensional (3 D) scans of 290 NFL players' feet obtained from 4 NFL teams during preseason training camps to identify the principal components that explain characteristics of the shape variability. Eight foot shape measurements were then defined to reflect the main principal components and were quantified. The foot volume, the arch shape in conjunction with the foot length, and the foot curvature explained more than 80% of the foot shape variation. The average foot length was 293 +/- 13.7mm and width was 110.6 +/- 6.8 mm. Significant differences were observed between position groupings, primarily with regard to size. The prevalence of flat feet (defined as 0 arch depth) was greater in linemen and hybrid position groups than in the skill group. This information can facilitate improvements in the lasts used to create shoes for elite-level players and can also help inform footwear selection.