Validity of Two-Dimensional Static Footprint in Medial Longitudinal Arch Evaluation and the Characteristics of Athletes' Footprints

BackgroundWe aimed to explore the validity of two-dimensional static footprint analysis in medial longitudinal arch evaluation as well as the characteristics of athletes footprints to provide a basis for the evaluation and selection of athletes. MethodsExperiment One: Twenty-nine high level athletes (runners and jumpers) and forty normal college students were selected. Based on the X-ray photos taken of the medial foot, we measured the calcaneal inclination angle, the calcaneal-first metatarsal angle and the ratio of height to length of the medial longitudinal arch. We collected indicators of two-dimensional static footprints. Experiment Two: 106 high level athletes (runners and jumpers) and 104 normal college students were selected. We also collected indicators of two-dimensional static footprints. ResultsThe average measuring the Interclass Correlation Efficient (ICC) of calcaneal inclination angle, calcaneal-first metatarsal angle, the ratio of height to length of the medial longitudinal arch, the width of ball, arch and heel, the length of footprint and each toe, Chippaux-Smirak Index (CSI) and Staheli Index (SAI) were higher than 0.800. Regardless of athletes or college students, male or female, the correlation between CSI, SAI and calcaneal inclination angle, calcaneal-first metatarsal angle, the ratio of height to length of the medial longitudinal arch was statistically significant (P<0.05). College students CSI of the right foot is significantly higher than that of the left foot regardless of gender (P<0.05). ConclusionsWe prove the qualification of CSI and SAI in medial longitudinal arch evaluation and explain that the relative height of medial longitudinal arch is an important indicator in track and field.