Characteristics of foot alignment in high school soccer players with chronic ankle instability.

Study design: Cross-sectional studyObjective: To clarify the characteristics of foot alignment by CAI in high school soccer players and the relationship between foot alignment and CAITBackground: There is no consensus on foot alignment in CAI, and the relationship with severity is unclearMethod and setting: 63 high school soccer club members were divided into a CAI group (n=30) and a control group (n=33), and foot alignment was measured using the Navicular Drop Test (NDT), Weight Bearing Lunge Test (WBLT), calcaneal angle, and Leg Heel Angle (LHA). The difference in foot alignment between the CAI group and the healthy group was examined by t-test, and multiple regression analysis was used to extract factors related to CAIT.Results: Statistically significant differences were observed between the CAI group and the control group in the NDT, WBLT, calcaneal angle, and LHA (p<0.001). In a multiple regression analysis with CAIT as the dependent variable, single-leg LHA (β=1.48, p<0.001) and NDT (β=-0.78, p<0.001) were extracted for the entire group (n=63). Furthermore, multiple regression analysis was performed on the two items of single-leg LHA and NDT extracted for the entire group of 63 participants for the CAI group and the control group, and NDT (β=-0.60, p<0.01) was extracted for the CAI group. No items were extracted for the control group.Conclusion: CAI by high school soccer players was shown to have foot valgus alignment compared to the control group. Furthermore, there was a statistically significant difference between CAIT and NDT, suggesting that the more severe the CAI, the lower the medial longitudinal arch.