The effect of Clarke’s angle variability on the static and dynamic balance of different sports

Abstract

Background: Flatfoot affects postural control by altering the biomechanics of the lower limb, sensory input, and proprioception. Poor static and dynamic balance can influence the physical performance of competitive sports athletes and increase the risk of lower limb injury. Footprint analysis using Clarke’s angle (CA) is easy to perform and has good diagnostic performance as an alternative flatfoot assessment for a large athlete population. Our study aims to determine the effect of CA variability on the static and dynamic balance of different sports using the one-leg stance (OLS) and star excursion balance test (SEBT). Methods: This is an analytic observational study with a retrospective cohort design. Medical record data from 209 athletes’ feet from 11 sports were collected to determine the subjects’ characteristics and research variables. Curve estimation and regression tests were performed to assess the effect of CA variability on the OLS and normalized reach distance of SEBT (NSEBT). Results: The mean CA of all athletes was 44.82±11.14o. The mean time of OLS of all athletes was 47.78±40.54 seconds. The least and the farthest average normalized reach distance was done in the anterolateral direction (79.06±11.88 %) and posterior direction (93.45±18.98 %). There is no effect of CA variability on the OLS of all sports, male and female athletes. There is an effect of CA variability on the OLS of Wushu athletes, also on the NSEBT of whole athletes (lateral, posterolateral, posterior, posteromedial directions; male athletes (posterolateral direction); female athletes (anteromedial direction); and different sports, includes athletic (anterolateral, lateral, posterolateral, posterior, posteromedial, medial, anteromedial direction); fencing (anterolateral direction); and running (anterolateral, lateral, posterior, posteromedial, medial, anteromedial, composite directions). Conclusion: Clarke’s angle variability significantly affects the static balance of Wushu athletes and the dynamic balance of athletes in athletics, fencing, and running.