Effects of Foot Type and Ankle Joint Fatigue Levels on the Trajectories of COP and COM during a Single-Leg Stance

Abstract

The purpose of this study was to investigate the effects of foot type and ankle joint fatigue levels on the trajectories of center of pressure and center of mass during a single-leg stance. The study subjects included 24 healthy women (normal foot group, n=10; pronated foot group, n=14). Ankle joint muscle fatigue was induced by using an isokinetic dynamometer, where the fatigue levels were measured on plantar flexion and dorsiflexion at angular velocities of 30°/s at 50% and 30% of the peak torque of ankle plantar flexion. Following assessments in the anteroposterior direction according to the level of fatigue, the pronated foot group showed decreased single-leg stance ability at 50% and 30% of the fatigue level. Moreover, the normal foot group showed better singleleg stance ability than the pronated foot group at 30% of the fatigue level. Following assessments in the mediolateral direction, we noted that the single-leg stance ability did not differ significantly according to the levels of fatigue or foot type. In conclusion, ankle plantar flexion at 50% and 30% of the peak torque reduced the ability of the pronated foot group to achieve a single leg stance in the anteroposterior direction. Moreover, the normal foot group showed better single-leg stance ability than the pronated foot group.

Effects of Skill Level and Feet Width on Kinematic and Kinetic Variables during Jump Rope Single Under

“…Indeed, width during dynamic walking is slightly decreased in an effort to secure dynamic stability and propulsion. Furthermore, improving static stability by widening the base of support results in an increase in width during a static standing posture (Shin, Youm, & Son, 2013). In the jump rope of this study, the preferred width was found to decrease by approximately 32~37% and the induced width decreased by 82~85%.…”