PURPOSE This study analyzed the relationship between the center of pressure (CoP) trajectory area and ankle inversion/eversion movement across different walking speeds and established a new assessment method for predicting ankle instability. METHODS Twenty-seven healthy young adult males (20 yrs) performed treadmill walking trials at three speeds (slow, normal, and fast). Their cumulative CoP trajectory area and ankle inversion/eversion angles were analyzed, with particular focus on the third quadrant area (3QA). RESULTS During slow walking, mediolateral CoP range (p < .05) and 3QA (p < .05) increased significantly compared to normal and fast walking. Concurrently, ankle inversion/eversion angle (p < .05) and range of motion (p < .05) also increased. Furthermore, 3QA exhibited significant negative correlations with maximum ankle eversion angle (p = .001) and eversion angular velocity (p = .005). CONCLUSIONS This study provides findings that the CoP trajectory’s cumulative area, specifically 3QA, serves as a critical predictor of ankle joint eversion kinematics. These findings have potential implications for ankle instability assessment, prevention, footwear design, and rehabilitation protocols.
PURPOSE The purpose of this study was to provide information for improving the performance and skills of 500 m speed skaters by analyzing the kinematic and kinetic changes in their slide board movements over time. METHODS The subjects were 10 male short-distance skaters in their 20s to 30s who were registered as professional athletes with the Korea Sports Council. The changes in joint angle, joint moment, and joint power over time in the subjects’ slide board motion were measured and analyzed. RESULTS It was found that during phase 2 of the skater’s slide board movement, there was an increase in plantar flexion and a decrease in flexion of the lower extremity joint and extension of the knee and hip joint, with decrease in positive power of the knee joint. CONCLUSIONS The results of this study are expected to provide practical information to skating coaches and athletes by quantifying the biomechanical factors observed over time during slide board movements. In addition, this study is expected to contribute to the field of speed skating by presenting scientific training methods and proposing new analysis techniques to improve performance in the future.
