Differences in kinetic and kinematic factors when choosing the leg for gait initiation after stroke: An analysis using the Xcom dynamic balance index

Abstract

[Purpose] The purpose of this study was to analyze the differences of the kinetic and kinematic factors when choosing the leg for gait initiation after stroke from the viewpoint of dynamic stability. [Subjects] Fifteen stroke patients. [Methods] Subjects performed gait initiation (GI) starting with either leg. GI was measured using a 3D motion analysis system and force plates. The difference in kinetic and kinematic data, which is duration, displacement of center of mass, center of pressure (COP), extrapolated center of mass (Xcom), the relationship between the time integral of the COP displacement and the amount of forward COM momentum, and joint moment between the two tasks was compared using the paired t-test. [Results] When the unaffected leg was used as the first swing leg, a smaller mediolateral sway and larger forward sway of Xcom was found, and the time integral of the COP displacement and the amount of forward COM momentum were correlated. [Conclusion] It is more stable for stroke patients to start walking with the affected leg than the unaffected leg, though it is not as efficient.