Objectives: This study investigated the associations between gait velocity and kinematic variables in the first half of the gait cycle according to stroke severity. We performed gait analysis in individuals with stroke, focusing on changes in the center-of-gravity (COG) position on the paretic side in the first half of stance phase.Methods: Gait data of 80 individuals (20 each in Brunnstrom recovery stage: III, IV, V and VI) with stroke acquired using a 3D motion analysis system was retrospectively analyzed. Associations of gait velocity with the COG positions in the anteroposterior directions and vertical increases in the first half of stance phase on the paretic side were compared according to stroke severity, using correlation analysis.Results: Gait velocity showed strong positive correlations with step length on the paretic side at initial contact, the rate of vertical increase in the COG during single-leg stance, and the proportion of single-leg stance time in the gait cycle. The associations between velocity and each kinematic variable differed according to stroke severity. Gait velocity was strongly correlated with the rate of vertical increase in the COG during single-leg stance and the proportion of single-leg stance in severe hemiplegia, while a strong correlation was observed with step length on the paretic side in mild hemiplegia.Conclusion: An upward shift of the COG during single-leg stance was an important factor in gait velocity, and the correlation between gait velocity and the rate of vertical increase in the COG during single-leg stance was stronger when hemiplegia was more severe.

Objects：Sit-to-stand (STS) interventions are frequently used as part of stroke rehabilitation. This study aimed to clarify the kinematic and kinetic characteristics of patients recovering from stroke, who have difficulties with STS movement.Method：The participants included 26 stroke patients who struggled to complete the STS maneuver. Using a 3D motion analysis system, the kinematic and kinetic parameters during STS were retrospectively analyzed and compared between failed and successful trials. The kinematic parameters of the trunk and lower limbs were obtained within the seat-off phases, and the kinetic indices of the lower limbs were obtained from measurements taken before and after the seat-off phase. The weight-bearing ratio on the unaffected side was calculated from the vertical ground reaction forces.Results：In the successful trials, analyses of the parameters revealed more forward tilting of the pelvic and thoracic regions, a further forward and downward shift of the center of mass, and larger hip and knee extension moments than those of the failed trials. However, there was no difference in the weight-bearing ratio on the non-paralyzed side.Conclusion：This study revealed that the kinematic and kinetic properties of the STS maneuver differed between successful and failed trials among patients with stroke. The study therefore provides useful information for clinical evaluation and rehabilitation.

Objects：Sit-to-stand (STS) interventions are frequently used as part of stroke rehabilitation. This study aimed to clarify the kinematic and kinetic characteristics of patients recovering from stroke, who have difficulties with STS movement.Method：The participants included 26 stroke patients who struggled to complete the STS maneuver. Using a 3D motion analysis system, the kinematic and kinetic parameters during STS were retrospectively analyzed and compared between failed and successful trials. The kinematic parameters of the trunk and lower limbs were obtained within the seat-off phases, and the kinetic indices of the lower limbs were obtained from measurements taken before and after the seat-off phase. The weight-bearing ratio on the unaffected side was calculated from the vertical ground reaction forces.Results：In the successful trials, analyses of the parameters revealed more forward tilting of the pelvic and thoracic regions, a further forward and downward shift of the center of mass, and larger hip and knee extension moments than those of the failed trials. However, there was no difference in the weight-bearing ratio on the non-paralyzed side.Conclusion：This study revealed that the kinematic and kinetic properties of the STS maneuver differed between successful and failed trials among patients with stroke. The study therefore provides useful information for clinical evaluation and rehabilitation.