Differences in kinetics and kinematics of sit-to-stand between independent and dependent post-stroke individuals.

Background: The sit-to-stand movement is important for the rehabilitation of individuals with poststroke hemiplegia. This study aimed to clarify the variation in kinetic and kinematic characteristics of sit-to-stand movements according to differences in the ability of individuals with poststroke hemiplegia.

Methods: Twenty five individuals in the subacute phase of stroke-induced hemiplegia, who needed assistance to practice the sit-to-stand movement (dependent group) and 25 individuals in the subacute phase of stroke-induced hemiplegia who could stand up independently (independent group) were selected for the study. To ensure a fair comparison, the two groups were matched for age, sex, body size, and the paretic side. The sit-to-stand movement was quantified using a three-dimensional motion-analysis system, and the resulting kinetics, kinematics of thorax, pelvis and lower limb, and weight bearing were compared.

Findings: The dependent group exhibited significantly reduced hip flexion torque and significantly greater thoracic and pelvic anterior tilt prior to seat-off than the independent group. After seat-off, the dependent group exhibited significantly reduced paretic knee extension torque and significantly greater weight bearing on the nonparetic side, along with significantly elevated hip extension torque on the paretic and non-paretic sides, in comparison to the independent group.

Interpretation: The kinetic and kinematic characteristics of the sit-to-stand maneuver before seat-off in the dependent group poststroke differ from those in the independent poststroke individuals, as previously reported. These findings also suggest that weight-bearing on the non- paretic side is key in the sit-to-stand movement of dependent individuals.