Determinants and predictors of the maximum walking speed during computer-assisted gait training in hemiparetic stroke patients

Abstract

Objective: To investigate biomechanical determinants and predictors of walking speed in early gait training after stroke. Design: Prospective. Setting: Physical therapy room of Tohoku University Hospital. Participants: Thirty-four male hemiparetic stroke patients received 8 weeks of computer-assisted gait training (CAGT), which was initiated within approximately 3 months after stroke onset. Main Outcome Measurements: The time and the number of steps required to walk 10m at the fastest possible speed (maximum walking speed [Mws]), the sway path of the center of feet pressure (CFP) in the upright posture, the change in CFP when shifting the body weight either left to right or back and forth, and the maximal isokinetic muscle strength during extension of both knees were measured at the start and at 4 and 8 weeks. Stepwise regression procedures were performed to analyze determinants and predictors of the MWS using the MWS as the dependent variable and personal characteristics, standing balance, and the muscle strength of both knees as the independent variables. Results: The MWS significantly increased from 40.4 to 76.5m/min on average after 8 weeks. The determinant of MWS at the start was the postural control of shifting to the left and right (coefficient of determination of 45.4%). The determinant of MWS at 4 and 8 weeks was the muscle strength during knee extension on the affected side (coefficient of determination of 62.9% and 54.5%, respectively). The predictors of MWS at 4 weeks were the MWS at the start of CAGT, followed by muscle strength during knee extension on the affected side and the time from stroke onset to the start of CAGT (total variance of 84.3%). The predictors at 8 weeks were the MWS at the start, followed by the muscle strength during knee extension on the affected side (total variance of 73.4%). Conclusions: After 4 weeks, the biomechanical determinant of MWS had changed from the postural control of weight-shifting from left to right to the muscle strength during knee extension on the affected side. The MWS at 4 and 8 weeks could be predicted by the initial MWS, the initial muscle strength during knee extension on the affected side, and the time since stroke onset, with high coefficients of determination.