Effect of motor imagery training on symmetrical use of knee extensors during sit-to-stand and stand-to-sit tasks in post-stroke hemiparesis

Abstract

To investigate the effect of motor imagery training (MIT) on the symmetrical use of knee extensors during sit-to-stand and stand-to-sit tasks. We measured the electromyographic (EMG) data in the knee extensor on the affected side of 3 volunteers with post-stroke hemiparesis. We used a single-subject multiple-baseline research design across individuals. The EMG data were collected from knee extensors while performing the sit-to-stand and stand-to-sit tasks. The EMG activation and onset time ratios for the knee extensors were calculated by dividing the EMG activation and onset time of knee extensor action on the affected side by these on the unaffected side. MIT consisted of a 10-min detailed description of 5 stages: preparation, sit-to-stand tasks, weight shifting during standing, stand-to-sit tasks, and completion. During MIT, the EMG activation ratios of participants 1, 2, and 3 increased by 11.24%, 18.07%, and 26.91%, respectively, in the sit-to-stand task and by 12.11%, 14.31%, and 25.92%, respectively, in the stand-to-sit task. During MIT, the onset time of participants 1, 2, and 3 decreased by 36.09%, 24.27%, and 25.61%, respectively, in the sit-to-stand task and by 26.81%, 27.20%, and 22.83%, respectively, for the stand-to-sit task. These findings suggest that MIT has a positive effect on the symmetrical use of knee extensors during sit-to-stand and stand-to-sit tasks.