Changes in muscle activation and ground reaction force of the lower limbs according to foot placement during sit-to-stand training in stroke patients

Objective: The aims of the study were to investigate the kinetic effects of sit-to-stand training in various foot positions on the coronal plane in patients with strokes and to suggest appropriate exercises. Design: Thirty-six poststroke subjects participated in this study. The subjects performed three sit-to-stand trials in the following foot positions: (a) symmetric foot positioning (symmetric), (b) affected foot placed to the side (asymmetric 1), and (c) and less affected foot placed to the side (asymmetric 2). They were asked to perform sit-to-stand training at a spontaneous velocity and remain standing for 5 secs, whereas the vertical ground reaction force was measured using force platforms. The activation of lower limb muscles was evaluated using surface electromyography, and the peak and mean vertical ground reaction force and weight-bearing symmetry ratio were evaluated using force platforms. Results: Our results showed significant increases in the muscle activation, peak and mean vertical ground reaction force, and weightbearing symmetry ratio of the lower limbs using the asymmetric 2 strategy (P < 0.05). Conclusions: Our results suggest that sit-to-stand training with the less affected foot placed to the side by the width of the subject’s foot may be the most beneficial in the rehabilitation of patients with hemiparetic stroke.