The effect of foot position on erector spinae and gluteus maximus muscle activation during sit-to-stand performed by chronic stroke patients

[Purpose] The aim of this study was to use surface electromyography (EMG) to investigatethe effects of different foot positioning on bilateral erector spinae (ES) and gluteusmaximus (GM) activation during sit-to-stand performed by individuals with stroke.[Subjects] Fifteen randomly selected participants with stroke were enrolled in this study.[Methods] All the participants were asked to perform sit-to-stand (STS) using threedifferent strategies: (1) symmetric foot position, (2) unaffected foot placed behind theaffected foot position (asymmetric-1), (3) affected foot placed behind the unaffected footposition (asymmetric-2). An EMG system was used to measure ES and GM muscle activities.The strategies were performed in a random order, and the mean values of five measurementswere used in the analysis. One-way repeated measure ANOVA was used to determine thestatistical significance of differences between the conditions. [Results] The affected ESmuscle activity was significantly greater in asymmetric-2 (180.7±73.4) than in symmetricalfoot placement (149.8±54.2). In addition, the affected ES, unaffected ES, and affected GMmuscle activity were significantly greater in asymmetric-2 (180.7±73.4, 173.5±83.1,98.3±90.3 respectively) than in asymmetric-1 foot placement (147.3±53.8, 151.2±76.5,84.9±73.8 respectively). [Conclusion] Our results suggest that it may be more desirablefor persons with stroke to place the affected foot behind the unaffected foot whenperforming STS to increase affected ES and GM muscle activation.Key words: Electromyography, Sit-to-stand, Stroke