Fig. 5

a Example EMG profiles of the anterior deltoid muscles in different tasks during upwards motion. These profiles show that the anterior deltoid muscle of the non-paretic arm was activated in almost the same way across the four different types of bimanual motion, while the corresponding muscle of the paretic arm was activated in different ways depending on the type of bimanual motion. b Statistical analysis of the variability of muscle activities on the non-paretic and paretic arms across all patients’ trials. There was significantly higher dispersion for muscle activation of the paretic arms. The bars represent means, with whiskers representing \(\pm \hbox {SD}\)