Correlations among trunk impairment, functional performance, and muscle activity during forward reaching tasks in patients with chronic stroke

[Purpose] This study aimed to investigate the relationships among trunk impairment, functional performance, and muscle activity during forward reaching tasks in patients with chronic stroke. [Subjects and Methods] Twenty-three chronic stroke patients participated in this study. Trunk impairment and functional performance were evaluated using the Trunk Impairment Scale, Berg Balance Scale, Timed Up and Go Test, and 10-Meter Walk Test. All subjects were asked to perform 3 different forward reaching tasks (affected side reaching, forward reaching, and less-affected side reaching), and measurements were taken during these 3 tasks by using surface electromyography. Correlation analyses were performed to assess the relationships among trunk impairment, functional performance, and muscle activity during the forward reaching tasks. [Results] Spearman's correlation analysis revealed a strong, significant correlation between the Trunk Impairment Scale and functional performance, that was associated with balance and gait ability. During the 3 different forward reaching tasks, muscle activities of the less-affected lower extremity were significantly correlated with functional performance. [Conclusion] This study revealed the correlations among trunk impairment, functional performance, and muscle activity during forward reaching tasks in patients with chronic stroke and emphasized the importance of trunk rehabilitation.