Activation timing patterns of the abdominal and leg muscles during the sit-to-stand movement in individuals with chronic hemiparetic stroke

[Purpose] The purpose of this study was to determine the activation timing patterns of abdominal and leg muscles during the sit-to-stand movement in individuals with chronic hemiparetic stroke. [Subjects] Twenty adults with chronic hemiparetic stroke participated in this study. [Methods] Subjects performed five sit-to-stand movements at a self-selected velocity without using their hands. Surface electromyography was used to measure the reaction time of the bilateral transverse abdominis/internal oblique, rectus femoris, and tibialis anterior muscles during the sit-to-stand movement. [Results] There were significant differences in the reaction time between the affected and unaffected sides of the abdominal and leg muscles. Muscles on the unaffected side had faster reaction time than those on the affected side. Activation of the transverse abdominis/internal oblique muscles was delayed relative to activation of the tibialis anterior muscle during the sit-to-stand movement. [Conclusion] Our findings provide information that may aid clinicians in the examination and management of paretic muscles for transfers in individuals with chronic hemiparetic stroke.