Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation.
Results:The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p< 0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.