Bradykinesia in Parkinson's disease (PD) reduces walking speed, shortens stride length, and causes irregular gait due to impaired muscle control. Although soft exosuits can improve walking performance in PD patients, it remains unclear whether optimal assistance body segments and torque levels vary depending on patients' conditions and symptoms. This study examined gait parameter changes in three PD patients at different Hoehn and Yahr stages when a soft exosuit assisted either hip extension or flexion. To find the suitable assistance torque for each patient, torque levels were progressively increased at each segment. Furthermore, to evaluate only the effects of bradykinesia, experiments were conducted in conditions without freezing of gait. We assessed bradykinesia primarily through changes in stride length and gait velocity. Our findings showed variability in response: two patients demonstrated greater improvement with hip extension assistance compared to flexion assistance, while the opposite result occurred for the remaining patient. This highlights that selecting the appropriate assistance segment significantly impacts gait performance in PD patients. Therefore, personalized assistance strategies tailored to individual conditions are crucial. Future studies should involve recruiting more homogeneous patient groups for each assistance condition to better understand the mechanisms behind the effectiveness. These findings will aid in developing wearable robot technologies to support daily walking in PD patients.