Rehabilitation program
The participants performed 10 sessions of gait training (5 times per week) each lasting 30 ± 5 min session per day. One or two physical therapists accompanied each participant during gait training. For group A, the therapists operated the device and prevented falls, but they did not give any advice on gait to the participants. The participants also received a combination of physical (except gait training), occupational, or speech therapy rehabilitation. The maximum rehabilitation time including gait training was 3 h/day in both groups.We set synchronization gain, gait cycle, and joint angles as the assist conditions of the device. Among these, synchronization gain was fixed to 0.1 at the hip joint and 0.3 at the knee joint throughout the rehabilitation period in all participants. The gait cycle and joint angles varied from individual to individual, and they were set according to the gait parameters of the fastest gait performance on days 0 and 7. The amplitude of the joint angle was set at 140% at the unaffected hip joint and 110% at the unaffected knee joint, and the gait cycle was set at 85%. Therefore, the assist conditions were set 40% wider hip joint, 10% wider at the knee joint, and 15% faster in the gait cycle than the gait parameters of the fastest gait performance. The conditions set on day 0 were used for gait training on days 1–6, and those updated on day 7 were utilized on days 8–13. These parameters meant that the amount of assistance provided by the robot was larger at the hip joint than at the knee joint, i.e., the device-in-charge robotic support was more influential at the hip joint than at the knee joint. With these assist conditions, the device enabled the participants to reproduce their best gait performance faithfully during gait training.