Characterizing Heart Rate Variability on Gait Biomechanics in Children with Cerebral Palsy During Lokomat Gait Rehabilitation

Robot-assisted gait training (RAGT) has been shown to improve the locomotor ability in patients with neurological gait disorders by implementing automated, repetitive, and task-specific gait training. Although RAGT is typically designed for a long-term training that requires cardiovascular endurance, how RAGT affects heart rate variabilities (HRV) remains unclear. The main purpose of the present study is to monitor the HRV throughout a single-session RAGT for children with cerebral palsy and similar neurological movement disorders. Six patients participated in a 20-minute-long RAGT session during which their HRV was measured as we varied the body weight support (BWS) and the guidance force (GF). Results showed that the mean RR while walking on the treadmill with the robotic exoskeleton was significantly lower and remained steady as the conditions progressed compared to the metric during overground walking before and after the RAGT session. By contrast, the HRV quantified by the root-mean-squared standard deviation (RMSSD) did not show a significant difference when compared to the resting state HRV. Additionally, the SD2/SD1 ratio in Poincare plots showed a tendency to temporarily change depending on the training parameters, i.e., with lower BWS and GF. Altogether, the results indicate that the changes in the sympathetic nervous system (SNS) during the RAGT session are not significantly different from the resting state. The results support that RAGT may serve as a long-term rehabilitation program for children with neurological conditions such as cerebral palsy.