The changes of muscle activity by robot-assisted gait training methods in children with brain injury: a pilot test

Research Objectives: Robot-assisted gait training effectively improves gait functions through high-intensity, high-repetition training. However, research on training methods that can heighten clinical effects while considering the characteristics of robots has not been conducted extensively.

Design: The aim of this study is to examine the changes in exercise intensity and muscle activity for different training parameter values of robots when walking robots (Lokomat Pro, Hocoma, Switzerland) are applied to children with brain injury.

Setting: This study was conducted on children who are hospitalized at the National Rehabilitation Center or outpatient.

Participants: Three children with cerebral palsy (Child 1: female, GMFCS Ⅳ; Child 2: male, GMFCS Ⅳ; Child 3: male, GMFCS Ⅲ) participated in this study.

Interventions: Robot-assisted gait training (40 min/session, a total of 20 sessions) was performed for children with gait disturbances caused by brain injury. The speed at which children feel comfortable and the BWS at which body alignment is maintained were fixed. The guidance force (GF) value was decreased by 5% from 100% over 20 sessions to observe the changes in exercise intensity and muscle activity.

Main Outcome Measures: The muscle activity of the lower extremity was measured using surface electromyography equipment (Trigno Wireless EMG, Delsys, U.S.A.), whereas exercise intensity was calculated based on the heart rate using a heart rate measurement device (WristOx2 model 3150, NONIN, U.S.A.).

Results: After training, these children experienced an increase in the muscle activity of both legs as the GF decreased. Furthermore, the average heart rate and the rating of perceived exertion of these children increased with decreasing GF. Child 1, 2 experienced increased gross motor function and decreased muscle tone after training, in which Child 2, 3 experienced improved gait ability.

Conclusions: The clinical effects of robots can be improved by adjusting training parameters. Further studies should be conducted to develop training methods for robots by investigating neurophysiological changes in parameters, such as exercise intensity and muscle activity, with respect to parameter combinations of robots.

Author(s) Disclosures: Sora Park, Eunkyeong Lee, Jihye Jung, Hyunkyung Kim