Overground Robot-Assisted Gait Training for Pediatric Cerebral Palsy

Abstract

The untethered exoskeletal robot provides patients with the freest and realistic walking experience by assisting them based on their intended movement. However, few previous studies have reported the effect of robot-assisted gait training (RAGT) using wearable exoskeleton in children with cerebral palsy (CP). This pilot study evaluated the effect of overground RAGT using an untethered torque-assisted exoskeletal wearable robot for children with CP. Three children with bilateral spastic CP were recruited. The robot generates assistive torques according to gait phases automatically detected by force sensors: flexion torque during the swing phase and extension torque during the stance phase at hip and knee joints. The overground RAGT was conducted for 17~20 sessions (60 min per session) in each child. The evaluation was performed without wearing a robot before and after the training to measure (1) the motor functions using the gross motor function measure and the pediatric balance scale and (2) the gait performance using instrumented gait analysis, the 6-min walk test, and oxygen consumption measurement. All three participants showed improvement in gross motor function measure after training. Spatiotemporal parameters of gait analysis improved in participant P1 (9-year-old girl, GMFCS II) and participant P2 (13-year-old boy, GMFCS III). In addition, they walked faster and farther with lower oxygen consumption during the 6-min walk test after the training. Although participant P3 (16-year-old girl, GMFCS IV) needed the continuous help of a therapist for stepping at baseline, she was able to walk with the platform walker independently after the training. Overground RAGT using a torque-assisted exoskeletal wearable robot seems to be promising for improving gross motor function, walking speed, gait endurance, and gait efficiency in children with CP. In addition, it was safe and feasible even for children with severe motor impairment (GMFCS IV).

The Effects of Over-Ground Robot-Assisted Gait Training for Children with Ataxic Cerebral Palsy: A Case Report

“…RAGT with an untethered exoskeleton is an emerging field; thus, only a few trials of RAGT with an untethered exoskeleton have been conducted as case reports or single arm studies, showing improvements in the walking ability, gross motor function, and balance in patients with CP [ 12 , 23 , 24 , 25 ]. In addition, there is a cross-over randomized controlled study showing the changes in gait kinematics and kinetics, which occurred after only 5 min of RAGT with untethered exoskeleton [ 26 ].…”

“…Further study is therefore warranted to address this uncertainty. Both tethered and untethered RAGT have demonstrated some improvements in walking ability, gross motor function, and postural balance [ 12 , 23 , 24 , 25 , 31 , 32 , 33 ]. However, the evidence to support the benefits of both tethered and untethered RAGT for children with CP is still weak.…”

“…To determine the appropriate amount of assistive joint torque, a spring-loaded inverted pendulum model of gait dynamics is used. The ankle joints are not actuated [ 12 ] but are mechanically limited to prevent hyper-dorsi/plantar flexion. The actuator modules consist of brushless direct-current motors (70 W, EC45-C45 a Maxon motor Ltd., Sachseln, Switzerland), customized gear sets, and sensors for measuring the motor angular position and the absolute angle of the human joint.…”

“…Over-ground RAGT was performed for 20 sessions (30 min per session, five sessions per week) as performed in a previous study [ 12 ]. All training was conducted by a physical therapist with over 10 years of experience in CP rehabilitation.…”

“…Angel Legs M (ANGEL ROBOTICS Co., Ltd., Seoul, Korea) is an untethered wearable robot system with actuators in both the hip and knee joints. A previous study reported that the use of this robotic system was feasible and had the potential to enhance the gross motor function and walking capacity of children with spastic CP [ 12 ]. To the best of our knowledge, no study has reported the feasibility and benefits of untethered RAGT for children with ataxic CP.…”