A Mobile Cable-Tensioning Platform to Improve Crouch Gait in Children With Cerebral Palsy

Abstract

Gait impairment represented by crouch gait is the main cause of decreases in the quality of lives of children with cerebral palsy. Various robotic rehabilitation interventions have been used to improve gait abnormalities in the sagittal plane of children with cerebral palsy, such as excessive flexion in the hip and knee joints, yet in few studies have postural improvements in the coronal plane been observed. The aim of this study was to design and validate a gait rehabilitation system using a new cable-driven mechanism applying assist in the coronal plane. We developed a mobile cable-tensioning platform that can control the magnitude and direction of the tension vector applied at the knee joints during treadmill walking, while minimizing the inertia of the worn part of the device for less obstructing the natural movement of the lower limbs. To validate the effectiveness of the proposed system, three different treadmill walking conditions were performed by four children with cerebral palsy. The experimental results showed that the system reduced hip adduction angle by an average of 4.57 ± 1.79° compared to unassisted walking. Importantly, we also observed improvements of hip joint kinematics in the sagittal plane, indicating that crouch gait can be improved by postural correction in the coronal plane. The device also improved anterior and lateral pelvic tilts during treadmill walking. The proposed cable-tensioningplatform can be used as a rehabilitation system for crouch gait, and more specifically, for correcting gait posture with minimal disturbance to the voluntary movement.