Robot Assisted Gait Training With Active Leg Exoskeleton (ALEX)

TLDR

Gait training of stroke survivors is crucial to facilitate neuromuscular plasticity needed for improvements in functional walking ability. Robot assisted gait training (RAGT) was developed for stroke survivors using the active leg exoskeleton (ALEX) and a force‑field controller that applies assist‑as‑needed forces at the ankle via actuators on the hip and knee, resisting undesirable motion and providing assistance toward desired motion during a 15‑session study with two participants. By the end of training, patients’ gait patterns improved toward healthy norms, with larger step size, increased knee and ankle excursions, and higher treadmill walking speeds.

Abstract

Gait training of stroke survivors is crucial to facilitate neuromuscular plasticity needed for improvements in functional walking ability. Robot assisted gait training (RAGT) was developed for stroke survivors using active leg exoskeleton (ALEX) and a force-field controller, which uses assist-as-needed paradigm for rehabilitation. In this paradigm undesirable gait motion is resisted and assistance is provided towards desired motion. The force-field controller achieves this paradigm by effectively applying forces at the ankle of the subject through actuators on the hip and knee joints. Two stroke survivors participated in a 15-session gait training study each with ALEX. The results show that by the end of the training the gait pattern of the patients improved and became closer to a healthy subject's gait pattern. Improvement is seen as an increase in the size of the patients' gait pattern, increased knee and ankle joint excursions and increase in their walking speeds on the treadmill.