A Perturbation-based Gait Training with Multidirectional Waist-Pulls Generalizes to Split-Belt Treadmill Slips

Abstract

Gait disorders and subsequent falls are major causes of chronic disability. Most falls occur during walking when an individual fails to recover from a loss of balance. We have developed an innovative cable-driven robot that delivers unpredictable waist-pull perturbations while walking on a treadmill. In previous experiments, we showed that a training session with repeated waist-pulls induces acute motor adaptations in gait and balance recovery reactions. To date, it is unknown if the effects can be transferred to different types of external balance perturbations. This study aims to investigate if the exposure to repeated waist-pulls can improve the recovery reactions to slips. Fourteen healthy young adults were assigned to either an Experimental (EG) or a Control Group (CG). The EG was trained with multidirectional waist-pull perturbations of various intensities. The CG walked for a comparable amount of time on the treadmill with cables on, but without experiencing any waist-pull. Before and after the training, all participants were exposed to three slip-like perturbations by suddenly accelerating one belt of the treadmill in the forward direction. The Margin of Stability (MoS) was evaluated while reacting to the perturbations. At post-training, the EG showed increased stability in reaction to the waist-pull and slip-like perturbations. In contrast, the reaction to slip-like disturbances of the CG remained unchanged. A single session of gait training comprised of repeated waist-pulls showed immediate transfer to split-belt treadmill slips. The findings of this pilot study are encouraging for developing new fall prevention therapies.