Seated gait training with arm swing synchronized to a walking virtual avatar.

In older adults, although gait training using a VR avatar has recently garnered attention, standing implementations entail safety risks and high operational costs. Therefore, we aimed to establish a safe and feasible gait training approach by leveraging rhythm assistance from a VR avatar in a seated posture, and to examine its acute effects on gait performance as a proof-of-concept. We developed a multimodal audiovisual feedback system that presents a walking VR avatar synchronized in real time with the participant's arm swing, and conducted seated gait training for twelve healthy older adults aged 70 years or older. Two training conditions were implemented: an "Avatar" condition, in which the avatar was presented, and a "No Avatar" condition, in which it was not. Gait was measured before and after each training condition to evaluate gait performance. The experimental results showed that in the Avatar condition, participants' arm swing movements were synchronized with the walking movements of the VR avatar. Regarding gait performance, stride length and maximum foot clearance significantly increased under the Avatar condition, with stride length showing a significantly greater improvement compared to the No Avatar condition. These findings suggest that synchronized audiovisual rhythm assistance provided by a VR avatar can contribute to enhancing the spatial characteristics of gait, even during seated training.