EMSWalker: Integrating Gait-Synchronized Electrical Muscle Stimulation for Seated Walking-in-Place in Virtual Reality

Abstract

Locomotion methods in virtual reality (VR) that simulate walking, such as walking-in-place and foot tapping, provide necessary tactile feedback for a coherent walking experience. Nevertheless, such methods could benefit from providing muscular sensations for realistic virtual walking across various terrains. We present EMSWalker, a system that provides proprioceptive feedback during seated walking-in-place through gait cycle-synchronized electrical muscle stimulation (EMS). EMSWalker stimulates major leg muscles in sync with gait cycle patterns, transforming foot tapping sensations into virtual walking experiences across level, uphill, and downhill terrain. Through three user studies, we (1) investigate EMSWalker’s effects on users’ proprioceptive drift and embodiment in a walking context, (2) evaluate users’ ability to discriminate EMS patterns corresponding to terrain slopes, and (3) examine EMSWalker’s impact on users’ virtual walking experience. Results demonstrated proprioceptive drift induction, discriminable terrain-specific stimulation patterns, and enhanced presence in VR, confirming EMSWalker’s ability to enable realistic and spatially immersive virtual walking.