The leg-swing interface: a novel approach to seated VR locomotion with balanced immersion and physical load

Locomotion in Virtual Reality (VR) is a key factor in determining user immersion and comfort. Thus, various locomotion methods in VR while seated have been explored. While controller-based seated locomotion is widely used due to its simplicity and low physical effort, it often lacks embodied motion cues, reducing immersion. On the other hand, seated walking-in-place (WIP) techniques enhance immersion through body-based interaction but can introduce significant physical fatigue. In this paper, we propose Leg-swing, a novel foot-based seated VR locomotion interface designed to balance immersion and physical load. Users swing their legs forward and backward to move through virtual environments, mimicking the rhythm of walking without high physical load. The system uses a high-resolution pressure sensor embedded in the seat to infer locomotion speed and leaning angle without the need for wearable sensors. Through a user study comparing Leg-swing to joystick and seated WIP that utilize marching motions, we found that Leg-swing was perceived to provide significantly higher immersion than joystick-based locomotion with similar physical effort, and users reported significantly lower physical load than seated WIP while maintaining comparable perceived immersion. These results suggest that Leg-swing offers a promising middle ground between immersion and physical load for seated VR locomotion.