Esports have highlighted both their potential for social inclusion and the accessibility challenges faced by individuals with physical disabilities. This study introduces a novel paradigm for inclusive esports by shifting game control from traditional kinematic inputs to kinetic inputs. An EMG-based control interface enables gameplay through force regulation (e.g., muscle activation and inhibition). The aim is to explore how this interface enables common gameplay mechanics among players with and without physical disabilities. User Study 1 involved 20 able-bodied participants performing competitive esports tasks to examine how EMG-based control accuracy is influenced by movement range, such as wrist and elbow motion. User Study 2 extended the investigation to eight participants with physical disabilities to compare control accuracy between disabled and able-bodied users. The findings suggest that the interface enables common gameplay mechanics for individuals who can separately control activation and inhibition of each muscle corresponding to each EMG sensor via calibration adjustment but disability-related involuntary muscle activity and unintended co-contraction remains a major challenge for the interface.

Wearable electromyography (EMG)-based control interfaces are widely used by various users including both individuals with and without physical disabilities. Since EMG-based control interfaces are unfamiliar to most users and require individually defined input detection thresholds, differences in the sense of agency among users are to be expected. This study aimed to investigate individual trends in the sense of agency when operating an unfamiliar EMG-based control interface. To this end, we utilized a task that combines the intentional binding (IB) measurement paradigm with a perceptual-motor learning task to measure task performance and implicit sense of agency during EMG operation. To classify individual trends in the sense of agency, we conducted clustering based on variations in raw IB data. We found that cluster with large variations in IB had a low implicit sense of agency, reflecting the difficulty of the interface operation in detecting muscle movements as input. In addition, an analysis of the cluster with low variability in IB suggests that participants who took longer to become familiar with the input operation exhibited higher implicit agency, while those who found the task easy exhibited lower implicit agency. These findings suggest that IB may serve as a useful measure for capturing differences in operability not reflected in task performance or explicit reports of sense of agency.

In postural control, the light touch effect stabilizes posture by adding sensory cues when a part of the body, such as the fingertips, lightly touches a support surface. However, maintaining light touch can be difficult depending on individual characteristics and task difficulty. To address this challenge, we previously proposed a system that utilizes electrical muscle stimulation (EMS) on the index finger extensor muscle to maintain light touch. The present study aims to investigate the immediate after-effects of sustained light touch through the EMS-based system on postural control. Participants performed an eyes-closed single-leg stance without touch in the pre- and post-tests and performed the same task with their index finger lightly touching a handrail between the two tests (LT-test). During the LT test, the EMS group (n=10) lightly touched the handrail while EMS was administered, and the control group (n=10) performed the light touch without EMS. The postural sway parameters and electromyography were compared within each group between pre- and post-tests. The results showed a significant difference in the center of pressure sway in the EMS group, indicating decreased postural sway immediately after the LT test. This suggests that the sustained light touch with EMS enabled users to perceive more detailed sensory cues and facilitated the subsequent retention of postural control. Moreover, the postural stability was strongly associated with pelvic stability.