Generating Faster Kinesthetic Reaction by Inter-personally Connecting Muscles

Instantaneously generating own body movements in response to the movement of others, such as establishing defensive posture in sports and learning kick-out timing from therapists in gait rehabilitation, is an essential aspect of interpersonal exercises and contact sports. However, ignition of movement based on a visual stimulus requires approximately 250 milliseconds (ms), which is too late for certain interpersonal physical interactions that require immediate reaction.

Thus, we introduce “Wired Muscle,” a system that connects muscle activities between two persons using electromyogram (EMG) measurement and electrical muscle stimulation (EMS) to generate responsive movement that are faster than those generated by the visual information-based process. Our system detects the muscle activity of a person by the EMG and triggers the EMS to drive the muscle of the other person to induce corresponding counter movements. In a pilot study using our system, the reaction time to the motion of another person could be shortened to approximately 60 ms. In addition, some participants perceive that the kinesthetic reaction was performed by their own will even though the muscle movement was electrically driven by prior stimuli. We envision that our system will enable direct connection of kinesthetic experiences among multiple persons and will form the basis for a novel paradigm of motor learning.

Collaboration with Dr. Shunichi Kasahara, a researcher at Sony Computer Science Laboratories.


Daisuke Tajima, Jun Nishida, Pedro Lopes, Shunichi Kasahara; Successful Outcomes in a Stroop Test Modulate the Sense of Agency When the Human Response and the Preemptive Response Actuated by Electrical Muscle Stimulation are Aligned. Journal of Vision 2020 (PDF)

Jun Nishida, Shunichi Kasahara, and Pedro Lopes. 2019. Demonstrating Preemptive Reaction: Accelerating Human Reaction using Electrical Muscle Stimulation Without Compromising Agency. ACM SIGGRAPH 2019 Emerging Technologies (PDF) (Laval Virtual Grand Prize)

Shunichi Kasahara, Jun Nishida, and Pedro Lopes. 2019. Preemptive Action: Accelerating Human Reaction using Electrical Muscle Stimulation Without Compromising Agency. ACM CHI 2019 (PDF)

Jun Nishida, Shunichi Kasahara, Kenji Suzuki. Wired muscle: generating faster kinesthetic reaction by inter-personally connecting muscles. ACM SIGGRAPH 2017 Emerging Technologies (PDF)