We investigated optimal vibrating conditions for inducing illusory elbow extension movement to develop various practical applications. The experimental factors were the vibration frequency (30, 50, and 70 Hz), vibration amplitude (three phases for each frequency condition), and contact press force (3, 5, 7, 9 N). We subjectively assessed the presence or absence of an illusion, and the vividness on a five-point scale. The results of this study showed that when the vibration amplitude and contact press force became higher than certain values at vibration frequencies of 50 or 70 Hz, the illusion was produced for 80% or more participants, and the vividness of the illusion was increased. Under these stimulation conditions, illusory elbow extension movement can be easily produced; we can develop an interface device that will only provide kinesthetic sensations without the actual motion. Such an interface device can be used for rehabilitation and education fields, and gaming devices.
