Control of ankle joint motion change induced by vibration stimulation on the Gastrocnemius muscle during continuous joint motion

It has been shown that changes in movement caused by reflex phenomena and kinesthetic illusion can be induced by giving vibratory stimulation on specific muscles during limb movements. By using this phenomenon, there is a possibility that the lower-limb perception-assist, in which inappropriate motion is automatically modified, is realized. In this study, change of ankle joint motion by giving the vibration stimulation on the gastrocnemius muscle in the lower-limb is studied by performing the experiment of adding vibration stimulation to the gastrocnemius muscle during the movement of ankle joint dorsiflexion and plantar flexion under several frequency ranges. The results indicate that the amount of motion change varies depending on the frequency of the vibration stimulation. Based on the characteristics of motion change with respect to vibration stimulation, a method to control the change of the user's ankle joint dorsiflexion motion by adjusting the frequency of the vibration stimulation to achieve the target motion, which is different from the user's intended motion, is evaluated. It is confirmed that there is a possibility that the vibration stimulation can be applicable to modify the human ankle joint motion for the perception-assist using frequency change.