**2.2. Our previous study 1**

Vibration stimulation on a skeletal muscle of healthy adults is known to bring on effects such as reflexivity contraction of an agonist muscle by muscle spindle Ia afferent nerve excitability, and inhibition of the antagonist muscle, called "tonic vibration reflex". Vibration stimulation also causes inhibition of monosynaptic reflexes such as the tendon reflex and stretch reflex while stimulation with vibration continues. These effects vary depending on stimulus conditions.
