Abstract: A device for controlling the reflex response of a muscle or muscular group articulating a living body joint by applying a specific mechanical stimulation (SMS) to the external area of the joint which corresponds to the mechano-receptors guiding a natural reflex of the muscle or muscular group. The embodiments of the device include a support member adapted to be mounted to the wrist ankle or lumbar spine joint, a pressure-applying member and a resilient portion interposed between the support member and the pressure-applying member to continuously apply a required pressure intensity during articulation movements of the joint. The mechano-receptors include skin mechano-receptors and deeper joint mechano-receptors. The reflex response of muscles articulating a joint is facilitated by a low external SMS pressure intensity and inhibited by a high external SMS pressure intensity.