The present invention relates to a chair enclosing balls that stimulate the proprioceptive sensory system and the tactile sensory system of the person sitting in it. The balls provide a sporadic pressure on the body and are mutually displaceable, whereas the chair is shaped to the body of the person sitting in it. If the person seated in the chair changes position, the balls will displace again and provide a different sporadic pressure on the body. These stimuli give an increased feeling of the body and its boundary, whereby a calming effect is achieved. The balls can have a diameter in the range of 10mm to 100mm.
