Massage heads in devices typically move in two directions – up, down, and sideways. In devices with 3D massage, the heads also move in a third direction, specifically forwards and backwards. This allows them to extend further from the backrest, thus massaging the muscles more intensely. The user can therefore adjust not only the area and type of massage, but also its depth and strength. This movement better mimics the pressure of a real masseur's hands, who can press more or, conversely, less intensely.
