SITAG SPRING-MOTION means that the chair adapts to every movement its user makes. This relieves pressure on the pelvis and on the hips when sitting for a long time. This system is combined with SITAG FLOW-TECH: the extremely elastic backrest takes the effects of pressure and adapts to the rotations of the back and upper body. Just sink into the SITAGWAVE, it will do the rest and adapt to you. Not the other way around.