This backrest is mainly for the sauna room special backrest, but it can also be used on the sofa. Backrest can better allow the human body to maintain a more correct sitting posture, the human body in normal life need to naturally bend or sit straight waist, both of which will make the muscles and ligaments around the lumbar spine tension, sedentary easy to lead to soft tissue tension around the lumbar spine. The elasticity and endurance of the muscles and ligaments of the lower back are poor
