How to measure the firmness of a mattress?

How to call soft and hard moderate? The simplest measurement method is: lie on your back and stretch your hand inward to see if there is a gap between the three obvious bends of the neck, waist, buttocks and thighs; Then turn over to one side and try the same method to see if there is a gap between the concave part of the body curve and the mattress. If not, it proves that the mattress is closely consistent with the natural curve of the neck, back, waist, hips and legs during sleep. Such a mattress can be said to be moderately soft and hard. Everyone has different preferences for the soft and hard mattresses. Some people like to sleep in hard beds, while others like to sleep in soft beds. What hardness mattresses are good mattresses? Thirty years ago, there was a discussion in Germany about whether a hard mattress or a soft mattress was good. That discussion attracted the participation of the German Bachelor of ergonomics and led to the study of human sleep posture. The result of the study is that both hard and soft mattresses are harmful to human health and sleep, and the correct mattress should be a high elastic mattress. In other words, when the force applied to the mattress is large, the mattress should fall much more and produce more support to the human body, and vice versa. This is because the human body is a curve. Only on a high elastic mattress can the human body and back be supported, especially the waist should have strong support, so that all parts of the human body can relax and have a full rest. Due to the shallow S-shape of the human spine, a support with appropriate hardness is required when lying down. Therefore, an elastic mattress is very important to the comfort of the human body and the quality of sleep. Choose a mattress can not simply rely on self feeling, too soft or too hard is not appropriate, but according to the difference between height and weight. Light weight people sleep in a soft bed, so that their shoulders and hips fall into the mattress slightly, and their waist is fully supported. Heavy weight people are suitable for sleeping on a hard mattress. The strength of the spring can give each part of the body proper, especially whether the neck and waist are well supported. You can refer to the height, weight and mattress soft and hard comparison table, which will be more scientific.