Lying flat and leaning forward, because of the large curvature of the lumbar spine, the waist will be significantly higher than the bed surface and even exceed the palm when lying flat. At this time, the lower pressure of lumbar and thoracic intervertebral discs increases and the upper pressure decreases.
If we are going to use a thin pillow on the bed ourselves, we can sleep our knees under this pillow in supine position, and we can adjust the balance of the joints so that the waist is as close to the bed as possible and restore natural bending.
When the pelvis leans backward, the lower ends of the lumbar and thoracic vertebrae bend and straighten. When lying down, the waist will be closer to the bed surface, and there may even be no gap at all. The height of pubic symphysis will be significantly higher than that of anterior superior iliac spine, lumbar vertebra and intervertebral disc at the lower end of thoracic vertebra. The pressure above will increase and the pressure below will decrease.
At this time, putting the pillow below the waist can also achieve the purpose of keeping the lumbar spine as natural as possible. However, if the pillow is uncomfortable, there is no need to use it.
? In the side life, some people like to lie on their side and go out with one foot. When the pelvis leans forward, put the pillow between your knees or under your protruding knees. If you don't use a pillow, the hip joint will be higher than the knee joint when you lie on your side, which will easily cause lumbar rotation and further protrusion.
When the pelvis leans backward, consider whether to use a pillow according to your own comfort.
It is worth reminding that no matter whether the pelvis leans forward or backward, the pillow lying on the side can protect our knees when we sleep.
In addition, some people may be used to sleeping on their stomachs. This posture is not recommended, but if you really like sleeping on your stomach for a while, you'd better put a pillow under your stomach, which will help improve the alignment of your spine and reduce the pressure on your intervertebral disc.
To sum up, I believe you already know how pillows protect your waist and knees. Welcome everyone to leave a message in the comments section.