The scientific truth is very simple, that is, people lie on their side, sleep on their stomach, and lie flat at the junction of mouth and throat. There is some truth in this sentence. Some people like to sleep on their stomach, some people like to lie flat, and some people like to lie on their side. Sleeping positions are different, but there are good and bad. That is, the posterior pharyngeal wall, when sleeping on your back, it is easy to block the airway and suffocate. If you sleep too hard, you will lie down.
The ancients gave it three different meanings. The ancients thought that sleep was not only sleep, but also a deeper realm, which led to the influence of sleeping posture on people. Without any precautions, you are most vulnerable to the attack with your limbs open. Of course, this seems to be an animal.
Bend your legs slightly. In this way, the heart is in a high position, not oppressed, and the liver is in a low position, which is beneficial to metabolism. Digestion and absorption are better. Of course, it is inseparable from a good schedule, a good sleeping environment and a suitable sleeping position. So what did the ancients mean by "crouching tiger, hidden dragon, crouching tiger, hidden dragon"? In ancient times, people walked like the wind, sat like a clock, stood like a pine, and lay like a bow. In other words, a formal posture instrument is necessary for a person. As for the essence of sleeping like a bow, it is very beneficial to human health. It can relax the muscles of the whole body, which is very beneficial to visceral blood circulation.
It means like a dragon, energetic and alert. People who can sleep like this all the time have high alertness and strong mobility, so they use dragons as metaphors.