The sudden stirring of the legs at night is mainly considered for two reasons: the first reason is that the muscles of the legs continue to contract for too long due to overexertion during the day, resulting in excessive anaerobic metabolism and accumulation of metabolites. During sleep at night, the muscles are stimulated by metabolites and changes in the internal environment around the muscles, resulting in spasmodic twitching, which leads to limb movement. The second cause is seen in the presence of leg compression due to incorrect sleep posture, which affects local blood circulation and also results in increased anaerobic metabolism of local muscles, a signal that is transmitted to the brain via local receptors. However, the brain is in a relatively inhibited state during sleep, and the brain’s control and inhibition of the anterior horn of the spinal cord is not as strong as during the daytime. When the brain sends out signals for limb movement, the inhibitory effect on the anterior horn of the spinal cord becomes weaker, and when the anterior horn of the spinal cord sends out commands for muscle movement, the amplitude of the activity often becomes larger and less precise, and the muscle twitches are very violent, resulting in the phenomenon of relatively strong stirring.