[Study on "Hegu (LI 4) regulates face and mouth" based on palmomental reflex]

To explore the correlation between hand and face-mouth, so as to provide nerve reflex basis for the theory "Hegu (LI 4) regulates face and mouth".

Seven hundred and sixty-three participants who met the inclusive criteria were divided into different age groups. The skin around participants' thenar eminence was gently scraped to be observed whether there was an involuntary movement around the face or mouth, which was palmomental reflex. The results of palmomental reflex were recorded.

The total occurrence rate of palmomental reflex was 46.26%. For those who were 0 to 1 years old, the palmomental reflex was all positive; for those who were 21 to 36 years old, the positive rate was 20.45%, which was the lowest; for those who were 65 to 85 years old, more than half of them were positive. The majority of those who were 0 to 2 years old were bilateral positive palmomental reflex, while the majority of those who were 65 to 85 years old were unilateral positive palmomental reflex.

There is a certain connection between hand and face-mouth. The occurrence rate of palmomental reflex changes from high to low over age increasing, and then changes from low to high with the aging, presenting a "high-low-high" U-shaped curve, which is possible related to the growth and recession of nervous system.