The hand is one of the finest and dense organs in human organs. It consists of 27 bones, accounting for 1/4 of the total number of human bones, and the muscle、 blood vessels and nerve distribution and organization are extremely alarming complex, only the tip of the capillary per square centimeter length of up to several meters, Thousands of thousands. These fine neural networks allow us to feel cold, hot, and pain in a few microseconds, and even feel the slightest vibration of the hair. From the date of birth, the hand did not stop the activities, to the end