When the elbow is patted with sand and purple bumps appear, it is due to the arm being subjected to external force stimulation, causing damage to the blood vessels within the skin and the spillage of red blood cells onto the skin surface, resulting in purplish skin. In severe cases, purple bumps may occur. Many people believe that this is caused by the body detoxifying, but this is actually a misunderstanding. Patting the arm is a commonly used massage method in traditional Chinese medicine, which stimulates acupuncture points to detoxify the body.
Why do purple bumps appear when the elbow is patted with sand? When patting the elbow, the veins in the hand are excessively stimulated, causing damage to the vascular endothelial cells and increased permeability. This increased permeability of local blood vessels allows red blood cells to spill out and seep into the skin, leading to subcutaneous blood stasis and the appearance of purplish skin. If the technique is too harsh, the locally purplish skin will rise above the skin surface, forming purple bumps.
Can patting the arm really detoxify? Patting the arm does not actually detoxify. Patting is indeed a common massage technique in traditional Chinese medicine, but its main function can be summarized in eight words: "activating qi and blood circulation, and dredging meridians and collaterals." This is somewhat similar to the principles of common scraping and cupping techniques in traditional Chinese medicine. Regarding the folk saying of "detoxification," doctors suggest that this is more likely a "gimmick" used by merchants for promotion.
