Coin rubbing

Gua sha (刮痧) is a technique used by practitioners of Traditional Chinese Medicine.

Gua sha involves firmly rubbing a person's skin with a ceramic soup spoon or large coin. The goal is to relieve stagnation, or in other words, to clear some illness from the body by getting it to move. Gua sha is used commonly on respiratory illnesses, for example, where the skin of the upper back, neck, and chest may be rubbed. Gua sha is known for leaving red and purple marks on the skin that look painful but are not. Well-meaning practitioners of western medicine are sometimes shocked at the sight of these marks and fear that a child with the marks has been abused. For professionals in this position, it is helpful to be familiar with the appearance of gua sha marks and to understand its traditional therapeutic value. It is helpful to be able to make the distinction between gua sha marks and signs of abuse. Gua sha is not known to be harmful. The technique called cupping also leaves distinctive, bruise-like marks on the skin, but is also harmless.

In 2001, a movie called "Gua Sha" (aka "The Treatment") was made addressing this practice and the cultural misunderstandings it causes. The movie stars Tony Leung Ka-Fai.