These clinics provide cupping service. Cupping is based on ancient Egyptian, Chinese, and Middle Eastern cultures that believe the suction of the cups mobilises blood flow to promote the healing of a broad range of medical ailments. A common method is to heat the air inside a glass cup before placing it on the back of the patient. As the air cools it contracts, causing a mild vacuum pressure to be applied which raises the skin and flesh into the cup.  Even in skilled hands this process will leave a mild welt on the skin which will take a week or two to pass. Be warned, you don't want to do this the week you intend to wear a slinky evening dress!