Cupping is a therapy that helps treat musculoskeletal disorders by using suction to create negative pressure underneath the cup. Originally fire was used to create the suction, but more recently a simple pump is used. The negative pressure helps to decompress the area by lifting the skin and the layer of tissue underneath the skin, the fascia, up into the cup. This creates space for the underlying tight muscle to lay down and relax. Cupping also helps bring blood flow to the area in need. Blood carries important nutrients which help with tissue healing. We use myofascial decompression to address compensatory movement patterns. This is done by adding movement with treatment. Movement can be in the form of sliding the cups over the necessary tissue or leaving the cups static while moving body parts.
The above information comes from springforwardpt.com