You guys are looking at bad examples of "fire cupping." In fire cupping, you place a flame inside a glass jar to create a vacuum, then place it on the muscle group you want to cup. What you see here is someone who actually heated up the rim of the glass jar and burned the patient. In other words, they didn't know what they were doing and they screwed up.
The cups used by Phelps's therapist have one way suction valves, so they can be place on the skin and the air can then be pumped out, creating the vacuum and the seal. Depending on how much they pump out, they are pulling the soft tissue up away from the bone, not a direction it usually goes. Someone said reverse massage. That sounds about right. If there is enough of a vaccum, it will pull blood out of the vessels and you will see the circular bruises. Typically they would place a little salve or massage oil on the skin first, then the cup can be moved. For instance, up and down along the paraspinals.
As is typical, the people who are slamming this therapy have cherry picked the worst of the worst cases. Is it a panacea or some miracle cure? No. Anyone claiming so is misguided (I think we may have some misguided people in our own field too). It is just another therapy/modality that many people find helpful for pain. Properly performed it is non-invasive and very safe.
