Inversion table is used as a treatment primarily for back pain. It is designed to utilize gravity and create some traction in the spine and pelvis, which can take pressure of compressed joints, discs and nerves. Inversion therapy usually involves laying at a downward angle, not hanging completely upside down. The effectiveness of using inversion tables for back pain is not well studied, but anecdotal reports suggest that some people do experience at least short-term relief. http://www.yunpaosports.com/inversion-table/