The Progression Fitness inversion table is a key part of inversion therapy, which involves hanging upside down. Inversion therapy takes gravitational pressure off the nerve roots and disks in your spine and increases the space between vertebrae. Inversion therapy is one of the many ways in which stretching the spine (spinal traction) has been used in an attempt to relieve back pain. Always talk to your doctor before starting any new health regime and especially if you have suffer from back pain.