Ligaments have a limited blood supply and thus do not heal easily. Sometimes they fail to heal completely, thus leaving scar tissue. Scar tissue is not as strong or flexible as regular ligaments or muscles and leaves the area stiffer and weaker. This is how your back ages and becomes less flexible. Without regular stretching, ligaments can become stiff and may increase the risk of injury.
Inversion can help.
Simple, gentle stretching can help scar tissue become more flexible and more strong, or absorbed and replaced by more normal ligament and muscle tissue. This strengthening can help to prevent a re-injury. Although there are exercises to stretch parts of your back separately, inversion helps to gently stretch all the ligaments encasing your spinal column at once. Muscles and ligaments require regular stretching to maintain normal flexibility and strength. Inversion helps to gently stretch muscles and ligaments.