The method involves a mechanical device intended to separate vertebrae and thereby to relieve pain.
This approach is a higher-
Both methods are variations on traction, again, using mechanical force to separate vertebrae.
The premise of all three methods, spinal decompression therapy, inversion therapy, and traction, is that vertebrae are too close together and need separation.
That premise is good as far as it goes -- but let's look deeper. Why do vertebrae get too close together?
Understand that vertebrae are linked together not only by discs and ligaments, but by muscles that control spinal alignment. When those muscles tighten, vertebral alignment changes; twists, curvature changes, and compression of neighboring vertebrae result. Muscles pull vertebrae closer together; the discs push the vertebrae apart.
Muscle tightness of this sort is supposed to be intermittent and temporary, as required by the demands of movement and lifting; muscles are supposed to relax (decrease their resting tone) when these demands end. However, when, for reasons related to injury and stress, this tightness becomes habituated (i.e., quasi-permanent), problems (i.e., back pain) result: nerve root compression, bulging discs, facet joint irritation, and muscle fatigue (soreness) and spasm.
This habituation is a muscular behavior (postural reflex pattern) learned by and stored in the brain, the master control center for all muscles. Learning is a matter of memory; when either prolonged nervous tension, repetitive movements, or violent injury occur, the memory of these influences displaces the memory of free movement and habituation results; people forget what free movement feels like and forget how to move freely. They fall into the grip of the memory of tension.
Muscles obey the nervous system, with all but the most primitive reflexes stored in the brain as learned action patterns that control all movement. There is no muscle memory other than what is stored in the brain; muscle memory is brain memory.
Knowing that, consider approaches that mechanically stretch muscles or pull vertebrae apart. What do they do to habituated muscular behavior? to the memory of tension? The answer: they temporarily induce muscular relaxation but do not restore the memory of normal tension and movement, which is acquired "learn-by-doing." We are genetically designed to return to our familiar movement patterns once outside influences end; we return to our memory of how we have learned to move and hold ourselves. Shortly after the end of therapy, our familiar movement behavior and muscular tensions come back because you can't change learned reflex patterns stored in the brain by stretching muscles; you can only retrain those reflex patterns by new learning of movement. If you want a lasting change, that's what you have to do.
So, the typical experience of relief after manipulative therapies lasts hours or days.
For some people, whose habituation is not that deeply entrenched, manipulative methods are sufficient; you know for yourself whether this is true of your experience; now you know why.
Here's a question: How could you relearn free movement?
The answer has two steps:
(1) Unlearn the habituated pattern of muscular tension.
(2) Relearn free movement.
The process involves recovering the ability to feel in control of the involved musculature in movement; it's a learn-by-doing process, not a mental process, only, but a process that involves both mind and body.
Wouldn't you prefer to be free of repetitive therapy? to be free of dependency upon a therapist and the involved expense? to be able to care for your own back? to be free and safe to do any activity you wish?
Those are good reasons to make note of the approach described, here (bookmark this page): getting back control of your own muscular tension.
Free yourself from the grip of the memory of injuries, stress, and repetitive movement, not merely at the mental level, but also at the bodily level.
Visit this page for first aid for back pain. See this VIDEO.
For chronic back pain, please see this page, which also contrasts conventional back pain methods (including spinal decompression devices) with an entirely new, more effective approach.