Flexion-distraction is a technique that involves the use of a specialized table which allows gentle stretching of the spine and allows the chiropractor to isolate the area of disc involvement while slightly flexing the spine in a pumping rhythm.
This latter has been researched extensively in USA in cadavers, where it has showed to create a ‘vacuum’ action that will eventually withdraw a bulged disc in to its own space.
In fact, this technique is used frequently, and proved successful, in conditions such as mild acute contained herniated disc. There is no pain involved in the treatment.
For more information refer to Cox technique.