A medical study published in 1983 by Dr. Goldman and colleagues showed that inverted patients experienced an increase in blood pressure and internal eye pressure. The media widely reported the study, warning that stroke was a potential result of inversion.
Two years following the inversion study, Dr. Goldman reversed his original position, stating, “New research shows that you are at no more of a stroke risk hanging upside down than if you are exercising right side up.” More in-depth research found that the body actually has mechanisms that prevent damage from hanging upside down. In fact, while oscillating (inverting with movement), some of the patients’ blood pressure actually dropped a few points. (*Note: these studies were based on patients in generally good health.
Dr. Goldman stated that the warnings to the public about the dangers of inversion were “grossly inflated” and that “in the 15 years these devices have been in use, there has not been one single stroke case reported, nor any serious injuries.” (This statement, to the best of our knowledge, is as true today as when Dr. Goldman made it 19 years ago).
Other universities, including Marquette, Iowa, and Portland studied inversion during this time, with results that also helped to vindicate inversion as a healthy physical activity.
If used conservatively inversion therapy is very very safe! As with any new activity, especially inversion it is a good idea to start slow and stay at very mild angles for the first week or so. Most people will find the 40-45 degree position the angle they will use most often once they acclimate to the table.