For quite some time, many people have been using gravity-inversion devices such as inversion tables (ex.Teeter Hang Ups, etc)to hang in the upside-down position with the belief that this maneuver can offer relaxation, facilitate a strength-training response, or relieve lower back pain. Although it’s yet to be demonstrated that inverting the body is of any practical or physiologic benefit, it is now apparent that it can cause a significant elevation in both systolic and diastolic blood pressure.
In one study, of 50 normotensive men and women, body inversion caused systolic blood pressure to rise from an average of 114 mm Hg to nearly 140 mm Hg, whereas diastolic pressure increased from 76 to 91 mm Hg. In addition, these changes continued throughout the 3-minute duration of the inversion maneuver. Such a hypertensive response during inversion at rest in healthy individuals, as well as significantly increases in intraocular pressure (IOP) — the pressure caused by the fluid inside the eye that helps maintain the shape of the eye. Control of IOP within the correct physiological range is necessary to maintain the anatomical conditions that is required for optimal refraction and consequently vision.
Since having an eye pressure that’s above normal can places a person at a higher risk for glaucoma, and hypertension can also impose a chronic strain on the cardiovascular system, this raises concern about the possible consequences of inversion tables for hypertensive people and the cautiousness of recommending exercise in this position without closely monitoring the blood-pressure response.
This is not an attempt to debate whether or not inversion tables are effective back pain relief devices. The message I would like you to take home is that, because gravity inversion devices such as inversion tables are known to cause an elevation in intraocular and blood pressure, one should be extremely cautious when using these devices, or make sure they are monitored by a medical professional, just to be on the safe side.