Re: Is hanging upsidedown lethal (for a long time)?

There are a number of reasons to suspect that hanging upside down--or 
inversion therapy, as proponents designate it--should have significant 
health risks.  

To be brief, blood returns to the heart via the veins which do not have a 
specific pump.  While the heart circulates the blood, much of the return 
from extremities results from compression of the muscles.  The head depends 
greatly on gravity.  In cases where the brain suffers from increased 
pressure--trauma, tumor, hemorrhage, et cetera--the degree of head elevation 
can significantly effect venous drainage and overall intracranial pressure.

Thus, it seems reasonable to suspect that the brain will suffer from 
decreased venous return, at least with chronic use.  One can extend this 
further to involve increased pressure in the eyes.

Furthermore, one may wonder about the effect on redistribution of blood flow 
in the lungs.  

One may also wonder about the proposed effect of inversion therapy.  Does 
relatively short periods of inversion significantly affect the normal aging 
of the back in an upright person?  As with many popular therapies, this has 
its proponents, and a simple search yields many pages selling instruments.  
They often cite old studies which, frankly, conclude little about long 
term benefits versus risks.  The theoretical basis of this and other 
traction therapies for the lower back involves the concept that they 
increase the distance between the vertebral bodies with a resulting decrease 
in the pressure in the discs.  The larger reference below (Rothman) reviews 
different proposed therapies.  The authors note one study from 1973 (Weber), 
demonstrated no significant clinical benefit when compared to sham 
treatment.  With regards to inversion therapy:

"Using this technique, the patient hangs upside down from boots or other 
supportive devices.  This therapy is not without substantial risk in that it 
has been documented to produce changes in blood pressure and heart rate, and 
adversely affect intraocular hemodynamics.  Clinical trials supporting its 
efficacy are nonexistent and its use is discouraged by the authors 
(Rothman)."

Now, "suspect" health risks certainly does not "equal" health risks.  

What does SCIENCE [Cue cymbal crash.--Ed.] have to say about the risks?

Unfortunately, not much, currently. 

The individual who has published the most according to searches of medical 
journals is R. Goldman, who last published in 1984.  Rothman et al. cited 
his 1983 paper that demonstrated some ill effects.  According to one 
company, Goldman has toned-down the risks, but he has not published anything 
in the peer reviewed literature.  Furthermore, as Rothman et al. note 
regarding traction:

. . . the use of conventional or alternative forms of traction is not 
supported by rigorous studies.  All the studies reported above can be 
criticized because of major design flaws.  In studies that compare 
alternative forms of traction, superiority of one form over another is not 
demonstrated."

Thus, while the literature only suggests health risks and does not prove 
long-term risks, it also does not demonstrate any clinical benefit.

--Doctor X

References"

Wisneski, R, Garfin, S, Rothman, R, "Lumbar Disc Disease," in _The Spine_, 
3rd Ed., Rothman, R and Simeone, F eds., W. B. Saunders Company, 1992.

Weber, H, "Traction Therapy in Sciatica Due to Disc Prolapse," _J. Oslo City 
Hosp._ Vol 23: 167, 1973.

Klatz, R, Goldman, R, et. al, "The Effects of Gravity Inversion Procedures 
on Systemic Blood Pressure, Intraocular Pressure and Central Retinal 
Arterial Pressure," _J. Am. Osteopath. Assoc._, Vol. 82: 853, 1983.