Inversion tables/gravity boots - woo-woo or legit?

[dissonance]

So I was up late last night, and I was watching The Shopping Channel (something about the relentless cheerfullness of the hosts even when shilling the crappiest products known to man helps lull me to sleep), and they were demonstrating this inversion table thing.

Those whole thing seemed very woo-woo, with vague references to studies and lots of talk of ancient Greeks and how inversion would Change! Your! Life!, relieve back pain, make you happier, healthier, smarter, and it might even wash your car and paint your house for you. So it all seems highly dubious.

On the other hand, I know when I'm at the gym, I'll frequently do dead hangs after I finish my chin-ups (hang from the bar - not inverted, obviously - for 20-30 seconds), and it does make my back feel really good, although that could just be the muscles relaxing after working through the chin-ups. So does anyone know what the deal is with inversion tables and gravity boots? Is hanging upside down really beneficial? Or is this yet another dubious product based on stuff that sounds like it should make sense but for which there is no actual proof?

 

[wayrad]

Is hanging upside down really beneficial? Or is this yet another dubious product based on stuff that sounds like it should make sense but for which there is no actual proof?

All I know is that it makes the money fall out of your pockets.

 

[exarch]

Originally posted by dissonance
On the other hand, I know when I'm at the gym, I'll frequently do dead hangs after I finish my chin-ups (hang from the bar - not inverted, obviously - for 20-30 seconds), and it does make my back feel really good, although that could just be the muscles relaxing after working through the chin-ups. So does anyone know what the deal is with inversion tables and gravity boots? Is hanging upside down really beneficial? Or is this yet another dubious product based on stuff that sounds like it should make sense but for which there is no actual proof?

I always thought that was what chiropractors did, stretch your spine and the muscles that make it tense up. Turns out they are pretending it's more than that. Either way, hanging inverted does relax your back, but I'm not quite sure if it's all that good to hang upside down for too long, especially since your head is not used to having that much blood pressure there.

 

[popsy]

Some years ago when inversion was advertised to cure all, it was noticed that the eyes were vulnerable to the increased pressure from being upsidedown for extended times. Blood vessels could pop and I suppose if the right wrong ones did, blindness could ensue.

 

[Rolfe]

Some years ago when inversion was advertised to cure all, it was noticed that the eyes were vulnerable to the increased pressure from being upsidedown for extended times. Blood vessels could pop and I suppose if the right wrong ones did, blindness could ensue.

And they still allow bungee jumping just WHY, exactly?

Rolfe.

 

[exarch]

Originally posted by Rolfe
And they still allow bungee jumping just WHY, exactly?

It isn't prolonged exposure?

 

[Rolfe]

It isn't prolonged exposure?

That, yes, but have you thought about the sheer magnitude of the pressure in the retinal vessels at the bottom of a bungee jump? I wouldn't try it for all the tea in China. I believe there have been a few unfortunate incidents, but I can only assume they aren't common enough to justify a ban.

Rolfe.

 

[Soapy Sam]

I recall a physiotherapist friend being horrified when I did a bungee jump. She seemed to think my head might fly off or something. My recollection is that the deceleration was pretty gentle- certainly less than fairground rides. The acceleration in freefall of course carries no unbalanced force at all. Disorientation was pretty severe, albeit brief, but I can't remember feeling physically stressed.

 

[exarch]

Originally posted by Rolfe
That, yes, but have you thought about the sheer magnitude of the pressure in the retinal vessels at the bottom of a bungee jump? I wouldn't try it for all the tea in China. I believe there have been a few unfortunate incidents, but I can only assume they aren't common enough to justify a ban.

I used to do gymnastics, and I remember I had to clench my hands into fists during sumersaults to avoid my fingers from hurting.

 

[Bikewer]

I don't think the forces generated in bungee jumping are anything near what a present-day fighter pilot experiences in high-G manuevers; doesn't hurt them much. Unless of course, you black out and crash....

 

[exarch]

Originally posted by Bikewer
I don't think the forces generated in bungee jumping are anything near what a present-day fighter pilot experiences in high-G manuevers; doesn't hurt them much. Unless of course, you black out and crash....

Fighter pilots know well enough that loopings where the cockpit is facing outward, are more dangerous. Most of the G forces they'll experience are the other way around, where blood rushes to their legs (and they have their flight suits to counter some of the effects of that).

The body is most capable of sustaining accellerations from back to front, which is why astronauts being launched are reclined back in their seats, facing upward.