Gravity Friend or Foe?

All our life Gravity keeps us grounded. On the earth we do not spin off into outer space because gravity through centrifugal force pushes us down. This is a good thing.  Bone density responds to gravity’s pressure.  Astronauts lose bone density in zero gravity situations and get taller.  If our alignment is good,  symmetrical gravitational  forces keep us balanced, however, once symmetry  is lost, those same forces perpetuate disfigurement and dysfunction.  Forward falling heads go further forward, kyphosis sharpens, lordosis flattens, rib cages collapse into pelvic girdles,  internal organs nutritional sources feel the weight of gravity and starve themselves into malfunction  interfering with general feelings of well being.  We think we are just ‘getting old,’ but we are getting shorter.

The aging process has been blamed for the loss of height most adults experience as we age.  What if that height from the flattening of our disks and compression in our joints is simply our reaction to the never ending , persistent push of gravity?  What if those changes don’t need to be permanent? What if individuals can fight back, or for the non-violent, what if we can enlist gravity as our friend?

I believe Gravity is why gout attacks happen mostly in feet, heavy uric acid  crystals fall down.  I’ve been told most lung cancers start in the lower lobes of the lungs, perhaps because that’s where  heavier noxious particles settle.  The disks between vertebral segments tend to  shrivel and dry out making them less flexible and elastic under the constant weight of the skull and gravity squeezing liquid from them more quickly than it can be replenished.  What can stop the constant push? Knowing gravity tends to aim at the core of the earth, how about deliberately changing the position of your body relative to the center of the planet? Our bodies replenish supplies at night when we lie down to sleep and interact with gravity differently.   What happens if we, on purpose, go upside down?

Robin Williams sparked my interest in inversion.  Sitting upside down like Mork seemed fun and it annoyed my parents.  It also made me feel good.  I had chronic ear infections as a child. Going upside down made me a little dizzy,  made my face red, but when I came upright my ears drained.  I was hooked. 

*Note* There are several cautions and contraindications against inversion. Get your doctor’s permission, don’t be stupid, always start slowly and at least the first time, do not attempt upsidowning  alone.  There are several  strategies  you can use  to limit how steep of an angle you assume.   I store a large ball under my inversion table and leave it there for certain partially inverted exercises.

Basic Truths

Gravity always wins.
Wolff’s law

Wolff’s law is a theory developed by the German anatomist and surgeon Julius Wolff (1836–1902) in the 19th century that states that bone in a healthy person or animal will adapt to the loads under which it is placed.   This means  bone density can be altered by changing posture and exercise and why athletes  (with proper nutrition and lack of disease process) tend to have higher bone density than non athletes. What most people do not know is that specific areas of density with in a bone also changes according to the stresses and strains put upon them.   During the late 80’s  I listened to a  presentation of a research project where the examiner studied bone density in the femoral heads of people who were being transitioned from walking independently to having to use a walker for various reasons in order to show that changes in posture affect localized bone density. The results showed that over a years time that although the relative amount of bone stayed approximately the same, the location  of highest concentration of bone density shifted within the bone, actually making walker users at  higher risk of fracturing  the femoral neck because the bone density there decreased.

Davis’s law

Davis’s law is almost the same as Wolff’s law except it refers to soft tissue. Henry Gassett Davis developed traction methods in the late 1800s and his work  and was the inspiration for the Ponseti method of correcting club foot through serial casting.

“Ligaments, or any soft tissue, when put under even a moderate degree of tension, if that tension is unremitting, will elongate by the addition of new material; on the contrary, when ligaments, or rather soft tissues, remain uninterruptedly in a loose or lax state, they will gradually shorten, as the effete material is removed, until they come to maintain the same relation to the bony structures with which they are united that they did before their shortening. Nature never wastes her time and material in maintaining a muscle or ligament at its original length when the distance between their points of origin and insertion is for any considerable time, without interruption, shortened.”
Starlings equations

Earnest Starling a physiologist from the turn of the last century   actually developed equations explaining capillary exchanges. Basically  he defined how fluids in the body respond to pressures put on them and also noticed that bodies met an increase in circulatory demand with an increase in the number of capillaries. This video ( )  does a good job in explaining the equation.  With inversion, the pressures inside the body change and nutrition  reaches areas that are usually more difficult to access.  When  cellular nutrition improves cells tend to function better as do the systems that contain them.


Body systems that benefit from inversion

It is my belief that inversion, if not specifically contraindicated,  can benefit nearly every system in the body. The respiratory system, the musculoskeletal system, the lymphatic system, the nervous system, the circulatory system, even the digestive system benefit by changing  positions and having gravity work on them from different angles. What surprises me is that more people don’t realize the benefits.   If going from vertical to horizontal (lying down to go to sleep for instance) is recognized for it’s ability to provide rest and restoration to these systems, why does it not follow that a greater level of lying down…going into inversion,  might have other advantages to a living system as well.

From the moment I strap my ankles in and leave the vertical position I employ gravity as an agent of change.  Gravity works on every particle with mass. It can be used like a broom to sweep, the principles that govern fluids apply creating floods in  areas of drought, the push of gravity becomes the pull of gravity. Let’s look at some of the benefits to human biological systems.

Musculo-Skeletal System

Most people considering inversion are after relief from back pain, someone said it helps disks and can improve a golf game.  Inversion is so beneficial to  the musculoskeletal system that this system alone makes inversion worth pursuing.  At birth there is a fairly good blood supply to the disks between each bone in the spinal column.  After the end of puberty this blood supply decreases and inter-vertebral disks get the bulk of their nutrition from compression and decompression of the disks.  An increasingly sedentary populace follows compression with more compression as gravity pushes on the spine, and then continues to push as posture deteriorates gravity will magnify the effects of the rounded back, the forward head and helps to increase the rate and perceived permanence of our deformities. Most people typically don’t walk miles a day and that gentle slosh in the abdominal cavity that happens with a normal stride pattern, which  stimulates circulation, intestinal motility, and lymphatic efficiency is absent from most of our lives. Even with daily exercise, gravity constantly pushes down on these largely cartilaginous spacers and with time and/or improper mechanics they erode over time, like shocks in a car wearing out. New surgical techniques attempt to replace the bulk that keeps the bones from getting so close to each other that they put pressure on nerves exiting the spinal column.  Inversion allows for decompression to happen long enough to change the pressure, and give the disks a chance to ‘drink’ from the interstitial fluids and plump back up.

The act of inversion with the ankles in a fixed position also provides a bit of traction, so that if irregularities in the bone have left them slightly twisted because of unequal muscle tension, the bones slightly separate as the small muscles are stretched, rested, re-positioned as gravity does the thing it does…push down in an action that would be like lifting up if you were standing. Hips open, the muscles that create the  lumbar, cervical, and thoracic curves lengthen on all sides allowing the normal bending and reversal of curvatures to be restored.  Sometimes we are too tight to bend and this stretch helps correct that.  Between each set of ribs there are three sets  of muscles called intercostals, (one slanting inwards one outwards and one vertical eg \l/ ) Gravity’s usual work causes the upper ribs of anyone who bends forward to squash down on each other and pushes the lower ribs towards the pelvic girdle.   When intercostals shorten the ribs move closer together and can prevent normal motion in the thoracic spine.  Inverted, all three sets can stretch at the same time allowing for increased separation between the ribs allowing for greater flexibility in the rib-cage. This increased length allows for a greater inspiration capacity in the non muscular lungs.

The lowest border of the ribcage is both origin and insertion of the diaphragm muscle that rests under you lungs and heart, separating your chest cavity from your abdomen where the majority of your organs lie.  The weight of the abdominal contents on the diaphragm causes that muscle to work against gravity.  This weight causes resistance to the usual movement, as if the diaphragm was lifting weights (it is) regular practice makes the diaphragm stronger so when it is no longer inverted it is better at doing it’s job of supporting breath.

Most people do not realize that the only bone to bone attachment of their arms to the body happens at the breast bone.  Their attachments are usually less than an inch apart, in fact,  arms are more attached to each other than they are to the rest of the body.  Shoulder blades, that the actual arm bone ‘plugs into,’ have no bony attachment to the body other than the almost pencil thin joint at the outside end of the collar bone.   So,  when going upside down, the shoulder girdle can drop away from the torso. The weight  of the arms will help the muscles that plaster the shoulder blade to the ribs lengthen and swing free from the body. Gravity at this point will create more room in the subclavian space (under the collar bone) and allow greater lymphatic mobility  there.   Frozen shoulders are sometimes ‘melted’ as different angles of motion are suddenly available because gravity induced separation.  Caution does need to be used  if inversion creates pain, pillows, yoga balls, angle discretion need to be employed to support the body in non-painful stretch positions.

Many people with chronic or recurring headaches benefit from inversion because it creates distraction of the skull from the neck.  Gravity’s downward pull now stretches connective tissue,  frees nerves, blood vessels, increases flexibility of the ligaments as the body moves towards gravitationally induced symmetry. It is much easier to feel where you are tight when gravity is suddenly pulling you in a different direction.  If tightness in the hips  results in the head or neck being rotated in order to keep the eyes on the horizon,  inversion allows for a re-set there as well.   The weight of the  brain being used to correct the neck can be pretty amazing.  If this is the purpose, or an extended inversion session is planned for someone with chronic neck issues, I usually recommend use of something curved to go under the neck (like a 2 lb yoga ball or a stuffed animal, a horizontally positioned pool noodle or a rolled towel)  so that it is coaxed to stretch in a position that supports a stable curved neck.   I also will do this to encourage a curved lumbar spine as well.

Speaking of the change of pressure on the inside of the skull by the weight of the brain, for those who practice Cranial-Sacral techniques, there have been times I’ve used inversion to create still point. The sphenoid bone responds to gravitational pressures on the jaw, the soft palate, the fluid distribution in the sinus, stretches on the optic nerve attached to eyeballs that rest in slightly different places. The sutures (joints of the cranial system) receive extra nutrition with the change of nutrition provided by capillary expansion with gravity pushing towards the head instead of the feet.

Knowing Wolff’s law says “bones grow according to stresses and strains put upon them” explains how inversion changes the orientation of the bones, thus the demand, who knows how osteoporosis  is affected by upsidowning, I’ve never seen a study but the body wide change in alignment that happens because of the temporary decompression probably helps with that as well.

The major job of muscle is to move bone. Lengths of muscle fibers, fiber strength and integrity, blood flow, nutrition and  tendon flexibility all influence the stability of muscles and environment bony attachments. I frequently feel stronger after simply resting in an inverted position,  it follows that inversion will add benefit to almost any other workout.. Muscles respond to their resting positions.  Inversion maintained for over 30 seconds, essentially gives a person’s whole muscular system a whole body-wide gentle stretch that even stretches the blood vessels and nerves that traverse it.

Circulatory System

The heart acts as a pump, with one big squeeze it pushes fresh blood out of its chambers this travels both up towards the head and down towards the feet. This electrically generated push is the ‘beat’ of the heart and happens 60 to 90 times a minute in most  adults.  The push needs to send blood up to the brain, down to the feet and everywhere in between. where the force runs out of push gravity takes over.  Arteries are the vessels that transport blood away from the heart, the vessels branch off as a delivery system  becoming smaller and smaller until  and somewhere at the end line they become capillaries and voila… at the end  of the capillary network the vessels come together in the reversal of the branching system, become larger again  and go back to the lungs as veins. Veins have one way valves so when the arteries transport the pushed blood gravity does not overpower  the force of the heart and keep the blood in the feet, or what ever position is furthest ‘down’. Nutrition is delivered to the cells and waste products are picked up to be removed from the system.   When inversion changes the orientation of the body, gravity ensures that the brain gets more blood, because less force is required to get there.  The largest cautions and restrictions with inversion have to do with the brains capacity to handle the increased volume of fluid that finds itself in the cranial vault. But the beauty is, with regular graduated usage, the capillary system in the brain expands and lessens the probability of  vascular destruction that sometimes happens with sudden exertion.  For people who have  poor vascular return, inversion allows the veins a short rest, and aids in complete venous return.

Inversion is a preventive measure against peripheral vascular disease. The change in pressure of flow encourages greater responsivity of the smooth muscles in  blood vessels. Thanks to Starlings equations the response is  even predictable.

Inversion improves brain function dependent on oxygen for it’s efficiency. Because of the gravitational induced proliferation of the capillary system created by going upside down, people who do not think well because of oxygen deprivation can have a tool for at least partial restoration.  When I have a task that I need to think more clearly for, I find going upside down first at least seems to increase my mental alertness and acuity.

Inversion improves circulation, in that blood vessels–both arteries and veins–feel the effects of compression.  Most noticeably, when the weight of the abdominal organs are lifted away from the arteries of the pelvic floor, any blood vessels have been compressed or kinked by the weight of the abdominal contents become decompressed, and the interstitial fluids trapped by internal organs can now flow away and as gentle stretch is applied to the veins and arteries  anchored in the feet. Sometimes a muscle that has been in spasm or even an especially hard piece of constipated poop shifts and stops compression of a blood vessel that has contributed to cold feet or even muscular weakness. when returning to vertical, gravity will direct the offending structure to a new location, but in a longer, better nourished, more relaxed state. The change in the delivery of blood to the abdomen assists in improvements in the digestive system


Digestive System

The same inversion that removes the abdominal organs away  from  the pelvic floor stretching the blood vessels tethered to the ankles, stretches the descending colon which is tethered to the un-moving anus.  This is good news for the constipated. Using an inversion table can be a way of creating artificially induced  peristalsis (the smooth muscle motion that moves contents through the intestines). One of my favorite feelings when I go on my table is that point at which I feel my intestines release and slide towards my diaphragm. When this happen, on my inversion table my body actually slides to an increased angle if it is not blocked by my ball. There is a slow stretch that happens as the interstitial fluids that bathe the abdominal cavity follow the rules of gravity on fluids and they seep towards the diaphragm. I love that point when the intestines feel like they disengage from  their position and slide, it always feels like…….relief. My tailbone is glad to free of the weight of them. The ~ 8 inches of rectum that holds the processed poop after it leaves the descending colon is remolded now by gravity and internal sausage casing straightening out kinks changing internal lubrication.  Frequently a person who begins an inversion practice will notice a change in their bowel habits, and though not a cure for constipation, I have seen inversion  ‘jump-start success’ in that matter.

Upsidowning stirs the stomach fluids, stretches the esophagus, loosens the tongue, stretches the attachments to the hyoid bone, gently squeezes the glands in the throat, all of these are good reasons to only invert on an empty stomach!

I believe the other digestive organs benefit from the temporary change of weight distribution as well. If an organ is retaining fluids the ‘change in cabin pressure’ may stimulate a gentle expressing  of waste products out of  digestion’s accessory organs, the gallbladder, liver, and pancreas. The change in arterial flow can provide the equivalence of high-tide on the beach when sea-weed is reclaimed. Not so drastic as a tsunami but a controlled outburst of nutrition without any actual increase in demand.   It is restful.

Because so much of the absorption of nutrition from the foods we eat happen in the intestinal area changing pressure and position is like wringing out a towel before hanging it on the line…yes it will dry normally but this improves the ease of this task. especially if  there have been stagnant fluids in the abdominal cavity.  Some of this ‘stagnation’ is the product of an inefficient self cleaning mechanism in the body, the lymphatic system.

Immune (lymphatic) system

The whole of the immune system is beyond my scope of education, but the lymphatic system is an important part of the body’s defenses. The known number of lymph nodes has expanded in the last hundred years. They are illusive. Usually only noticed or cared about when people have colds and feel like they have balls of molten lava under their ears, lymph nodes. Most people don’t realize they have more lymph nodes and lymphoid tissue in their abdomen than any other part of  their body. There is a large lymphatic  drainage channel in the upper rib cage below the collar bone (subclavian space). in addition to being part of the immune system, the lymphatic system has been described both as part of the digestive system and the circulatory system. It transports and processes fatty acids from the intestines and delivers it to the circulatory system.

Lymph is partially solid but usually is mostly liquid, and follows the rules of gravity on liquids.

  • Liquids seep down to the densest sediment
  • liquids can contaminate their environment, alter it                                                                       or be changed by it. “which is changed more the tea or the water?”
  • Agitation increases assimilation eg. a tablespoon of sugar dropped in water could take hours to dissolve where rigorous stirring has it blended in less than a minute.
  • the more sediment is added to liquid, the more the liquid resembles and responds like mud.
  • Liquid splints can protect joints from  further trauma
  • Liquids left untended can get crusty due to evaporation .
  • Liquids lubricate
  • Liquids  can wash or seal surfaces,
  • some solids are liquids some times

…consequently  deliberate positional changes affect how certain cells and interstitial materials react in the body;. like the sands in an hour glass, or a Peruvian rain stick the waste products slide from stem to stern and lymph responds to gravitational pulls.  If I have a little cold, upside-down fills my sinuses, upright drains them, and I have gone up and down until my stubborn stuffed ears have started to drain.  When lymph nodes are  ’emptied’ they are better able to process waste products and manufacture T-cells and other immune system defense mechanisms.  When they are ‘over-loaded’ they do not seem to work as efficiently. In practical purposes, if the large network in the abdomen is overloaded, the armpit, throat and sinuses will not have the optimum emptying capacity…Where will the garbage go if the landfill is closed because it is full. The body becomes stagnant, moving lymph is like a river that is self cleaning and makes it’s environment sweeter and more functional.

Inverted the weight of the intestines helps to empty the nodes in the mesentary, the connective tissue that surrounds, cushions and separates organs. Lymph has been categorized as circulatory system, digestive system, and immune system tissue. Take your pick, but take care of your lymphatics. Inversion and vibration will help it’s efficiency and make most people healthier.

There are organs that have lymphoid tissue, while not nodes, still work in connective tissue fighting infection, repressing cancer cell proliferation and other functions scientists still haven’t figured out yet. This tissue fulfills the function of nodes in each organ while helping the organ do it’s ‘regular job’

Nervous System

People sometimes forget nerves need length and flexibility to keep up with the demands the body puts on them. Nerves need to avoid getting pinched between joints or in scar tissue, they need a good working relationship with the circulatory system to ensure good nutrition and electrical conductivity, and ultimately each nerve is governed by brain health. There are several ways the nervous system can malfunction. Inversion cannot help genetics, but damage that is due to trauma, ‘poison’ from static inflammatory materials that congest nerve pathways, pinch of asymmetric muscle pull and bone or cartilaginous encroachment can be mitigated by  an inversion practice.

Brain function has been said to be improved by the change in oxygen delivered by the gravity increased demand that leads to greater capillary construction, and improved cerebral spinal fluid flow improves the cranio-sacral .rhythm which seems to clean the inside of the spinal column. The sinuses that deal with influx of liquids that drift down from other systems when the body is righted they seem to have a greater responsiveness and expansiveness.

Neural tension is something some physical therapists work with to lesson several types of pain and a gentle slow stretch of the nerve through it’s pathways will often free motion, and decrease that type of pain.  Distraction on the cranial nerves even seems to have a calming effect on the  autonomic nervous system and as breathing patterns change based on all the aforementioned alterations in muscle, blood, nerves breathing improvements tend to occur. What a boon that is to the body.

Respiratory System

Without oxygen there is no healing, without blood there is no oxygen, without breathing there is no way to get oxygen into the blood.  Anything that makes the gas exchange in the lungs more efficient is good for your whole body. Inversion helps the respiratory system in a multisystem synergistic manner.

The lungs have no muscle tissue. Unlike the intestines that have smooth muscle squeezing contents through chemical washes and filters, the lungs fill and empty largely by what could be called osmosis. Pressure impacts how deep the exhale and how full the inhale can be.   For our purposes, looking at only the changes a gravitational shift has is an encouragement to me to use the table on days I might not feel like it.  When going upside down, the hard, heavy particles that get trapped in the lungs  by being breathed in and ‘sneaking’ past other filters, but filtered out of the body by the lungs begin to loosen from where they may be embedded and drift from the lower lobes towards the upper lobes where it is generally easier for the body to work it out by coughing.

The weight of the liver and stomach on the diaphragm adds a downward pressure that makes a more complete exhale feel much more natural while inverted.  The diaphragm muscle itself must work harder as it pushes against gravity.  The constant push of organs against it may even increase that important breathing muscle’s length and flexibility…wouldn’t that be a boon in time of instant and urgent need for air?   This same resistance is an argument for regular practice because it strengthens this muscle which is not only necessary for breath support, but is also flexible enough to work independently from the muscles on the front side of the back of the abdominal cavity (eg psoas). The organ weight may also help to decrease retained fluids from the chest cavity through gentle expression and osmosis.

The force of gravity on the ribs helps to expand their range of motion, increasing the accordion method of expansion as well as the rotational ‘Slinky-esque’ bounciness afforded by the 3 sets of intercostal muscles, elongating and finding their own voice learning the difference between up & down, in & out, and around & back.

The increase of rib motion allows for greater range of motion in the sternum itself as the ribs gently rock on the breast bone the heart has a softer surface to work in.   At the same time the breastbone increases it’s flexibility the expansion of the rib muscles encourages gapping and improved nutrition to the inter-vertebral disks of the thoracic area.  I have worked with a number of people with history of asthma and chronic bronchitis whose symptoms abate with inversion work as the automatic increase in complete exhaling, seems to make their bodies more receptive to inhalations effectiveness. There are simple exercises that may help scoliosis sufferers decrease effect of constant downward pressure on their aberrant  curves.

The improved function of the lungs generally leads to improved oxygenation in the circulatory system, which brings us full circle. Go on try it…

Turn Your World Upside-Down!