(Zero) Gravity and Human Movement | Understanding Man, Movement & Mars

On earth there is an omnipresent force weighing down on our shoulders, allowing us to stand on our two feet and helping bring oxygen and nutrients to every tissue in our body.   I am referring to the only constant in the world – gravity. 

Although poorly understood and often taken for granted, gravity is the evolutional life force which has defined planet Earth as we know it.    In EBFA’s education we explore how gravity allows us to “feel” ourselves, by connecting to our proprioceptive and postural systems and allowing us to stand and move.  

I like to say, gravity is the sensory driver to human posture and movement. 

If the above statement is assumed to be true, then can you manipulate gravity to improve a client or patients posture and movement? Could we somehow use gravity to improve the postural awareness after a stroke?   Or to increase foot strength to prevent plantar fasciitis and stress fractures?

I often find that in order to fully appreciate something, we need to experience life without it. 

In the case of gravity, what do you think will happen when we take away this constant force which stimulates the very systems that define man?   

For this, we need to turn to a hypo gravitational field, or a (wo)man on a mission.  

Weightlessness and the Effects on Astronauts 

Probably one of the coolest jobs is to be an astronaut.   Imagine being at a dinner party and telling someone that you travel to outer space for a living!    Although I never aspired to be an astronaut, I can appreciate the training and dedication they have for the advancement of man.   

I first became fascinated with the effects of zero gravity when I was contacted by NASA to integrate our Naboso Insoles and Mats into the astronauts mission preparation and recovery regimine.   The astronauts were coming back with severe foot pain which which creating an issue with the rest of their recovery program.   This is when I realized that in order for me to fully appreciate life with gravity, I needed to understand life without gravity. 

Effect #1 – Loss of Orientation

Weightlessness causes several key systems of the body to relax, as they are no longer fighting the constant pull of gravity.   One of the first to relax is the vestibular system, or our primary sensory system for orientating ourselves in gravity. 

Orientation and the vestibular system are so important that they are the first sensory system to develop in utero and is being shaped before a baby is even born.   

In space, an astronaut’s sense of up and down gets confused and the vestibular system no longer can figure out where the ground and the ceiling are.   This can lead to sensations of vertigo, nausea and impaired balance. 

On Earth, a loss of orientation can have the same effect but since are in gravity, we can use it it to re-establish orientation.    I’ll give an example of how I apply this to myself and then to my patients. 

In my free time I train aerials, where a large part of this art is spinning.  A couple weeks ago one of our routines required us to spin while inverted. This completely messed up my vestibular system and sense of orientation.  I got off the straps nauseous, dizzy and in a sympathetic state.   To reset myself I had to lay down, feel the ground and reconnect to my sense of body awareness.  

For a patient, we can mimic what I did without of course having them lay down.    To optimize vestibular orientation we need to know where is the ground.   Feel the feet.  Connect to the feet.    Using the sensory insoles from Naboso is a great way to achieve this.    Teach the client that anytime they start to lose their orientation to go back to “feeling the ground”.   In psychotherapy this is called anchoring.   

Effect #2 – Impaired Proprioception

Proprioception is one of the main ways we related to gravity.    It is through our proprioceptive system that we control our center of gravity, or sense of balance.    Proprioceptors are found throughout our body, surrounding every joint and within muscle tendon and fibers. 

In space, astronauts experience a disruption in their proprioceptive system, and start to lose the ability to differentiate how their arms, legs and other parts of the body are orientate to each other. 

In a NASA report one astronaut stated, “The first night in space when I was drifting off to sleep, I suddenly realized that I had lost track of my arms and legs.  My mind could not tell, if limbs were there.”

Now imagine if you had a client with neuropathy ir the inability to feel if their feet or lower legs were there.   Or even a patient who sprained their ankle leading to a disruption in proprioceptive control.   

How would this compromise their movements?

We can feed into the proprioceptive system by increase their sense of limb awareness or gravity.   Some of my favorite ways to do this include kinesiology tape, compression sleeves or apparel and ankle or wrist weights.   

Effect #3 – Decreased Blastic Stimulation 

To be blastic is to build – with the stimulus to blastic activity being stress.   Both our bones and nervous system are designed to be blastic.    And longevity is really about ensuring we stay in a blastic state. 

When it comes to bone density, load bearing or gravitational stress is necessary to maintain healthy bones with age.   It is not surprising then that astronauts in zero gravity will experience some degree of bone loss in space. 

NASA research has shown that on average an astronauts bone density drops at over 1% per month.  By comparison, the rate of bone loss for elderly men and women on Earth is average 1% to 1.5% per year.  

So how is bone density increased with gravity?   

Many think it is gravity itself that builds bone density, but it’s more complex than that. What stimulates blastic activity is really movement in gravity.   If we just sat in a gravitational field we would still lose bone density – take our sedentary lifestyle of today and the rise in osteopenia and osteoporosis!

Moving in gravity means experiencing vibrational forces every time the foot strikes the ground, with the vibration being the stimulus for the osteoblasts to build bone density.   

We can apply this to our patients and clients through bone stimulators when they have a fracture, by integrating whole body vibration platforms and by exercising on surfaces that vibrate (wood or dirt) and in shoes without cushion, or even better, barefoot. 

The other form of blastic activity has to do with our nervous system and is referred to as synaptoblastic, or the development of new neurosynapses in the brain.    

To be synaptoblastic is to be in a state of neuroplasticity.     To be in a state of neuroplasticity requires one to be challenged proprioceptively and cognitively in what’s called dual tasking.   

For an astronaut to present with cognitive or motor decline post-mission isn’t surprising as we previously mentioned that many neurological input systems are just not needed in zero gravity.  Without the constant neurological challenge we will see atrophy.   

When we think of protecting the synaptoblastic state of our clients we want to challenge the input systems.   How can we increase the sensory input to the proprioceptive, visual and vestibular system and then simultaneously challenge their cognitive tasks?

We go into all of this in a recent webinar we did called Gravity: Friend or Foe. I encourage you to listen to this free webinar.

Effect #4 – Muscle (and Fascial) Wasting 

This one should not be a surprise as without gravity there is no effort that is needed to move.   On Earth our muscles (and fascia) are what resist gravity allowing us to stand upright.  

In addition to posture, our muscles also protect our bones, contracting against the vibration of ground reaction forces.   Without movement, there are no  vibrations to contract against.   This is where foot pain in astronauts comes into the picture. 

The purpose of the foot intrinsics, or plantar muscles, is to contract isometrically to stiffen and create foot stability.   A stable foot is required for the absorption and transfer of impact forces and energy.    When we take away movement and vibrations to the foot we will experience atrophy and denervation of the foot muscles.  

What we are seeing in the astronauts is essentially what I see is patients who chronically wear thick cushioned shoes and orthotics – weak feet. 

To counter this we need to ensure that sufficient sensory stimulation is entering the feet.   Naboso Insoles, less cushion in the shoes, barefoot training and vibration platforms. 


Now perhaps you cannot relate to the zero gravity effects of an astronaut but couldn’t we make some parallels to the sedentary lifestyle of many adults (and children) today?

To unlock the power of gravity is to move, and to move is to live. With gravity as the sensory stimulus that shapes our movement patterns, can we not say that movement is sensory and therefore life is sensory?

I’d argue yes. Life is sensory.


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