Gravisensing | Gravity as the Sensory Driver to Movement
One of the most sensory complex movements we do every day is walking, with the sensory stimulus and driver of that movement pattern being gravity.
This omnipresent weight on our shoulders not only reminds our nervous system that we are on planet Earth but it also helps establish what is called body awareness.
Body awareness, or our sense of self in relation to our environment, is necessary to navigate our body in space while dynamically maximizing efficiency and minimizing injury.
Gravity & Global Body Awareness
When we think about gravity, body awareness and the dynamic control of walking, we want to think of the body as a global unit with smaller local units or joints.
The global body unit has a main center of gravity or center of stability which is just below L5/S1 and lies in front of our body. Any shift in our center of gravity will result in movement. Now that movement can be coordinated such as in the case of walking, or uncoordinated as in the the case of a fall.
What determines if movement is coordination or uncoordinated is our relationship to gravity and the perception of a shift in our center of gravity. To take it even further this gravitational awareness and relationship is not only happening on a global scale but also locally at each joint in our body.
Gravity & Local Joint Position Sense
Our joints perceive gravity via our proprioceptive system and the length tension relationship of structures that surround a joint. This is referred to as joint position sense.
Joint position sense simply means that in order to control a joint, one must be able to not only perceive the joint, but more importantly be able to perceive a shift that joint. To take it even further, it is the rate at which a joint is shifted that determines the ability to control a joint.
Let’s look at a quick example to understand this better.
Joint Position Sense & Ankle Sprains
An example of body awareness that is joint specific is the perception or sense of our foot and ankle relative to the ground.
When we step off of a curb, the accuracy of our foot placement is dependent on our ability to sense the height of the curb, combined with the acceleration of foot fall and timing of ankle joint position sense at foot contact.
Any delay or inaccuracy in foot awareness can result in a misstep or even an ankle sprain. Fatigue, injury history, age and footwear all can contribute to a delay in foot awareness and perception of the ground.
Enhancing Gravisensing & Body Awareness
At Naboso, we work with a lot with individuals with movement disorders and chronic neurological conditions – conditions that greatly alter the nervous system’s ability to perceive gravity, the body and the joints.
Research has demonstrated a direct correlation to fall-risk and delayed perception of a shift in center of gravity. Or simply stated decreased body awareness.
Our priority and step one in enhancing movement coordination and reducing falls in these individuals is to increase their body awareness globally and joint position sense locally.
This means turning to the nervous system to enhance its perception of gravity.
Remember gravity is pressure, tension, vibration.
Below are three of our favourite modalities for increasing the perception of gravity and body awareness.
Gravisensing Tip #1 – Weighted vests & wrist weights
Have you ever seen the ads for weighted blankets ads? They claim to calm an anxious person or help people sleep better?
Weight blankets, like weighted vests and wrist weights, help connect an individual to themselves. It essentially says “here I am!” The added weight of these products help someone with poor sensory input to essentially turn up the volume of the stimulus of gravity.
Research has demonstrated efficacy in using weight vests in those with balance issues, post-stroke and spinal cord injury. Similarly wrist weights, such as those by Bala Bangles, can help emphasize the reciprocal arm swing of walking which is critical in the coordinated movement pattern of walking.
Gravisensing Tip #2 – Kinesiology Tape & Compression Apparel
Remember when kinesiology tape was all the craze with the olympic athletes? This once trendy concept is now sound in research and is strongly validated for the use of increasing joint position sense.
Through the stimulation of subcutaneous fascia and proprioceptors kinesiology tape essentially allows for a faster perception of a shift in the joint. Similarly to tape, compression can also trigger fascial proprioceptors.
One company, Intelliskin, has designed compression apparel with built in PostureCue™ Technology which mimics the effects of kinesiology taping and instantly switches on the muscles that support your posture and align the spine.
Gravisensing Tip #3 – Barefoot Stimulation & Sensory insoles
Our final and of course our favorite recommendation for enhancing body awareness is through stimulation of the feet. Gravity, body and ground interactions are all key components to dynamic movement and upright posture.
The perception of gravity through the ground is statically perceived as pressure but dynamically sensed as vibration. Footwear, especially supportive or cushioned footwear, blocks the sensory stimulation of gravity through our feet.
By getting out of cushioned shoes and into minimal footwear this sensory barrier is decreased, however it is still there. This is where sensory insoles such as those by Naboso Technology come into play. These innovative insoles bring a low profile textured stimulus to the inside of shoes thereby enhancing foot awareness. In fact a 2016 study demonstrated enhanced ankle joint position sense when using textured insoles with dancers.
As we think about the role of gravity in body awareness and optimal movement, I challenge you to think about how these concepts can apply to everyone – from a baby learning to walk to a high performance athlete, and even a patient recovering from a stroke.
The nervous system is a fascinating structure that is shaped, challenged and defined by our relationship to gravity.