Humans are born from a water (reduced gravity) environment into full gravity at about 9 months of development. The increased interaction with gravity facilitates further growth and development. The varying amount that people interact with gravity within their body during physical movements alters body mechanics (and brain volume). For example people who have never walked have ‘Cod Fish’ vertebrae. Those that have walked have structurally different shaped spinal vertebrae. Demonstrating the 10kg of gravity has an effect upon body structure, movement, posture and flexibility.
The human body is made up of chambers, the brain and spine (thecal sac), the abdomen, the lungs (pleura) and heart (pericardium). All of the chambers and abdominal organs interact with each other on a pressure basis. Pressure is a type of force that can alter physiology through the rate of chemical reactions.
Pregnancy and giving birth is a great example of interaction with gravity whilst cavity pressures are challenged. Science has found muscles are used to regulate pressure within the cavities of the human body (See blog post of how intercostal muscle activity is predictive of birthing experience). Illustrating that muscles can be seen as pressure regulating tissue and not just movement devices. Muscles need joints to generate linear and angular forces e.g. a change in direction.
When we consider the wiring (nerve connections) of the body we can see that the brain and spine cavity is linked to the abdominal cavity through venous blood supply. Changes in abdominal pressure was found in Pigs to be 75% passed on to the pleura of their porcine lungs. Demonstrating a link between the abdominal pressure and lung pressure. Pleural pressure and abdominal pressure influences pericardial pressure. The pressure of the heart chamber is wired neurally to the pressure of the eye ball, a known indicator of intracranial pressure. Intracranial pressure is also known as intrathecal (spine and brain) pressure. Pressure dys-regulation in the spine and brain will affect the other chambers of the body, posture and efficiency of movement. Musculature may hold tight, spasm up or go loose to assist in regulation of body cavity pressure, independent of physical tasks. An insidious back spasm.
The brain and spine float in fluid (CSF) protecting them from direct effects of pressure during postural and physical activity tasks. A force applied to water disperses. The sacro-occipital technique system in Chiropractic has categorised patterns of pressure dysregulation of the spine and brain. For example in a Category I diagnosis the base of the spine is stiffened.