Here’s a thought experiment. Let’s think about all humans as animals, as natural athletes. In nature we don’t see any non athletes, only in domesticated animals. So all the other animals are in natural movement all their lives. Natural here meaning (among other things) being exposed to a vivid array of ever changing landscapes and experiences.
The modern lifestyle is provoking an athleticism of a new kind, one that practices sitting for long periods, or standing in relative stillness for long periods. If most people have around 112 waking hours in a week, the majority of that is spent in stillness, either sitting or standing (assuming a sedentary line of work). A 40 hour work week, plus time for driving, eating, and leisure adds up to a lot of time in the same movement (or lack thereof) pattern.
So then the question is really how is the quality of the movement for folks when they’re not training in sitting, or relative stillness.
When we sit for an hour without moving, it’s a form of training the body. We’re training the body to isometrically contract into the sitting posture. And putting kids into chairs for instance at age 6-18 for school is a form of indoctrination into the sitting body. For some people this is fine, for others it’s pretty disruptive to their natural state. What I observe watching the difference in movement patterning, sitting and standing posture from a 2-4 year old (pre-chair culture) versus a 8-10 year old shows most of the 8-10 year olds are already making strong adaptations into extreme kyphosis or forward head posture (and tucked pelvis) in response to the sitting and mirroring the lack of embodiment in our culture.
Sitting is an isometric exercise. We use energy to sit. The more aligned we are with the gravity field, the more our bony framework can transmit our weight into the ground, and the less energy we expend. Consequently the less weight our bone network takes, the more we will rely on the expensive effort of the connective tissue matrix, muscles, and nervous system to hold this weight.
If we are holding our thoracic spine in extreme kyphosis, with our head jutted out forward, the weight that our muscles need to now hold increases drastically with every mm our head is projected forward of the midline. On average, an adult human head weighs approximately 12lb. Ideally, most of the time your head should be balanced directly above your spine, so that your ear is in line roughly with your shoulder. Physiologists estimate that for every inch the head moves forward from midline the weight of the head increases by 10lbs (which the muscles etc. must support).
So for every hour (moment) a person spends with the head projected forward out of midline balance, they are building nervous system tension activation and coordination, and muscular/ connective tissue tension into the matrix of their body.
We are then literally training our body into this shape. We’re training our perception to ignore the space behind us, one’s back body becomes quite dim in our perception of space behind us, and often the discomfort of the body gets sort of pushed into the subconscious, we generally become less aware of having a body, of being embodied because we are sort of numbing out the awareness of the back body.
When sitting in the same position for a long duration (it’s relative, but generally anything over 20 minutes or so) our body will tend to stagnate, after all we are a body of fluids, mostly liquified, and what happens when you let water sit for too long, it becomes swampy, stagnant..).