Posture is the outward expression of your self-image to the world. That might seem like a fairly esoteric thing to say but consider this; your posture as a child, was excellent. Almost every pre-adolescent child you see moves extremely fluidly, with their head right on top of their shoulders. And this posture required zero conscious effort. No will power whatsoever had to be exerted to maintain it…
…so what happened???
As children enter adolescence they begin to have an idea of how they’re “supposed” to look. Skinny waists and expansive chests are what’s attractive. A “lady” sits with her legs closed. Some of this is conscious, much of it is unconscious. Any teenager who is self-conscious about a part of his or her body will alter muscle tone around that body part, usually to make it less visible. A child who is much taller than his peers often makes himself shorter so as not to be different. A sixth grader with large boobs may feel very shameful about them and round her shoulders to hide them. And once this happens, and the increased tone remains, your nervous system will rewire itself to accommodate this change and it becomes integrated into your personal self-image. Doctor’s may even call you flat footed, pigeon toed, scoliotic, or something similar and it becomes something about yourself that you own. This isn’t exclusive to outward appearance either; x-ray findings of arthritis often label somebody as having a “bad back”, which further alter muscle tone and becomes part of that person’s identity. These kinds of notions about oneself can be very damaging.
Additionally, any activity that induces anxiety will result in inhibition of your diaphragm (which destabilizes you) and cause an increase in flexor tone. This can be very generalized; some people have anxiety every single day and in almost all environments, or it can be very specific to an activity. Most people don’t experience anxiety during tasks that they’re very familiar with or that they’ve been trained in, but put them in a novel situation, or a competitive situation and watch them literally shrink. Conversely, individuals who approach novel situations with a sense of curiosity and confidence will have a very relaxed and upright posture. In this scenario, those children who succeed over and over, develop confidence in their ability to learn new things, and subsequently increase their abilities and confidence to continue to succeed; and their posture expresses itself appropriately. Unfortunately, the opposite happens for many and a downward spiral ensues.
Everyone can recognize the posture of anxiety:
How’s his breathing right now?
Some people live like this.
Any behavior that has an aspect of guilt, fear, shame etc. will always result in a decreased ability to perform a given task and an increase in muscle tension.
A basketball player may be able to shoot foul shots flawlessly in practice, but when those foul shots are needed to win a game, that once automatic neural circuitry gets adulterated with feelings of fear, and the athlete tenses.
Reflexogenic functions, like breathing, posture, sexual function etc. need only spinal cord and brain stem circuits to work optimally. It’s only once the higher levels of our nervous system, the uniquely human parts, where we have an idea of how one “ought” to act, that these functions become adulterated with guilt, fear or shame. How often do you see a dog with distorted posture or sexual frigidity?
So to conclude, your posture is very much an outward expression of your self-image. Feelings of confidence, anxiety, fear etc. will always alter your posture, making you either more or less visible. This is very context dependent; you may have a very upright posture doing your favorite activity, or while intoxicated (and feeling very confident), and then a much smaller, more flexed posture while losing a competition.
Amy Cuddy presented an excellent Ted Talks on how confidence is reflected in your posture and that artificially changing your posture will actually change your physiology. Holding a “power pose” like this:
The fine print with this strategy though is that artificially changing your posture was the problem in the first place. Reflexogenic functions should be controlled reflexogenically, that is, without conscious control. If upright posture isn’t what feels most natural than the reasons need to be investigated and resolved, rather than just consciously overridden. Adding muscle tension to an already tense body won’t result in a very comfortable posture. Proper rehabilitation that allows a person to learn new ways of moving, easier ways of moving, that diminish the need for compulsively held tension, will not only decrease any pain they’re experiencing but allow for the psychologic brakes to be released from their posture and movement patterns.
In fact, any therapy that has a lasting improvement on an individual’s posture will leave that person with an elevated base level of self-confidence. Faced with a new activity they will more likely be curious rather than anxious, and be accompanied with a more relaxed posture. And a relaxed posture will always result in a relaxed mind.